SQ overflow seen running isert traffic with high block sizes

SQ overflow seen running isert traffic with high block sizes

[Amrani, Ram]

We are hitting SQ overflow on iSER target side with high block sizes over RoCE
(see dmesg output below).

We are using Q-Logic/Cavium NIC with a capability of 4 sges.

Following the thread "SQ overflow seen running isert traffic" [1], I was wondering
if someone is working on SQ accounting, or more graceful handling of overflow,
as the messages are printed over and over.

Dmesg output:
2017-06-06T09:23:28.824234+05:30 SLES12SP3Beta3 kernel: [65057.799615] isert: isert_rdma_rw_ctx_post: Cmd: ffff880f83cb2cb0 failed to post RDMA res
2017-06-06T09:23:29.500095+05:30 SLES12SP3Beta3 kernel: [65058.475858] isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec53ec020 failed to post RDMA res
2017-06-06T09:23:29.560085+05:30 SLES12SP3Beta3 kernel: [65058.533787] isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec622ae08 failed to post RDMA res
2017-06-06T09:23:29.984209+05:30 SLES12SP3Beta3 kernel: [65058.958509] isert: isert_rdma_rw_ctx_post: Cmd: ffff880ff08e6bb0 failed to post RDMA res
2017-06-06T09:23:30.056098+05:30 SLES12SP3Beta3 kernel: [65059.032182] isert: isert_rdma_rw_ctx_post: Cmd: ffff880fa6761138 failed to post RDMA res
2017-06-06T09:23:30.288152+05:30 SLES12SP3Beta3 kernel: [65059.262748] isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec3caf668 failed to post RDMA res
2017-06-06T09:23:30.444068+05:30 SLES12SP3Beta3 kernel: [65059.421071] isert: isert_rdma_rw_ctx_post: Cmd: ffff880f2186cc30 failed to post RDMA res
2017-06-06T09:23:30.532135+05:30 SLES12SP3Beta3 kernel: [65059.505380] isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec6429bf0 failed to post RDMA res
2017-06-06T09:23:30.672098+05:30 SLES12SP3Beta3 kernel: [65059.645585] isert: isert_rdma_rw_ctx_post: Cmd: ffff880fa5526bb0 failed to post RDMA res
2017-06-06T09:23:30.852121+05:30 SLES12SP3Beta3 kernel: [65059.828072] isert: isert_rdma_rw_ctx_post: Cmd: ffff880f5c8a89d8 failed to post RDMA res
2017-06-06T09:23:31.464125+05:30 SLES12SP3Beta3 kernel: [65060.440092] isert: isert_rdma_rw_ctx_post: Cmd: ffff880ffefdf918 failed to post RDMA res
2017-06-06T09:23:31.576074+05:30 SLES12SP3Beta3 kernel: [65060.550314] isert: isert_rdma_rw_ctx_post: Cmd: ffff880f83222350 failed to post RDMA res
2017-06-06T09:24:30.532064+05:30 SLES12SP3Beta3 kernel: [65119.503466] ABORT_TASK: Found referenced iSCSI task_tag: 103
2017-06-06T09:24:30.532079+05:30 SLES12SP3Beta3 kernel: [65119.503468] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 103
2017-06-06T09:24:31.428084+05:30 SLES12SP3Beta3 kernel: [65120.399433] ABORT_TASK: Found referenced iSCSI task_tag: 101
2017-06-06T09:24:31.428101+05:30 SLES12SP3Beta3 kernel: [65120.399436] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 101
2017-06-06T09:24:31.556053+05:30 SLES12SP3Beta3 kernel: [65120.527461] ABORT_TASK: Found referenced iSCSI task_tag: 119
2017-06-06T09:24:31.556060+05:30 SLES12SP3Beta3 kernel: [65120.527465] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 119
2017-06-06T09:24:31.556061+05:30 SLES12SP3Beta3 kernel: [65120.527468] ABORT_TASK: Found referenced iSCSI task_tag: 43
2017-06-06T09:24:31.556062+05:30 SLES12SP3Beta3 kernel: [65120.527469] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 43
2017-06-06T09:24:31.556063+05:30 SLES12SP3Beta3 kernel: [65120.527470] ABORT_TASK: Found referenced iSCSI task_tag: 79
2017-06-06T09:24:31.556064+05:30 SLES12SP3Beta3 kernel: [65120.527471] ABORT_TASK: Found referenced iSCSI task_tag: 71
2017-06-06T09:24:31.556066+05:30 SLES12SP3Beta3 kernel: [65120.527472] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 79
2017-06-06T09:24:31.556067+05:30 SLES12SP3Beta3 kernel: [65120.527472] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 71
2017-06-06T09:24:31.556068+05:30 SLES12SP3Beta3 kernel: [65120.527506] ABORT_TASK: Found referenced iSCSI task_tag: 122
2017-06-06T09:24:31.556068+05:30 SLES12SP3Beta3 kernel: [65120.527508] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 122
2017-06-06T09:24:32.452073+05:30 SLES12SP3Beta3 kernel: [65121.423425] ABORT_TASK: Found referenced iSCSI task_tag: 58
2017-06-06T09:24:32.452080+05:30 SLES12SP3Beta3 kernel: [65121.423427] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 58
2017-06-06T09:24:32.516054+05:30 SLES12SP3Beta3 kernel: [65121.487380] ABORT_TASK: Found referenced iSCSI task_tag: 100
2017-06-06T09:24:32.516061+05:30 SLES12SP3Beta3 kernel: [65121.487382] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 100
2017-06-06T09:24:32.584031+05:30 SLES12SP3Beta3 kernel: [65121.555374] ABORT_TASK: Found referenced iSCSI task_tag: 52
2017-06-06T09:24:32.584041+05:30 SLES12SP3Beta3 kernel: [65121.555376] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 52
2017-06-06T09:24:33.412057+05:30 SLES12SP3Beta3 kernel: [65122.383341] ABORT_TASK: Found referenced iSCSI task_tag: 43
2017-06-06T09:24:33.412065+05:30 SLES12SP3Beta3 kernel: [65122.383376] ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: 43
2017-06-06T09:24:33.476061+05:30 SLES12SP3Beta3 kernel: [65122.447354] ABORT_TASK: Found referenced iSCSI task_tag: 63
2017-06-06T09:24:33.476070+05:30 SLES12SP3Beta3 kernel: [65122.447360] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 63

[1] https://patchwork.kernel.org/patch/9633675/

Thanks,
Ram
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Potnuri Bharat Teja]

Here is some more discussion regarding SQ overflow.
https://www.spinics.net/lists/linux-rdma/msg47635.html

Current SQ overflow handling is post error handling to keep the IO running and 
We still see SQ post failures filling the dmesg.
We are still working on fixing SQ overflow.

Thanks,
Bharat.

On Wednesday, June 06/28/17, 2017 at 14:55:45 +0530, Amrani, Ram wrote:
>    We are hitting SQ overflow on iSER target side with high block sizes over
>    RoCE
>    (see dmesg output below).
> 
>    We are using Q-Logic/Cavium NIC with a capability of 4 sges.
> 
>    Following the thread "SQ overflow seen running isert traffic" [1], I was
>    wondering
>    if someone is working on SQ accounting, or more graceful handling of
>    overflow,
>    as the messages are printed over and over.
> 
>    Dmesg output:
>    2017-06-06T09:23:28.824234+05:30 SLES12SP3Beta3 kernel: [65057.799615]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880f83cb2cb0 failed to post RDMA
>    res
>    2017-06-06T09:23:29.500095+05:30 SLES12SP3Beta3 kernel: [65058.475858]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec53ec020 failed to post RDMA
>    res
>    2017-06-06T09:23:29.560085+05:30 SLES12SP3Beta3 kernel: [65058.533787]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec622ae08 failed to post RDMA
>    res
>    2017-06-06T09:23:29.984209+05:30 SLES12SP3Beta3 kernel: [65058.958509]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880ff08e6bb0 failed to post RDMA
>    res
>    2017-06-06T09:23:30.056098+05:30 SLES12SP3Beta3 kernel: [65059.032182]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880fa6761138 failed to post RDMA
>    res
>    2017-06-06T09:23:30.288152+05:30 SLES12SP3Beta3 kernel: [65059.262748]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec3caf668 failed to post RDMA
>    res
>    2017-06-06T09:23:30.444068+05:30 SLES12SP3Beta3 kernel: [65059.421071]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880f2186cc30 failed to post RDMA
>    res
>    2017-06-06T09:23:30.532135+05:30 SLES12SP3Beta3 kernel: [65059.505380]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880ec6429bf0 failed to post RDMA
>    res
>    2017-06-06T09:23:30.672098+05:30 SLES12SP3Beta3 kernel: [65059.645585]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880fa5526bb0 failed to post RDMA
>    res
>    2017-06-06T09:23:30.852121+05:30 SLES12SP3Beta3 kernel: [65059.828072]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880f5c8a89d8 failed to post RDMA
>    res
>    2017-06-06T09:23:31.464125+05:30 SLES12SP3Beta3 kernel: [65060.440092]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880ffefdf918 failed to post RDMA
>    res
>    2017-06-06T09:23:31.576074+05:30 SLES12SP3Beta3 kernel: [65060.550314]
>    isert: isert_rdma_rw_ctx_post: Cmd: ffff880f83222350 failed to post RDMA
>    res
>    2017-06-06T09:24:30.532064+05:30 SLES12SP3Beta3 kernel: [65119.503466]
>    ABORT_TASK: Found referenced iSCSI task_tag: 103
>    2017-06-06T09:24:30.532079+05:30 SLES12SP3Beta3 kernel: [65119.503468]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 103
>    2017-06-06T09:24:31.428084+05:30 SLES12SP3Beta3 kernel: [65120.399433]
>    ABORT_TASK: Found referenced iSCSI task_tag: 101
>    2017-06-06T09:24:31.428101+05:30 SLES12SP3Beta3 kernel: [65120.399436]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 101
>    2017-06-06T09:24:31.556053+05:30 SLES12SP3Beta3 kernel: [65120.527461]
>    ABORT_TASK: Found referenced iSCSI task_tag: 119
>    2017-06-06T09:24:31.556060+05:30 SLES12SP3Beta3 kernel: [65120.527465]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 119
>    2017-06-06T09:24:31.556061+05:30 SLES12SP3Beta3 kernel: [65120.527468]
>    ABORT_TASK: Found referenced iSCSI task_tag: 43
>    2017-06-06T09:24:31.556062+05:30 SLES12SP3Beta3 kernel: [65120.527469]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 43
>    2017-06-06T09:24:31.556063+05:30 SLES12SP3Beta3 kernel: [65120.527470]
>    ABORT_TASK: Found referenced iSCSI task_tag: 79
>    2017-06-06T09:24:31.556064+05:30 SLES12SP3Beta3 kernel: [65120.527471]
>    ABORT_TASK: Found referenced iSCSI task_tag: 71
>    2017-06-06T09:24:31.556066+05:30 SLES12SP3Beta3 kernel: [65120.527472]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 79
>    2017-06-06T09:24:31.556067+05:30 SLES12SP3Beta3 kernel: [65120.527472]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 71
>    2017-06-06T09:24:31.556068+05:30 SLES12SP3Beta3 kernel: [65120.527506]
>    ABORT_TASK: Found referenced iSCSI task_tag: 122
>    2017-06-06T09:24:31.556068+05:30 SLES12SP3Beta3 kernel: [65120.527508]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 122
>    2017-06-06T09:24:32.452073+05:30 SLES12SP3Beta3 kernel: [65121.423425]
>    ABORT_TASK: Found referenced iSCSI task_tag: 58
>    2017-06-06T09:24:32.452080+05:30 SLES12SP3Beta3 kernel: [65121.423427]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 58
>    2017-06-06T09:24:32.516054+05:30 SLES12SP3Beta3 kernel: [65121.487380]
>    ABORT_TASK: Found referenced iSCSI task_tag: 100
>    2017-06-06T09:24:32.516061+05:30 SLES12SP3Beta3 kernel: [65121.487382]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 100
>    2017-06-06T09:24:32.584031+05:30 SLES12SP3Beta3 kernel: [65121.555374]
>    ABORT_TASK: Found referenced iSCSI task_tag: 52
>    2017-06-06T09:24:32.584041+05:30 SLES12SP3Beta3 kernel: [65121.555376]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 52
>    2017-06-06T09:24:33.412057+05:30 SLES12SP3Beta3 kernel: [65122.383341]
>    ABORT_TASK: Found referenced iSCSI task_tag: 43
>    2017-06-06T09:24:33.412065+05:30 SLES12SP3Beta3 kernel: [65122.383376]
>    ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: 43
>    2017-06-06T09:24:33.476061+05:30 SLES12SP3Beta3 kernel: [65122.447354]
>    ABORT_TASK: Found referenced iSCSI task_tag: 63
>    2017-06-06T09:24:33.476070+05:30 SLES12SP3Beta3 kernel: [65122.447360]
>    ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 63
> 
>    [1] [1]https://patchwork.kernel.org/patch/9633675/
> 
>    Thanks,
>    Ram
>    --
>    To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
>    the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>    More majordomo info at  [2]http://vger.kernel.org/majordomo-info.html
> 
> References
> 
>    Visible links
>    1. https://patchwork.kernel.org/patch/9633675/
>    2. http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

RE: SQ overflow seen running isert traffic with high block sizes

[Amrani, Ram]

> Here is some more discussion regarding SQ overflow.
> https://www.spinics.net/lists/linux-rdma/msg47635.html
> 
> Current SQ overflow handling is post error handling to keep the IO running and
> We still see SQ post failures filling the dmesg.
> We are still working on fixing SQ overflow.
> 
> Thanks,
> Bharat.

That's good to know.
Let us know when you have something working, we can help test it too.

Thanks,
Ram

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

Hey Ram, CC'ing target-devel for iser-target related posts.

> We are hitting SQ overflow on iSER target side with high block sizes over RoCE
> (see dmesg output below).
> 
> We are using Q-Logic/Cavium NIC with a capability of 4 sges.

That's somewhat expected if the device has low max_sge. It was decided
that queue_full mechanism is not something that iser-target should
handle but rather the iscsi-target core on top.

You probably should not get into aborts though... Does the I/O complete?
or does it fail?

Is this upstream? is [1] applied?

I could come up with some queue-full handling in isert that will be more
lightweight, but I'd let Nic make a judgment call before I do anything.

[1]:
commit a4467018c2a7228f4ef58051f0511bd037bff264
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date:   Sun Oct 30 17:30:08 2016 -0700

     iscsi-target: Propigate queue_data_in + queue_status errors

     This patch changes iscsi-target to propagate iscsit_transport
     ->iscsit_queue_data_in() and ->iscsit_queue_status() callback
     errors, back up into target-core.

     This allows target-core to retry failed iscsit_transport
     callbacks using internal queue-full logic.

     Reported-by: Potnuri Bharat Teja <bharat@chelsio.com>
     Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com>
     Tested-by: Potnuri Bharat Teja <bharat@chelsio.com>
     Cc: Potnuri Bharat Teja <bharat@chelsio.com>
     Reported-by: Steve Wise <swise@opengridcomputing.com>
     Cc: Steve Wise <swise@opengridcomputing.com>
     Cc: Sagi Grimberg <sagi@grimberg.me>
     Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

RE: SQ overflow seen running isert traffic with high block sizes

[Amrani, Ram]

> > We are hitting SQ overflow on iSER target side with high block sizes over RoCE
> > (see dmesg output below).
> >
> > We are using Q-Logic/Cavium NIC with a capability of 4 sges.
> 
> That's somewhat expected if the device has low max_sge. It was decided
> that queue_full mechanism is not something that iser-target should
> handle but rather the iscsi-target core on top.
> 
> You probably should not get into aborts though... Does the I/O complete?
> or does it fail?

The IOs complete

> 
> Is this upstream? is [1] applied?
> 
> I could come up with some queue-full handling in isert that will be more
> lightweight, but I'd let Nic make a judgment call before I do anything.
> 
> [1]:
> commit a4467018c2a7228f4ef58051f0511bd037bff264
> Author: Nicholas Bellinger <nab@linux-iscsi.org>
> Date:   Sun Oct 30 17:30:08 2016 -0700
> 
>      iscsi-target: Propigate queue_data_in + queue_status errors
> 

Yes, the patch is applied.

Thanks,
Ram

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Ram & Co,

(Adding Potnuri CC')

On Wed, 2017-06-28 at 11:32 +0000, Amrani, Ram wrote:
> > > We are hitting SQ overflow on iSER target side with high block sizes over RoCE
> > > (see dmesg output below).
> > >
> > > We are using Q-Logic/Cavium NIC with a capability of 4 sges.
> > 
> > That's somewhat expected if the device has low max_sge. It was decided
> > that queue_full mechanism is not something that iser-target should
> > handle but rather the iscsi-target core on top.
> > 
> > You probably should not get into aborts though... Does the I/O complete?
> > or does it fail?
> 
> The IOs complete
> 
> > 
> > Is this upstream? is [1] applied?
> > 
> > I could come up with some queue-full handling in isert that will be more
> > lightweight, but I'd let Nic make a judgment call before I do anything.
> > 
> > [1]:
> > commit a4467018c2a7228f4ef58051f0511bd037bff264
> > Author: Nicholas Bellinger <nab-IzHhD5pYlfBP7FQvKIMDCQ@public.gmane.org>
> > Date:   Sun Oct 30 17:30:08 2016 -0700
> > 
> >      iscsi-target: Propigate queue_data_in + queue_status errors
> > 
> 
> Yes, the patch is applied.
> 

Just to confirm, the following four patches where required to get
Potnuri up and running on iser-target + iw_cxgb4 with a similarly small
number of hw SGEs:

7a56dc8 iser-target: avoid posting a recv buffer twice
555a65f iser-target: Fix queue-full response handling
a446701 iscsi-target: Propigate queue_data_in + queue_status errors
fa7e25c target: Fix unknown fabric callback queue-full errors

So Did you test with Q-Logic/Cavium with RoCE using these four patches,
or just with commit a4467018..?

Note these have not been CC'ed to stable yet, as I was reluctant since
they didn't have much mileage on them at the time..

Now however, they should be OK to consider for stable, especially if
they get you unblocked as well.









--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

RE: SQ overflow seen running isert traffic with high block sizes

[Amrani, Ram]

Hi Nicholas,

> Just to confirm, the following four patches where required to get
> Potnuri up and running on iser-target + iw_cxgb4 with a similarly small
> number of hw SGEs:
> 
> 7a56dc8 iser-target: avoid posting a recv buffer twice
> 555a65f iser-target: Fix queue-full response handling
> a446701 iscsi-target: Propigate queue_data_in + queue_status errors
> fa7e25c target: Fix unknown fabric callback queue-full errors
> 
> So Did you test with Q-Logic/Cavium with RoCE using these four patches,
> or just with commit a4467018..?
> 
> Note these have not been CC'ed to stable yet, as I was reluctant since
> they didn't have much mileage on them at the time..
> 
> Now however, they should be OK to consider for stable, especially if
> they get you unblocked as well.

The issue is still seen with these four patches.

Thanks,
Ram

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> Hi Nicholas,
> 
> > Just to confirm, the following four patches where required to get
> > Potnuri up and running on iser-target + iw_cxgb4 with a similarly small
> > number of hw SGEs:
> > 
> > 7a56dc8 iser-target: avoid posting a recv buffer twice
> > 555a65f iser-target: Fix queue-full response handling
> > a446701 iscsi-target: Propigate queue_data_in + queue_status errors
> > fa7e25c target: Fix unknown fabric callback queue-full errors
> > 
> > So Did you test with Q-Logic/Cavium with RoCE using these four patches,
> > or just with commit a4467018..?
> > 
> > Note these have not been CC'ed to stable yet, as I was reluctant since
> > they didn't have much mileage on them at the time..
> > 
> > Now however, they should be OK to consider for stable, especially if
> > they get you unblocked as well.
> 
> The issue is still seen with these four patches.
> 
> Thanks,
> Ram

Hi,

On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ overflow being hit on
isert for larger block sizes. 4.14-rc2 kernel.

Eventually there is a timeout/conn-error on iser initiator and the connection is torn down.

The aforementioned patches dont seem to be alleviating the SQ overflow issue?

Initiator
------------

[17007.465524] scsi host11: iSCSI Initiator over iSER
[17007.466295] iscsi: invalid can_queue of 55. can_queue must be a power of 2.
[17007.466924] iscsi: Rounding can_queue to 32.
[17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0  PQ: 0 ANSI: 5
[17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit TPGS
[17007.471656] scsi 11:0:0:0: alua: device naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
[17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
[17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks: (42.9 GB/40.0 GiB)
[17007.472405] sd 11:0:0:0: [sdb] Write Protect is off
[17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
[17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[17007.473412] sd 11:0:0:0: [sdb] Attached SCSI disk
[17007.478184] sd 11:0:0:0: alua: transition timeout set to 60 seconds
[17007.478186] sd 11:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA
[17031.269821]  sdb:
[17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
[17049.056155]  connection2:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4311705998, last ping 4311711232, now 4311716352
[17049.057499]  connection2:0: detected conn error (1022)
[17049.057558] modifyQP to CLOSING qp 3 next_iw_state 3
[..]


Target
----------
[....]
[17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397183] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397183] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397184] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397184] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397192] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397192] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397195] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397196] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
[17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
[17066.397200] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397200] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397204] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397204] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
[17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397211] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397211] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397215] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397215] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
[17066.397219] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397220] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
[17066.397232] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397233] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397238] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397238] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397242] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397242] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3
[17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397251] QP 3 flush_issued
[17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
[17066.397253] Got unknown fabric queue status: -22
[17066.397254] QP 3 flush_issued
[17066.397254] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397254] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
[17066.397255] Got unknown fabric queue status: -22
[17066.397258] QP 3 flush_issued
[17066.397258] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397259] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397259] Got unknown fabric queue status: -22
[17066.397267] QP 3 flush_issued
[17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397268] Got unknown fabric queue status: -22
[17066.397287] QP 3 flush_issued
[17066.397287] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397288] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397288] Got unknown fabric queue status: -22
[17066.397291] QP 3 flush_issued
[17066.397292] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397292] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397292] Got unknown fabric queue status: -22
[17066.397295] QP 3 flush_issued
[17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397297] Got unknown fabric queue status: -22
[17066.397307] QP 3 flush_issued
[17066.397307] i40iw_post_send: qp 3 wr_opcode 8 ret_err -22
[17066.397308] isert: isert_post_response: ib_post_send failed with -22
[17066.397309] i40iw i40iw_qp_disconnect Call close API
[....]

Shiraz 
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> Hi Nicholas,
> 
> > Just to confirm, the following four patches where required to get
> > Potnuri up and running on iser-target + iw_cxgb4 with a similarly small
> > number of hw SGEs:
> > 
> > 7a56dc8 iser-target: avoid posting a recv buffer twice
> > 555a65f iser-target: Fix queue-full response handling
> > a446701 iscsi-target: Propigate queue_data_in + queue_status errors
> > fa7e25c target: Fix unknown fabric callback queue-full errors
> > 
> > So Did you test with Q-Logic/Cavium with RoCE using these four patches,
> > or just with commit a4467018..?
> > 
> > Note these have not been CC'ed to stable yet, as I was reluctant since
> > they didn't have much mileage on them at the time..
> > 
> > Now however, they should be OK to consider for stable, especially if
> > they get you unblocked as well.
> 
> The issue is still seen with these four patches.
> 
> Thanks,
> Ram

Hi,

On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ overflow being hit on
isert for larger block sizes. 4.14-rc2 kernel.

Eventually there is a timeout/conn-error on iser initiator and the connection is torn down.

The aforementioned patches dont seem to be alleviating the SQ overflow issue?

Initiator
------------

[17007.465524] scsi host11: iSCSI Initiator over iSER
[17007.466295] iscsi: invalid can_queue of 55. can_queue must be a power of 2.
[17007.466924] iscsi: Rounding can_queue to 32.
[17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0  PQ: 0 ANSI: 5
[17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit TPGS
[17007.471656] scsi 11:0:0:0: alua: device naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
[17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
[17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks: (42.9 GB/40.0 GiB)
[17007.472405] sd 11:0:0:0: [sdb] Write Protect is off
[17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
[17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[17007.473412] sd 11:0:0:0: [sdb] Attached SCSI disk
[17007.478184] sd 11:0:0:0: alua: transition timeout set to 60 seconds
[17007.478186] sd 11:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA
[17031.269821]  sdb:
[17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
[17049.056155]  connection2:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4311705998, last ping 4311711232, now 4311716352
[17049.057499]  connection2:0: detected conn error (1022)
[17049.057558] modifyQP to CLOSING qp 3 next_iw_state 3
[..]


Target
----------
[....]
[17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397183] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397183] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397184] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397184] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397192] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397192] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397195] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397196] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
[17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
[17066.397200] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397200] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397204] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397204] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
[17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397211] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397211] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397215] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397215] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
[17066.397219] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397220] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
[17066.397232] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397233] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397238] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397238] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397242] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397242] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
[17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3
[17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397251] QP 3 flush_issued
[17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
[17066.397253] Got unknown fabric queue status: -22
[17066.397254] QP 3 flush_issued
[17066.397254] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397254] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
[17066.397255] Got unknown fabric queue status: -22
[17066.397258] QP 3 flush_issued
[17066.397258] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397259] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
[17066.397259] Got unknown fabric queue status: -22
[17066.397267] QP 3 flush_issued
[17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
[17066.397268] Got unknown fabric queue status: -22
[17066.397287] QP 3 flush_issued
[17066.397287] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397288] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
[17066.397288] Got unknown fabric queue status: -22
[17066.397291] QP 3 flush_issued
[17066.397292] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397292] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
[17066.397292] Got unknown fabric queue status: -22
[17066.397295] QP 3 flush_issued
[17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
[17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
[17066.397297] Got unknown fabric queue status: -22
[17066.397307] QP 3 flush_issued
[17066.397307] i40iw_post_send: qp 3 wr_opcode 8 ret_err -22
[17066.397308] isert: isert_post_response: ib_post_send failed with -22
[17066.397309] i40iw i40iw_qp_disconnect Call close API
[....]

Shiraz 

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Shiraz, Ram, Ariel, & Potnuri,

Following up on this old thread, as it relates to Potnuri's recent fix
for a iser-target queue-full memory leak:

https://www.spinics.net/lists/target-devel/msg16282.html

Just curious how frequent this happens in practice with sustained large
block workloads, as it appears to effect at least three different
iwarp RNICS (i40iw, qedr and iw_cxgb4)..?

Is there anything else from an iser-target consumer level that should be
changed for iwarp to avoid repeated ib_post_send() failures..?

On Fri, 2017-10-06 at 17:40 -0500, Shiraz Saleem wrote:
> On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> > Hi Nicholas,
> > 
> > > Just to confirm, the following four patches where required to get
> > > Potnuri up and running on iser-target + iw_cxgb4 with a similarly small
> > > number of hw SGEs:
> > > 
> > > 7a56dc8 iser-target: avoid posting a recv buffer twice
> > > 555a65f iser-target: Fix queue-full response handling
> > > a446701 iscsi-target: Propigate queue_data_in + queue_status errors
> > > fa7e25c target: Fix unknown fabric callback queue-full errors
> > > 
> > > So Did you test with Q-Logic/Cavium with RoCE using these four patches,
> > > or just with commit a4467018..?
> > > 
> > > Note these have not been CC'ed to stable yet, as I was reluctant since
> > > they didn't have much mileage on them at the time..
> > > 
> > > Now however, they should be OK to consider for stable, especially if
> > > they get you unblocked as well.
> > 
> > The issue is still seen with these four patches.
> > 
> > Thanks,
> > Ram
> 
> Hi,
> 
> On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ overflow being hit on
> isert for larger block sizes. 4.14-rc2 kernel.
> 
> Eventually there is a timeout/conn-error on iser initiator and the connection is torn down.
> 
> The aforementioned patches dont seem to be alleviating the SQ overflow issue?
> 
> Initiator
> ------------
> 
> [17007.465524] scsi host11: iSCSI Initiator over iSER
> [17007.466295] iscsi: invalid can_queue of 55. can_queue must be a power of 2.
> [17007.466924] iscsi: Rounding can_queue to 32.
> [17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0  PQ: 0 ANSI: 5
> [17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit TPGS
> [17007.471656] scsi 11:0:0:0: alua: device naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
> [17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
> [17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks: (42.9 GB/40.0 GiB)
> [17007.472405] sd 11:0:0:0: [sdb] Write Protect is off
> [17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
> [17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
> [17007.473412] sd 11:0:0:0: [sdb] Attached SCSI disk
> [17007.478184] sd 11:0:0:0: alua: transition timeout set to 60 seconds
> [17007.478186] sd 11:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA
> [17031.269821]  sdb:
> [17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
> [17049.056155]  connection2:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4311705998, last ping 4311711232, now 4311716352
> [17049.057499]  connection2:0: detected conn error (1022)
> [17049.057558] modifyQP to CLOSING qp 3 next_iw_state 3
> [..]
> 
> 
> Target
> ----------
> [....]
> [17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397183] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397183] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397184] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397184] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397192] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397192] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397195] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397196] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> [17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> [17066.397200] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397200] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397204] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397204] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
> [17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397211] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397211] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397215] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397215] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> [17066.397219] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397220] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> [17066.397232] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397233] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397238] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397238] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397242] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397242] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3
> [17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397251] QP 3 flush_issued
> [17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> [17066.397253] Got unknown fabric queue status: -22
> [17066.397254] QP 3 flush_issued
> [17066.397254] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397254] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> [17066.397255] Got unknown fabric queue status: -22
> [17066.397258] QP 3 flush_issued
> [17066.397258] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397259] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397259] Got unknown fabric queue status: -22
> [17066.397267] QP 3 flush_issued
> [17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397268] Got unknown fabric queue status: -22
> [17066.397287] QP 3 flush_issued
> [17066.397287] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397288] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397288] Got unknown fabric queue status: -22
> [17066.397291] QP 3 flush_issued
> [17066.397292] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397292] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397292] Got unknown fabric queue status: -22
> [17066.397295] QP 3 flush_issued
> [17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397297] Got unknown fabric queue status: -22
> [17066.397307] QP 3 flush_issued
> [17066.397307] i40iw_post_send: qp 3 wr_opcode 8 ret_err -22
> [17066.397308] isert: isert_post_response: ib_post_send failed with -22
> [17066.397309] i40iw i40iw_qp_disconnect Call close API
> [....]
> 
> Shiraz 
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Shiraz, Ram, Ariel, & Potnuri,

Following up on this old thread, as it relates to Potnuri's recent fix
for a iser-target queue-full memory leak:

https://www.spinics.net/lists/target-devel/msg16282.html

Just curious how frequent this happens in practice with sustained large
block workloads, as it appears to effect at least three different
iwarp RNICS (i40iw, qedr and iw_cxgb4)..?

Is there anything else from an iser-target consumer level that should be
changed for iwarp to avoid repeated ib_post_send() failures..?

On Fri, 2017-10-06 at 17:40 -0500, Shiraz Saleem wrote:
> On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> > Hi Nicholas,
> > 
> > > Just to confirm, the following four patches where required to get
> > > Potnuri up and running on iser-target + iw_cxgb4 with a similarly small
> > > number of hw SGEs:
> > > 
> > > 7a56dc8 iser-target: avoid posting a recv buffer twice
> > > 555a65f iser-target: Fix queue-full response handling
> > > a446701 iscsi-target: Propigate queue_data_in + queue_status errors
> > > fa7e25c target: Fix unknown fabric callback queue-full errors
> > > 
> > > So Did you test with Q-Logic/Cavium with RoCE using these four patches,
> > > or just with commit a4467018..?
> > > 
> > > Note these have not been CC'ed to stable yet, as I was reluctant since
> > > they didn't have much mileage on them at the time..
> > > 
> > > Now however, they should be OK to consider for stable, especially if
> > > they get you unblocked as well.
> > 
> > The issue is still seen with these four patches.
> > 
> > Thanks,
> > Ram
> 
> Hi,
> 
> On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ overflow being hit on
> isert for larger block sizes. 4.14-rc2 kernel.
> 
> Eventually there is a timeout/conn-error on iser initiator and the connection is torn down.
> 
> The aforementioned patches dont seem to be alleviating the SQ overflow issue?
> 
> Initiator
> ------------
> 
> [17007.465524] scsi host11: iSCSI Initiator over iSER
> [17007.466295] iscsi: invalid can_queue of 55. can_queue must be a power of 2.
> [17007.466924] iscsi: Rounding can_queue to 32.
> [17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0  PQ: 0 ANSI: 5
> [17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit TPGS
> [17007.471656] scsi 11:0:0:0: alua: device naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
> [17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
> [17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks: (42.9 GB/40.0 GiB)
> [17007.472405] sd 11:0:0:0: [sdb] Write Protect is off
> [17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
> [17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
> [17007.473412] sd 11:0:0:0: [sdb] Attached SCSI disk
> [17007.478184] sd 11:0:0:0: alua: transition timeout set to 60 seconds
> [17007.478186] sd 11:0:0:0: alua: port group 00 state A non-preferred supports TOlUSNA
> [17031.269821]  sdb:
> [17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
> [17049.056155]  connection2:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4311705998, last ping 4311711232, now 4311716352
> [17049.057499]  connection2:0: detected conn error (1022)
> [17049.057558] modifyQP to CLOSING qp 3 next_iw_state 3
> [..]
> 
> 
> Target
> ----------
> [....]
> [17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397183] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397183] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397184] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397184] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397192] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397192] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397195] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397196] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> [17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> [17066.397200] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397200] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397204] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397204] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
> [17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397211] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397211] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397215] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397215] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> [17066.397219] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397220] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> [17066.397232] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397233] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397238] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397238] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397242] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397242] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3
> [17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397251] QP 3 flush_issued
> [17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> [17066.397253] Got unknown fabric queue status: -22
> [17066.397254] QP 3 flush_issued
> [17066.397254] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397254] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> [17066.397255] Got unknown fabric queue status: -22
> [17066.397258] QP 3 flush_issued
> [17066.397258] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397259] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> [17066.397259] Got unknown fabric queue status: -22
> [17066.397267] QP 3 flush_issued
> [17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> [17066.397268] Got unknown fabric queue status: -22
> [17066.397287] QP 3 flush_issued
> [17066.397287] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397288] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> [17066.397288] Got unknown fabric queue status: -22
> [17066.397291] QP 3 flush_issued
> [17066.397292] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397292] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> [17066.397292] Got unknown fabric queue status: -22
> [17066.397295] QP 3 flush_issued
> [17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> [17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> [17066.397297] Got unknown fabric queue status: -22
> [17066.397307] QP 3 flush_issued
> [17066.397307] i40iw_post_send: qp 3 wr_opcode 8 ret_err -22
> [17066.397308] isert: isert_post_response: ib_post_send failed with -22
> [17066.397309] i40iw i40iw_qp_disconnect Call close API
> [....]
> 
> Shiraz 
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

RE: SQ overflow seen running isert traffic with high block sizes

[Kalderon, Michal]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 10474 bytes --]

> From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> Sent: Monday, January 15, 2018 6:57 AM
> To: Shiraz Saleem <shiraz.saleem@intel.com>
> Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> Potnuri Bharat Teja <bharat@chelsio.com>
> Subject: Re: SQ overflow seen running isert traffic with high block sizes
> 
> Hi Shiraz, Ram, Ariel, & Potnuri,
> 
> Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> target queue-full memory leak:
> 
> https://www.spinics.net/lists/target-devel/msg16282.html
> 
> Just curious how frequent this happens in practice with sustained large block
> workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> qedr and iw_cxgb4)..?
> 
> Is there anything else from an iser-target consumer level that should be
> changed for iwarp to avoid repeated ib_post_send() failures..?
> 
Would like to mention, that although we are an iWARP RNIC as well, we've hit this
Issue when running RoCE. It's not iWARP related. 
This is easily reproduced within seconds with IO size of 5121K
Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.

IO Command used:
maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1

thanks,
Michal

> On Fri, 2017-10-06 at 17:40 -0500, Shiraz Saleem wrote:
> > On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> > > Hi Nicholas,
> > >
> > > > Just to confirm, the following four patches where required to get
> > > > Potnuri up and running on iser-target + iw_cxgb4 with a similarly
> > > > small number of hw SGEs:
> > > >
> > > > 7a56dc8 iser-target: avoid posting a recv buffer twice 555a65f
> > > > iser-target: Fix queue-full response handling
> > > > a446701 iscsi-target: Propigate queue_data_in + queue_status
> > > > errors fa7e25c target: Fix unknown fabric callback queue-full
> > > > errors
> > > >
> > > > So Did you test with Q-Logic/Cavium with RoCE using these four
> > > > patches, or just with commit a4467018..?
> > > >
> > > > Note these have not been CC'ed to stable yet, as I was reluctant
> > > > since they didn't have much mileage on them at the time..
> > > >
> > > > Now however, they should be OK to consider for stable, especially
> > > > if they get you unblocked as well.
> > >
> > > The issue is still seen with these four patches.
> > >
> > > Thanks,
> > > Ram
> >
> > Hi,
> >
> > On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ
> > overflow being hit on isert for larger block sizes. 4.14-rc2 kernel.
> >
> > Eventually there is a timeout/conn-error on iser initiator and the
> connection is torn down.
> >
> > The aforementioned patches dont seem to be alleviating the SQ overflow
> issue?
> >
> > Initiator
> > ------------
> >
> > [17007.465524] scsi host11: iSCSI Initiator over iSER [17007.466295]
> > iscsi: invalid can_queue of 55. can_queue must be a power of 2.
> > [17007.466924] iscsi: Rounding can_queue to 32.
> > [17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0
> PQ: 0 ANSI: 5
> > [17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit
> > TPGS [17007.471656] scsi 11:0:0:0: alua: device
> > naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
> > [17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
> > [17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks:
> > (42.9 GB/40.0 GiB) [17007.472405] sd 11:0:0:0: [sdb] Write Protect is
> > off [17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
> > [17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache:
> > enabled, doesn't support DPO or FUA [17007.473412] sd 11:0:0:0: [sdb]
> > Attached SCSI disk [17007.478184] sd 11:0:0:0: alua: transition
> > timeout set to 60 seconds [17007.478186] sd 11:0:0:0: alua: port group 00
> state A non-preferred supports TOlUSNA [17031.269821]  sdb:
> > [17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data
> > mode. Opts: (null) [17049.056155]  connection2:0: ping timeout of 5
> > secs expired, recv timeout 5, last rx 4311705998, last ping
> > 4311711232, now 4311716352 [17049.057499]  connection2:0: detected
> > conn error (1022) [17049.057558] modifyQP to CLOSING qp 3
> > next_iw_state 3 [..]
> >
> >
> > Target
> > ----------
> > [....]
> > [17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020
> > failed to post RDMA res [17066.397183] i40iw_post_send: qp 3 wr_opcode
> > 0 ret_err -12 [17066.397183] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8ea1f8 failed to post RDMA res [17066.397184]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397184] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> > [17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30
> > failed to post RDMA res [17066.397192] i40iw_post_send: qp 3 wr_opcode
> > 0 ret_err -12 [17066.397192] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8f20a0 failed to post RDMA res [17066.397195]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397196] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> > [17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48
> > failed to post RDMA res [17066.397200] i40iw_post_send: qp 3 wr_opcode
> > 0 ret_err -12 [17066.397200] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8ec020 failed to post RDMA res [17066.397204]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397204] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> > [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id =
> > 3 [17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0
> > failed to post RDMA res [17066.397211] i40iw_post_send: qp 3 wr_opcode
> > 0 ret_err -12 [17066.397211] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8ecc30 failed to post RDMA res [17066.397215]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397215] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> > [17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800
> > failed to post RDMA res [17066.397219] i40iw_post_send: qp 3 wr_opcode
> > 0 ret_err -12 [17066.397220] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8ede48 failed to post RDMA res [17066.397232]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397233] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> > [17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8
> > failed to post RDMA res [17066.397238] i40iw_post_send: qp 3 wr_opcode
> > 0 ret_err -12 [17066.397238] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8e9bf0 failed to post RDMA res [17066.397242]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397242] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> > [17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id =
> > 3 [17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0
> > failed to post RDMA res [17066.397251] QP 3 flush_issued
> > [17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > [17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800
> > failed to post RDMA res [17066.397253] Got unknown fabric queue
> > status: -22 [17066.397254] QP 3 flush_issued [17066.397254]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -22 [17066.397254] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> > [17066.397255] Got unknown fabric queue status: -22 [17066.397258] QP
> > 3 flush_issued [17066.397258] i40iw_post_send: qp 3 wr_opcode 0
> > ret_err -22 [17066.397259] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8ec020 failed to post RDMA res [17066.397259] Got unknown
> > fabric queue status: -22 [17066.397267] QP 3 flush_issued
> > [17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > [17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8
> > failed to post RDMA res [17066.397268] Got unknown fabric queue
> > status: -22 [17066.397287] QP 3 flush_issued [17066.397287]
> > i40iw_post_send: qp 3 wr_opcode 0 ret_err -22 [17066.397288] isert:
> > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> > [17066.397288] Got unknown fabric queue status: -22 [17066.397291] QP
> > 3 flush_issued [17066.397292] i40iw_post_send: qp 3 wr_opcode 0
> > ret_err -22 [17066.397292] isert: isert_rdma_rw_ctx_post: Cmd:
> > ffff8817fb8ecc30 failed to post RDMA res [17066.397292] Got unknown
> > fabric queue status: -22 [17066.397295] QP 3 flush_issued
> > [17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > [17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0
> > failed to post RDMA res [17066.397297] Got unknown fabric queue
> > status: -22 [17066.397307] QP 3 flush_issued [17066.397307]
> > i40iw_post_send: qp 3 wr_opcode 8 ret_err -22 [17066.397308] isert:
> > isert_post_response: ib_post_send failed with -22 [17066.397309] i40iw
> > i40iw_qp_disconnect Call close API [....]
> >
> > Shiraz
> > --
> > To unsubscribe from this list: send the line "unsubscribe
> > target-devel" in the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the
> body of a message to majordomo@vger.kernel.org More majordomo info at
> http://vger.kernel.org/majordomo-info.html
N‹§²æìr¸›yúèšØb²X¬¶Ç§vØ^–)Þº{.nÇ+‰·¥Š{±­ÙšŠ{ayº\x1dʇڙë,j\a­¢f£¢·hš‹»öì\x17/oSc¾™Ú³9˜uÀ¦æå‰È&jw¨®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿïêäz¹Þ–Šàþf£¢·hšˆ§~ˆmš

RE: SQ overflow seen running isert traffic with high block sizes

[Kalderon, Michal]
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Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > From: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-rdma-
> > owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Nicholas A. Bellinger
> > Sent: Monday, January 15, 2018 6:57 AM
> > To: Shiraz Saleem <shiraz.saleem-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > Cc: Amrani, Ram <Ram.Amrani-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>; Sagi Grimberg
> > <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Elior, Ariel
> > <Ariel.Elior-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>; target-devel <target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>;
> > Potnuri Bharat Teja <bharat-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
> > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > 
> > Hi Shiraz, Ram, Ariel, & Potnuri,
> > 
> > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > target queue-full memory leak:
> > 
> > https://www.spinics.net/lists/target-devel/msg16282.html
> > 
> > Just curious how frequent this happens in practice with sustained large block
> > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > qedr and iw_cxgb4)..?
> > 
> > Is there anything else from an iser-target consumer level that should be
> > changed for iwarp to avoid repeated ib_post_send() failures..?
> > 
> Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> Issue when running RoCE. It's not iWARP related. 
> This is easily reproduced within seconds with IO size of 5121K
> Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> 
> IO Command used:
> maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> 
> thanks,
> Michal

Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
rather quickly, in a matter of seconds.

fio --rw=read --bs=2048k --numjobs=1 --iodepth=128 --runtime=30 --size=20g --loops=1 --ioengine=libaio 
--direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 

Shiraz

> 
> > On Fri, 2017-10-06 at 17:40 -0500, Shiraz Saleem wrote:
> > > On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> > > > Hi Nicholas,
> > > >
> > > > > Just to confirm, the following four patches where required to get
> > > > > Potnuri up and running on iser-target + iw_cxgb4 with a similarly
> > > > > small number of hw SGEs:
> > > > >
> > > > > 7a56dc8 iser-target: avoid posting a recv buffer twice 555a65f
> > > > > iser-target: Fix queue-full response handling
> > > > > a446701 iscsi-target: Propigate queue_data_in + queue_status
> > > > > errors fa7e25c target: Fix unknown fabric callback queue-full
> > > > > errors
> > > > >
> > > > > So Did you test with Q-Logic/Cavium with RoCE using these four
> > > > > patches, or just with commit a4467018..?
> > > > >
> > > > > Note these have not been CC'ed to stable yet, as I was reluctant
> > > > > since they didn't have much mileage on them at the time..
> > > > >
> > > > > Now however, they should be OK to consider for stable, especially
> > > > > if they get you unblocked as well.
> > > >
> > > > The issue is still seen with these four patches.
> > > >
> > > > Thanks,
> > > > Ram
> > >
> > > Hi,
> > >
> > > On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ
> > > overflow being hit on isert for larger block sizes. 4.14-rc2 kernel.
> > >
> > > Eventually there is a timeout/conn-error on iser initiator and the
> > connection is torn down.
> > >
> > > The aforementioned patches dont seem to be alleviating the SQ overflow
> > issue?
> > >
> > > Initiator
> > > ------------
> > >
> > > [17007.465524] scsi host11: iSCSI Initiator over iSER [17007.466295]
> > > iscsi: invalid can_queue of 55. can_queue must be a power of 2.
> > > [17007.466924] iscsi: Rounding can_queue to 32.
> > > [17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0
> > PQ: 0 ANSI: 5
> > > [17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit
> > > TPGS [17007.471656] scsi 11:0:0:0: alua: device
> > > naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
> > > [17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
> > > [17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks:
> > > (42.9 GB/40.0 GiB) [17007.472405] sd 11:0:0:0: [sdb] Write Protect is
> > > off [17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
> > > [17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache:
> > > enabled, doesn't support DPO or FUA [17007.473412] sd 11:0:0:0: [sdb]
> > > Attached SCSI disk [17007.478184] sd 11:0:0:0: alua: transition
> > > timeout set to 60 seconds [17007.478186] sd 11:0:0:0: alua: port group 00
> > state A non-preferred supports TOlUSNA [17031.269821]  sdb:
> > > [17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data
> > > mode. Opts: (null) [17049.056155]  connection2:0: ping timeout of 5
> > > secs expired, recv timeout 5, last rx 4311705998, last ping
> > > 4311711232, now 4311716352 [17049.057499]  connection2:0: detected
> > > conn error (1022) [17049.057558] modifyQP to CLOSING qp 3
> > > next_iw_state 3 [..]
> > >
> > >
> > > Target
> > > ----------
> > > [....]
> > > [17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020
> > > failed to post RDMA res [17066.397183] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397183] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ea1f8 failed to post RDMA res [17066.397184]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397184] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> > > [17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30
> > > failed to post RDMA res [17066.397192] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397192] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8f20a0 failed to post RDMA res [17066.397195]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397196] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> > > [17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48
> > > failed to post RDMA res [17066.397200] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397200] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ec020 failed to post RDMA res [17066.397204]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397204] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> > > [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id =
> > > 3 [17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0
> > > failed to post RDMA res [17066.397211] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397211] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ecc30 failed to post RDMA res [17066.397215]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397215] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> > > [17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800
> > > failed to post RDMA res [17066.397219] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397220] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ede48 failed to post RDMA res [17066.397232]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397233] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> > > [17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8
> > > failed to post RDMA res [17066.397238] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397238] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8e9bf0 failed to post RDMA res [17066.397242]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397242] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> > > [17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id =
> > > 3 [17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0
> > > failed to post RDMA res [17066.397251] QP 3 flush_issued
> > > [17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > > [17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800
> > > failed to post RDMA res [17066.397253] Got unknown fabric queue
> > > status: -22 [17066.397254] QP 3 flush_issued [17066.397254]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -22 [17066.397254] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> > > [17066.397255] Got unknown fabric queue status: -22 [17066.397258] QP
> > > 3 flush_issued [17066.397258] i40iw_post_send: qp 3 wr_opcode 0
> > > ret_err -22 [17066.397259] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ec020 failed to post RDMA res [17066.397259] Got unknown
> > > fabric queue status: -22 [17066.397267] QP 3 flush_issued
> > > [17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > > [17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8
> > > failed to post RDMA res [17066.397268] Got unknown fabric queue
> > > status: -22 [17066.397287] QP 3 flush_issued [17066.397287]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -22 [17066.397288] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> > > [17066.397288] Got unknown fabric queue status: -22 [17066.397291] QP
> > > 3 flush_issued [17066.397292] i40iw_post_send: qp 3 wr_opcode 0
> > > ret_err -22 [17066.397292] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ecc30 failed to post RDMA res [17066.397292] Got unknown
> > > fabric queue status: -22 [17066.397295] QP 3 flush_issued
> > > [17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > > [17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0
> > > failed to post RDMA res [17066.397297] Got unknown fabric queue
> > > status: -22 [17066.397307] QP 3 flush_issued [17066.397307]
> > > i40iw_post_send: qp 3 wr_opcode 8 ret_err -22 [17066.397308] isert:
> > > isert_post_response: ib_post_send failed with -22 [17066.397309] i40iw
> > > i40iw_qp_disconnect Call close API [....]
> > >
> > > Shiraz
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe
> > > target-devel" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the
> > body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at
> > http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > Sent: Monday, January 15, 2018 6:57 AM
> > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > Potnuri Bharat Teja <bharat@chelsio.com>
> > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > 
> > Hi Shiraz, Ram, Ariel, & Potnuri,
> > 
> > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > target queue-full memory leak:
> > 
> > https://www.spinics.net/lists/target-devel/msg16282.html
> > 
> > Just curious how frequent this happens in practice with sustained large block
> > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > qedr and iw_cxgb4)..?
> > 
> > Is there anything else from an iser-target consumer level that should be
> > changed for iwarp to avoid repeated ib_post_send() failures..?
> > 
> Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> Issue when running RoCE. It's not iWARP related. 
> This is easily reproduced within seconds with IO size of 5121K
> Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> 
> IO Command used:
> maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> 
> thanks,
> Michal

Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
rather quickly, in a matter of seconds.

fio --rw=read --bs 48k --numjobs=1 --iodepth\x128 --runtime0 --size g --loops=1 --ioengine=libaio 
--direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 

Shiraz

> 
> > On Fri, 2017-10-06 at 17:40 -0500, Shiraz Saleem wrote:
> > > On Mon, Jul 17, 2017 at 03:26:04AM -0600, Amrani, Ram wrote:
> > > > Hi Nicholas,
> > > >
> > > > > Just to confirm, the following four patches where required to get
> > > > > Potnuri up and running on iser-target + iw_cxgb4 with a similarly
> > > > > small number of hw SGEs:
> > > > >
> > > > > 7a56dc8 iser-target: avoid posting a recv buffer twice 555a65f
> > > > > iser-target: Fix queue-full response handling
> > > > > a446701 iscsi-target: Propigate queue_data_in + queue_status
> > > > > errors fa7e25c target: Fix unknown fabric callback queue-full
> > > > > errors
> > > > >
> > > > > So Did you test with Q-Logic/Cavium with RoCE using these four
> > > > > patches, or just with commit a4467018..?
> > > > >
> > > > > Note these have not been CC'ed to stable yet, as I was reluctant
> > > > > since they didn't have much mileage on them at the time..
> > > > >
> > > > > Now however, they should be OK to consider for stable, especially
> > > > > if they get you unblocked as well.
> > > >
> > > > The issue is still seen with these four patches.
> > > >
> > > > Thanks,
> > > > Ram
> > >
> > > Hi,
> > >
> > > On X722 Iwarp NICs (i40iw) too, we are seeing a similar issue of SQ
> > > overflow being hit on isert for larger block sizes. 4.14-rc2 kernel.
> > >
> > > Eventually there is a timeout/conn-error on iser initiator and the
> > connection is torn down.
> > >
> > > The aforementioned patches dont seem to be alleviating the SQ overflow
> > issue?
> > >
> > > Initiator
> > > ------------
> > >
> > > [17007.465524] scsi host11: iSCSI Initiator over iSER [17007.466295]
> > > iscsi: invalid can_queue of 55. can_queue must be a power of 2.
> > > [17007.466924] iscsi: Rounding can_queue to 32.
> > > [17007.471535] scsi 11:0:0:0: Direct-Access     LIO-ORG  ramdisk1_40G     4.0
> > PQ: 0 ANSI: 5
> > > [17007.471652] scsi 11:0:0:0: alua: supports implicit and explicit
> > > TPGS [17007.471656] scsi 11:0:0:0: alua: device
> > > naa.6001405ab790db5e8e94b0998ab4bf0b port group 0 rel port 1
> > > [17007.471782] sd 11:0:0:0: Attached scsi generic sg2 type 0
> > > [17007.472373] sd 11:0:0:0: [sdb] 83886080 512-byte logical blocks:
> > > (42.9 GB/40.0 GiB) [17007.472405] sd 11:0:0:0: [sdb] Write Protect is
> > > off [17007.472406] sd 11:0:0:0: [sdb] Mode Sense: 43 00 00 08
> > > [17007.472462] sd 11:0:0:0: [sdb] Write cache: disabled, read cache:
> > > enabled, doesn't support DPO or FUA [17007.473412] sd 11:0:0:0: [sdb]
> > > Attached SCSI disk [17007.478184] sd 11:0:0:0: alua: transition
> > > timeout set to 60 seconds [17007.478186] sd 11:0:0:0: alua: port group 00
> > state A non-preferred supports TOlUSNA [17031.269821]  sdb:
> > > [17033.359789] EXT4-fs (sdb1): mounted filesystem with ordered data
> > > mode. Opts: (null) [17049.056155]  connection2:0: ping timeout of 5
> > > secs expired, recv timeout 5, last rx 4311705998, last ping
> > > 4311711232, now 4311716352 [17049.057499]  connection2:0: detected
> > > conn error (1022) [17049.057558] modifyQP to CLOSING qp 3
> > > next_iw_state 3 [..]
> > >
> > >
> > > Target
> > > ----------
> > > [....]
> > > [17066.397179] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397180] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020
> > > failed to post RDMA res [17066.397183] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397183] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ea1f8 failed to post RDMA res [17066.397184]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397184] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> > > [17066.397187] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397188] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30
> > > failed to post RDMA res [17066.397192] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397192] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8f20a0 failed to post RDMA res [17066.397195]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397196] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800 failed to post RDMA res
> > > [17066.397196] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397197] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48
> > > failed to post RDMA res [17066.397200] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397200] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ec020 failed to post RDMA res [17066.397204]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397204] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8 failed to post RDMA res
> > > [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id > > > 3 [17066.397207] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397207] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0
> > > failed to post RDMA res [17066.397211] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397211] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ecc30 failed to post RDMA res [17066.397215]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397215] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0 failed to post RDMA res
> > > [17066.397218] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397219] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800
> > > failed to post RDMA res [17066.397219] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397220] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ede48 failed to post RDMA res [17066.397232]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397233] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ec020 failed to post RDMA res
> > > [17066.397237] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397237] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8
> > > failed to post RDMA res [17066.397238] i40iw_post_send: qp 3 wr_opcode
> > > 0 ret_err -12 [17066.397238] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8e9bf0 failed to post RDMA res [17066.397242]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -12 [17066.397242] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ecc30 failed to post RDMA res
> > > [17066.397245] i40iw_post_send: qp 3 wr_opcode 0 ret_err -12
> > > [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id > > > 3 [17066.397247] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0
> > > failed to post RDMA res [17066.397251] QP 3 flush_issued
> > > [17066.397252] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > > [17066.397252] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea800
> > > failed to post RDMA res [17066.397253] Got unknown fabric queue
> > > status: -22 [17066.397254] QP 3 flush_issued [17066.397254]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -22 [17066.397254] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ede48 failed to post RDMA res
> > > [17066.397255] Got unknown fabric queue status: -22 [17066.397258] QP
> > > 3 flush_issued [17066.397258] i40iw_post_send: qp 3 wr_opcode 0
> > > ret_err -22 [17066.397259] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ec020 failed to post RDMA res [17066.397259] Got unknown
> > > fabric queue status: -22 [17066.397267] QP 3 flush_issued
> > > [17066.397267] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > > [17066.397268] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8ea1f8
> > > failed to post RDMA res [17066.397268] Got unknown fabric queue
> > > status: -22 [17066.397287] QP 3 flush_issued [17066.397287]
> > > i40iw_post_send: qp 3 wr_opcode 0 ret_err -22 [17066.397288] isert:
> > > isert_rdma_rw_ctx_post: Cmd: ffff8817fb8e9bf0 failed to post RDMA res
> > > [17066.397288] Got unknown fabric queue status: -22 [17066.397291] QP
> > > 3 flush_issued [17066.397292] i40iw_post_send: qp 3 wr_opcode 0
> > > ret_err -22 [17066.397292] isert: isert_rdma_rw_ctx_post: Cmd:
> > > ffff8817fb8ecc30 failed to post RDMA res [17066.397292] Got unknown
> > > fabric queue status: -22 [17066.397295] QP 3 flush_issued
> > > [17066.397296] i40iw_post_send: qp 3 wr_opcode 0 ret_err -22
> > > [17066.397296] isert: isert_rdma_rw_ctx_post: Cmd: ffff8817fb8f20a0
> > > failed to post RDMA res [17066.397297] Got unknown fabric queue
> > > status: -22 [17066.397307] QP 3 flush_issued [17066.397307]
> > > i40iw_post_send: qp 3 wr_opcode 8 ret_err -22 [17066.397308] isert:
> > > isert_post_response: ib_post_send failed with -22 [17066.397309] i40iw
> > > i40iw_qp_disconnect Call close API [....]
> > >
> > > Shiraz
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe
> > > target-devel" in the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the
> > body of a message to majordomo@vger.kernel.org More majordomo info at
> > http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Shiraz, Michal & Co,

Thanks for the feedback.  Comments below.

On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > Sent: Monday, January 15, 2018 6:57 AM
> > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > 
> > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > 
> > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > target queue-full memory leak:
> > > 
> > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > 
> > > Just curious how frequent this happens in practice with sustained large block
> > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > qedr and iw_cxgb4)..?
> > > 
> > > Is there anything else from an iser-target consumer level that should be
> > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > 
> > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > Issue when running RoCE. It's not iWARP related. 
> > This is easily reproduced within seconds with IO size of 5121K
> > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > 
> > IO Command used:
> > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > 
> > thanks,
> > Michal
> 
> Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> rather quickly, in a matter of seconds.
> 
> fio --rw=read --bs=2048k --numjobs=1 --iodepth=128 --runtime=30 --size=20g --loops=1 --ioengine=libaio 
> --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> 

A couple of thoughts.

First, would it be helpful to limit maximum payload size per I/O for
consumers based on number of iser-target sq hw sges..?

That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
maximum payload size per I/O being too large there is an existing
target_core_fabric_ops mechanism for limiting using SCSI residuals,
originally utilized by qla2xxx here:

target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8f9b565482c537821588444e09ff732c7d65ed6e

Note this patch also will return a smaller Block Limits VPD (0x86)
MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
automatically limit maximum outgoing payload transfer length, and avoid
SCSI residual logic.

As-is, iser-target doesn't a propagate max_data_sg_ents limit into
iscsi-target, but you can try testing with a smaller value to see if
it's useful.  Eg:

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
index 0ebc481..d8a4cc5 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
        .module                         = THIS_MODULE,
        .name                           = "iscsi",
        .node_acl_size                  = sizeof(struct iscsi_node_acl),
+       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
        .get_fabric_name                = iscsi_get_fabric_name,
        .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
        .tpg_get_tag                    = lio_tpg_get_tag,

Second, if the failures are not SCSI transfer length specific, another
option would be to limit the total command sequence number depth (CmdSN)
per session.

This is controlled at runtime by default_cmdsn_depth TPG attribute:

/sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/attrib/default_cmdsn_depth

and on per initiator context with cmdsn_depth NodeACL attribute:

/sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/acls/$ACL_IQN/cmdsn_depth

Note these default to 64, and can be changed at build time via
include/target/iscsi/iscsi_target_core.h:TA_DEFAULT_CMDSN_DEPTH.

That said, Sagi, any further comments as what else iser-target should be
doing to avoid repeated queue-fulls with limited hw sges..?

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Shiraz, Michal & Co,

Thanks for the feedback.  Comments below.

On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > Sent: Monday, January 15, 2018 6:57 AM
> > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > 
> > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > 
> > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > target queue-full memory leak:
> > > 
> > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > 
> > > Just curious how frequent this happens in practice with sustained large block
> > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > qedr and iw_cxgb4)..?
> > > 
> > > Is there anything else from an iser-target consumer level that should be
> > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > 
> > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > Issue when running RoCE. It's not iWARP related. 
> > This is easily reproduced within seconds with IO size of 5121K
> > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > 
> > IO Command used:
> > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > 
> > thanks,
> > Michal
> 
> Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> rather quickly, in a matter of seconds.
> 
> fio --rw=read --bs 48k --numjobs=1 --iodepth\x128 --runtime0 --size g --loops=1 --ioengine=libaio 
> --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> 

A couple of thoughts.

First, would it be helpful to limit maximum payload size per I/O for
consumers based on number of iser-target sq hw sges..?

That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
maximum payload size per I/O being too large there is an existing
target_core_fabric_ops mechanism for limiting using SCSI residuals,
originally utilized by qla2xxx here:

target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id¸9b565482c537821588444e09ff732c7d65ed6e

Note this patch also will return a smaller Block Limits VPD (0x86)
MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
automatically limit maximum outgoing payload transfer length, and avoid
SCSI residual logic.

As-is, iser-target doesn't a propagate max_data_sg_ents limit into
iscsi-target, but you can try testing with a smaller value to see if
it's useful.  Eg:

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
index 0ebc481..d8a4cc5 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
        .module                         = THIS_MODULE,
        .name                           = "iscsi",
        .node_acl_size                  = sizeof(struct iscsi_node_acl),
+       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
        .get_fabric_name                = iscsi_get_fabric_name,
        .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
        .tpg_get_tag                    = lio_tpg_get_tag,

Second, if the failures are not SCSI transfer length specific, another
option would be to limit the total command sequence number depth (CmdSN)
per session.

This is controlled at runtime by default_cmdsn_depth TPG attribute:

/sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/attrib/default_cmdsn_depth

and on per initiator context with cmdsn_depth NodeACL attribute:

/sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/acls/$ACL_IQN/cmdsn_depth

Note these default to 64, and can be changed at build time via
include/target/iscsi/iscsi_target_core.h:TA_DEFAULT_CMDSN_DEPTH.

That said, Sagi, any further comments as what else iser-target should be
doing to avoid repeated queue-fulls with limited hw sges..?

--
To unsubscribe from this list: send the line "unsubscribe target-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Potnuri Bharat Teja]

Hi Nicholas, 
thanks for the suggestions. Comments below.

On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger wrote:
> Hi Shiraz, Michal & Co,
> 
> Thanks for the feedback.  Comments below.
> 
> On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > 
> > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > 
> > > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > > target queue-full memory leak:
> > > > 
> > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > 
> > > > Just curious how frequent this happens in practice with sustained large block
> > > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > > qedr and iw_cxgb4)..?
> > > > 
> > > > Is there anything else from an iser-target consumer level that should be
> > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > 
> > > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > > Issue when running RoCE. It's not iWARP related. 
> > > This is easily reproduced within seconds with IO size of 5121K
> > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > > 
> > > IO Command used:
> > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > 
> > > thanks,
> > > Michal
> > 
> > Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> > rather quickly, in a matter of seconds.
> > 
> > fio --rw=read --bs=2048k --numjobs=1 --iodepth=128 --runtime=30 --size=20g --loops=1 --ioengine=libaio 
> > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> > 
> 
> A couple of thoughts.
> 
> First, would it be helpful to limit maximum payload size per I/O for
> consumers based on number of iser-target sq hw sges..?
yes, I think HW num sge needs to be propagated to iscsi target.
> 
> That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> maximum payload size per I/O being too large there is an existing

Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
256k and for READ tests only with chelsio(iw_cxgb4) adapters.
> target_core_fabric_ops mechanism for limiting using SCSI residuals,
> originally utilized by qla2xxx here:
> 
> target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8f9b565482c537821588444e09ff732c7d65ed6e
> 
> Note this patch also will return a smaller Block Limits VPD (0x86)
> MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
> means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
> automatically limit maximum outgoing payload transfer length, and avoid
> SCSI residual logic.
> 
> As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> iscsi-target, but you can try testing with a smaller value to see if
> it's useful.  Eg:
> 
> diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
> index 0ebc481..d8a4cc5 100644
> --- a/drivers/target/iscsi/iscsi_target_configfs.c
> +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
>         .module                         = THIS_MODULE,
>         .name                           = "iscsi",
>         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
>         .get_fabric_name                = iscsi_get_fabric_name,
>         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
>         .tpg_get_tag                    = lio_tpg_get_tag,
> 
With above change, SQ overflow isn't observed. I started of with max_data_sg_nents = 16.
> Second, if the failures are not SCSI transfer length specific, another
> option would be to limit the total command sequence number depth (CmdSN)
> per session.
> 
> This is controlled at runtime by default_cmdsn_depth TPG attribute:
> 
> /sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/attrib/default_cmdsn_depth
> 
> and on per initiator context with cmdsn_depth NodeACL attribute:
> 
> /sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/acls/$ACL_IQN/cmdsn_depth
> 
> Note these default to 64, and can be changed at build time via
> include/target/iscsi/iscsi_target_core.h:TA_DEFAULT_CMDSN_DEPTH.
> 
> That said, Sagi, any further comments as what else iser-target should be
> doing to avoid repeated queue-fulls with limited hw sges..?
> 

Re: SQ overflow seen running isert traffic with high block sizes

[Potnuri Bharat Teja]

Hi Nicholas, 
thanks for the suggestions. Comments below.

On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger wrote:
> Hi Shiraz, Michal & Co,
> 
> Thanks for the feedback.  Comments below.
> 
> On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > 
> > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > 
> > > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > > target queue-full memory leak:
> > > > 
> > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > 
> > > > Just curious how frequent this happens in practice with sustained large block
> > > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > > qedr and iw_cxgb4)..?
> > > > 
> > > > Is there anything else from an iser-target consumer level that should be
> > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > 
> > > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > > Issue when running RoCE. It's not iWARP related. 
> > > This is easily reproduced within seconds with IO size of 5121K
> > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > > 
> > > IO Command used:
> > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > 
> > > thanks,
> > > Michal
> > 
> > Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> > rather quickly, in a matter of seconds.
> > 
> > fio --rw=read --bs 48k --numjobs=1 --iodepth\x128 --runtime0 --size g --loops=1 --ioengine=libaio 
> > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> > 
> 
> A couple of thoughts.
> 
> First, would it be helpful to limit maximum payload size per I/O for
> consumers based on number of iser-target sq hw sges..?
yes, I think HW num sge needs to be propagated to iscsi target.
> 
> That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> maximum payload size per I/O being too large there is an existing

Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
256k and for READ tests only with chelsio(iw_cxgb4) adapters.
> target_core_fabric_ops mechanism for limiting using SCSI residuals,
> originally utilized by qla2xxx here:
> 
> target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id¸9b565482c537821588444e09ff732c7d65ed6e
> 
> Note this patch also will return a smaller Block Limits VPD (0x86)
> MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
> means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
> automatically limit maximum outgoing payload transfer length, and avoid
> SCSI residual logic.
> 
> As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> iscsi-target, but you can try testing with a smaller value to see if
> it's useful.  Eg:
> 
> diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
> index 0ebc481..d8a4cc5 100644
> --- a/drivers/target/iscsi/iscsi_target_configfs.c
> +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
>         .module                         = THIS_MODULE,
>         .name                           = "iscsi",
>         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
>         .get_fabric_name                = iscsi_get_fabric_name,
>         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
>         .tpg_get_tag                    = lio_tpg_get_tag,
> 
With above change, SQ overflow isn't observed. I started of with max_data_sg_nents = 16.
> Second, if the failures are not SCSI transfer length specific, another
> option would be to limit the total command sequence number depth (CmdSN)
> per session.
> 
> This is controlled at runtime by default_cmdsn_depth TPG attribute:
> 
> /sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/attrib/default_cmdsn_depth
> 
> and on per initiator context with cmdsn_depth NodeACL attribute:
> 
> /sys/kernel/config/target/iscsi/$TARGET_IQN/$TPG/acls/$ACL_IQN/cmdsn_depth
> 
> Note these default to 64, and can be changed at build time via
> include/target/iscsi/iscsi_target_core.h:TA_DEFAULT_CMDSN_DEPTH.
> 
> That said, Sagi, any further comments as what else iser-target should be
> doing to avoid repeated queue-fulls with limited hw sges..?
> 
--
To unsubscribe from this list: send the line "unsubscribe target-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Potnuri & Co,

On Thu, 2018-01-18 at 23:23 +0530, Potnuri Bharat Teja wrote:
> Hi Nicholas, 
> thanks for the suggestions. Comments below.
> 
> On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger wrote:
> > Hi Shiraz, Michal & Co,
> > 
> > Thanks for the feedback.  Comments below.
> > 
> > On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > > From: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-rdma-
> > > > > owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Nicholas A. Bellinger
> > > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > > To: Shiraz Saleem <shiraz.saleem-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > > > > Cc: Amrani, Ram <Ram.Amrani-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>; Sagi Grimberg
> > > > > <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Elior, Ariel
> > > > > <Ariel.Elior-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>; target-devel <target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>;
> > > > > Potnuri Bharat Teja <bharat-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
> > > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > > 
> > > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > > 
> > > > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > > > target queue-full memory leak:
> > > > > 
> > > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > > 
> > > > > Just curious how frequent this happens in practice with sustained large block
> > > > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > > > qedr and iw_cxgb4)..?
> > > > > 
> > > > > Is there anything else from an iser-target consumer level that should be
> > > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > > 
> > > > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > > > Issue when running RoCE. It's not iWARP related. 
> > > > This is easily reproduced within seconds with IO size of 5121K
> > > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > > > 
> > > > IO Command used:
> > > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > > 
> > > > thanks,
> > > > Michal
> > > 
> > > Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> > > rather quickly, in a matter of seconds.
> > > 
> > > fio --rw=read --bs=2048k --numjobs=1 --iodepth=128 --runtime=30 --size=20g --loops=1 --ioengine=libaio 
> > > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> > > 
> > 
> > A couple of thoughts.
> > 
> > First, would it be helpful to limit maximum payload size per I/O for
> > consumers based on number of iser-target sq hw sges..?
> yes, I think HW num sge needs to be propagated to iscsi target.
> > 
> > That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> > maximum payload size per I/O being too large there is an existing
> 
> Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
> 256k and for READ tests only with chelsio(iw_cxgb4) adapters.

Thanks for confirming.

> > target_core_fabric_ops mechanism for limiting using SCSI residuals,
> > originally utilized by qla2xxx here:
> > 
> > target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8f9b565482c537821588444e09ff732c7d65ed6e
> > 
> > Note this patch also will return a smaller Block Limits VPD (0x86)
> > MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
> > means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
> > automatically limit maximum outgoing payload transfer length, and avoid
> > SCSI residual logic.
> > 
> > As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> > iscsi-target, but you can try testing with a smaller value to see if
> > it's useful.  Eg:
> > 
> > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
> > index 0ebc481..d8a4cc5 100644
> > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
> >         .module                         = THIS_MODULE,
> >         .name                           = "iscsi",
> >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
> >         .get_fabric_name                = iscsi_get_fabric_name,
> >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> >         .tpg_get_tag                    = lio_tpg_get_tag,
> > 
> With above change, SQ overflow isn't observed. I started of with max_data_sg_nents = 16.

OK, so max_data_sg_nents=32 (MAXIMUM TRANSFER SIZE=128K with 4k pages)
avoids SQ overflow with iw_cxgb4.

What is iw_cxgb4 reporting to isert_create_cq():attr.cap.max_send_sge..?

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Potnuri & Co,

On Thu, 2018-01-18 at 23:23 +0530, Potnuri Bharat Teja wrote:
> Hi Nicholas, 
> thanks for the suggestions. Comments below.
> 
> On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger wrote:
> > Hi Shiraz, Michal & Co,
> > 
> > Thanks for the feedback.  Comments below.
> > 
> > On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > > 
> > > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > > 
> > > > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > > > target queue-full memory leak:
> > > > > 
> > > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > > 
> > > > > Just curious how frequent this happens in practice with sustained large block
> > > > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > > > qedr and iw_cxgb4)..?
> > > > > 
> > > > > Is there anything else from an iser-target consumer level that should be
> > > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > > 
> > > > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > > > Issue when running RoCE. It's not iWARP related. 
> > > > This is easily reproduced within seconds with IO size of 5121K
> > > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > > > 
> > > > IO Command used:
> > > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > > 
> > > > thanks,
> > > > Michal
> > > 
> > > Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> > > rather quickly, in a matter of seconds.
> > > 
> > > fio --rw=read --bs 48k --numjobs=1 --iodepth\x128 --runtime0 --size g --loops=1 --ioengine=libaio 
> > > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> > > 
> > 
> > A couple of thoughts.
> > 
> > First, would it be helpful to limit maximum payload size per I/O for
> > consumers based on number of iser-target sq hw sges..?
> yes, I think HW num sge needs to be propagated to iscsi target.
> > 
> > That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> > maximum payload size per I/O being too large there is an existing
> 
> Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
> 256k and for READ tests only with chelsio(iw_cxgb4) adapters.

Thanks for confirming.

> > target_core_fabric_ops mechanism for limiting using SCSI residuals,
> > originally utilized by qla2xxx here:
> > 
> > target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id¸9b565482c537821588444e09ff732c7d65ed6e
> > 
> > Note this patch also will return a smaller Block Limits VPD (0x86)
> > MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
> > means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
> > automatically limit maximum outgoing payload transfer length, and avoid
> > SCSI residual logic.
> > 
> > As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> > iscsi-target, but you can try testing with a smaller value to see if
> > it's useful.  Eg:
> > 
> > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
> > index 0ebc481..d8a4cc5 100644
> > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
> >         .module                         = THIS_MODULE,
> >         .name                           = "iscsi",
> >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
> >         .get_fabric_name                = iscsi_get_fabric_name,
> >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> >         .tpg_get_tag                    = lio_tpg_get_tag,
> > 
> With above change, SQ overflow isn't observed. I started of with max_data_sg_nents = 16.

OK, so max_data_sg_nents2 (MAXIMUM TRANSFER SIZE\x128K with 4k pages)
avoids SQ overflow with iw_cxgb4.

What is iw_cxgb4 reporting to isert_create_cq():attr.cap.max_send_sge..?

--
To unsubscribe from this list: send the line "unsubscribe target-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Potnuri Bharat Teja]

On Wednesday, January 01/24/18, 2018 at 12:55:17 +0530, Nicholas A. Bellinger wrote:
> Hi Potnuri & Co,
> 
> On Thu, 2018-01-18 at 23:23 +0530, Potnuri Bharat Teja wrote:
> > Hi Nicholas, 
> > thanks for the suggestions. Comments below.
> > 
> > On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger wrote:
> > > Hi Shiraz, Michal & Co,
> > > 
> > > Thanks for the feedback.  Comments below.
> > > 
> > > On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > > > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > > > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > > > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > > > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > > > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > > > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > > > 
> > > > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > > > 
> > > > > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > > > > target queue-full memory leak:
> > > > > > 
> > > > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > > > 
> > > > > > Just curious how frequent this happens in practice with sustained large block
> > > > > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > > > > qedr and iw_cxgb4)..?
> > > > > > 
> > > > > > Is there anything else from an iser-target consumer level that should be
> > > > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > > > 
> > > > > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > > > > Issue when running RoCE. It's not iWARP related. 
> > > > > This is easily reproduced within seconds with IO size of 5121K
> > > > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > > > > 
> > > > > IO Command used:
> > > > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > > > 
> > > > > thanks,
> > > > > Michal
> > > > 
> > > > Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> > > > rather quickly, in a matter of seconds.
> > > > 
> > > > fio --rw=read --bs=2048k --numjobs=1 --iodepth=128 --runtime=30 --size=20g --loops=1 --ioengine=libaio 
> > > > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> > > > 
> > > 
> > > A couple of thoughts.
> > > 
> > > First, would it be helpful to limit maximum payload size per I/O for
> > > consumers based on number of iser-target sq hw sges..?
> > yes, I think HW num sge needs to be propagated to iscsi target.
> > > 
> > > That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> > > maximum payload size per I/O being too large there is an existing
> > 
> > Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
> > 256k and for READ tests only with chelsio(iw_cxgb4) adapters.
> 
> Thanks for confirming.
> 
> > > target_core_fabric_ops mechanism for limiting using SCSI residuals,
> > > originally utilized by qla2xxx here:
> > > 
> > > target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8f9b565482c537821588444e09ff732c7d65ed6e
> > > 
> > > Note this patch also will return a smaller Block Limits VPD (0x86)
> > > MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
> > > means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
> > > automatically limit maximum outgoing payload transfer length, and avoid
> > > SCSI residual logic.
> > > 
> > > As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> > > iscsi-target, but you can try testing with a smaller value to see if
> > > it's useful.  Eg:
> > > 
> > > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
> > > index 0ebc481..d8a4cc5 100644
> > > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
> > >         .module                         = THIS_MODULE,
> > >         .name                           = "iscsi",
> > >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
> > >         .get_fabric_name                = iscsi_get_fabric_name,
> > >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> > >         .tpg_get_tag                    = lio_tpg_get_tag,
> > > 
> > With above change, SQ overflow isn't observed. I started of with max_data_sg_nents = 16.
> 
> OK, so max_data_sg_nents=32 (MAXIMUM TRANSFER SIZE=128K with 4k pages)
> avoids SQ overflow with iw_cxgb4.
> 
> What is iw_cxgb4 reporting to isert_create_cq():attr.cap.max_send_sge..?
max_send_sge is 4 for iw_cxgb4
 
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Potnuri Bharat Teja]

On Wednesday, January 01/24/18, 2018 at 12:55:17 +0530, Nicholas A. Bellinger wrote:
> Hi Potnuri & Co,
> 
> On Thu, 2018-01-18 at 23:23 +0530, Potnuri Bharat Teja wrote:
> > Hi Nicholas, 
> > thanks for the suggestions. Comments below.
> > 
> > On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger wrote:
> > > Hi Shiraz, Michal & Co,
> > > 
> > > Thanks for the feedback.  Comments below.
> > > 
> > > On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > > > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > > > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > > > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > > > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > > > > <Ariel.Elior@cavium.com>; target-devel <target-devel@vger.kernel.org>;
> > > > > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > > > 
> > > > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > > > 
> > > > > > Following up on this old thread, as it relates to Potnuri's recent fix for a iser-
> > > > > > target queue-full memory leak:
> > > > > > 
> > > > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > > > 
> > > > > > Just curious how frequent this happens in practice with sustained large block
> > > > > > workloads, as it appears to effect at least three different iwarp RNICS (i40iw,
> > > > > > qedr and iw_cxgb4)..?
> > > > > > 
> > > > > > Is there anything else from an iser-target consumer level that should be
> > > > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > > > 
> > > > > Would like to mention, that although we are an iWARP RNIC as well, we've hit this
> > > > > Issue when running RoCE. It's not iWARP related. 
> > > > > This is easily reproduced within seconds with IO size of 5121K
> > > > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks each.
> > > > > 
> > > > > IO Command used:
> > > > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > > > 
> > > > > thanks,
> > > > > Michal
> > > > 
> > > > Its seen with block size >= 2M on a single target 1 RAM disk config. And similar to Michals report;
> > > > rather quickly, in a matter of seconds.
> > > > 
> > > > fio --rw=read --bs 48k --numjobs=1 --iodepth\x128 --runtime0 --size g --loops=1 --ioengine=libaio 
> > > > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --filename=/dev/sdb --name=sdb 
> > > > 
> > > 
> > > A couple of thoughts.
> > > 
> > > First, would it be helpful to limit maximum payload size per I/O for
> > > consumers based on number of iser-target sq hw sges..?
> > yes, I think HW num sge needs to be propagated to iscsi target.
> > > 
> > > That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> > > maximum payload size per I/O being too large there is an existing
> > 
> > Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
> > 256k and for READ tests only with chelsio(iw_cxgb4) adapters.
> 
> Thanks for confirming.
> 
> > > target_core_fabric_ops mechanism for limiting using SCSI residuals,
> > > originally utilized by qla2xxx here:
> > > 
> > > target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id¸9b565482c537821588444e09ff732c7d65ed6e
> > > 
> > > Note this patch also will return a smaller Block Limits VPD (0x86)
> > > MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE, which
> > > means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH will
> > > automatically limit maximum outgoing payload transfer length, and avoid
> > > SCSI residual logic.
> > > 
> > > As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> > > iscsi-target, but you can try testing with a smaller value to see if
> > > it's useful.  Eg:
> > > 
> > > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configf
> > > index 0ebc481..d8a4cc5 100644
> > > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
> > >         .module                         = THIS_MODULE,
> > >         .name                           = "iscsi",
> > >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM TRANSFER LENGTH */
> > >         .get_fabric_name                = iscsi_get_fabric_name,
> > >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> > >         .tpg_get_tag                    = lio_tpg_get_tag,
> > > 
> > With above change, SQ overflow isn't observed. I started of with max_data_sg_nents = 16.
> 
> OK, so max_data_sg_nents2 (MAXIMUM TRANSFER SIZE\x128K with 4k pages)
> avoids SQ overflow with iw_cxgb4.
> 
> What is iw_cxgb4 reporting to isert_create_cq():attr.cap.max_send_sge..?
max_send_sge is 4 for iw_cxgb4
 
> --
> To unsubscribe from this list: send the line "unsubscribe target-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe target-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

RE: SQ overflow seen running isert traffic with high block sizes

[Steve Wise]

Hey all,

> 
> Hi Potnuri & Co,
> 
> On Thu, 2018-01-18 at 23:23 +0530, Potnuri Bharat Teja wrote:
> > Hi Nicholas,
> > thanks for the suggestions. Comments below.
> >
> > On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger
> wrote:
> > > Hi Shiraz, Michal & Co,
> > >
> > > Thanks for the feedback.  Comments below.
> > >
> > > On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > > > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > > > From: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-rdma-
> > > > > > owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Nicholas A. Bellinger
> > > > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > > > To: Shiraz Saleem <shiraz.saleem-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > > > > > Cc: Amrani, Ram <Ram.Amrani-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>; Sagi Grimberg
> > > > > > <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Elior, Ariel
> > > > > > <Ariel.Elior-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>; target-devel <target-
> devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>;
> > > > > > Potnuri Bharat Teja <bharat-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
> > > > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > > >
> > > > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > > >
> > > > > > Following up on this old thread, as it relates to Potnuri's recent fix for a
> iser-
> > > > > > target queue-full memory leak:
> > > > > >
> > > > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > > >
> > > > > > Just curious how frequent this happens in practice with sustained large
> block
> > > > > > workloads, as it appears to effect at least three different iwarp RNICS
> (i40iw,
> > > > > > qedr and iw_cxgb4)..?
> > > > > >
> > > > > > Is there anything else from an iser-target consumer level that should be
> > > > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > > >
> > > > > Would like to mention, that although we are an iWARP RNIC as well,
> we've hit this
> > > > > Issue when running RoCE. It's not iWARP related.
> > > > > This is easily reproduced within seconds with IO size of 5121K
> > > > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks
> each.
> > > > >
> > > > > IO Command used:
> > > > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > > >
> > > > > thanks,
> > > > > Michal
> > > >
> > > > Its seen with block size >= 2M on a single target 1 RAM disk config. And
> similar to Michals report;
> > > > rather quickly, in a matter of seconds.
> > > >
> > > > fio --rw=read --bs=2048k --numjobs=1 --iodepth=128 --runtime=30 --
> size=20g --loops=1 --ioengine=libaio
> > > > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --
> filename=/dev/sdb --name=sdb
> > > >
> > >
> > > A couple of thoughts.
> > >
> > > First, would it be helpful to limit maximum payload size per I/O for
> > > consumers based on number of iser-target sq hw sges..?
> > yes, I think HW num sge needs to be propagated to iscsi target.
> > >
> > > That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> > > maximum payload size per I/O being too large there is an existing
> >
> > Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
> > 256k and for READ tests only with chelsio(iw_cxgb4) adapters.
> 
> Thanks for confirming.
> 
> > > target_core_fabric_ops mechanism for limiting using SCSI residuals,
> > > originally utilized by qla2xxx here:
> > >
> > > target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> > >
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8
> f9b565482c537821588444e09ff732c7d65ed6e
> > >
> > > Note this patch also will return a smaller Block Limits VPD (0x86)
> > > MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE,
> which
> > > means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH
> will
> > > automatically limit maximum outgoing payload transfer length, and avoid
> > > SCSI residual logic.
> > >
> > > As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> > > iscsi-target, but you can try testing with a smaller value to see if
> > > it's useful.  Eg:
> > >
> > > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
> b/drivers/target/iscsi/iscsi_target_configf
> > > index 0ebc481..d8a4cc5 100644
> > > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd
> *se_cmd)
> > >         .module                         = THIS_MODULE,
> > >         .name                           = "iscsi",
> > >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
> TRANSFER LENGTH */
> > >         .get_fabric_name                = iscsi_get_fabric_name,
> > >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> > >         .tpg_get_tag                    = lio_tpg_get_tag,
> > >
> > With above change, SQ overflow isn't observed. I started of with
> max_data_sg_nents = 16.
> 
> OK, so max_data_sg_nents=32 (MAXIMUM TRANSFER SIZE=128K with 4k pages)
> avoids SQ overflow with iw_cxgb4.
> 
> What is iw_cxgb4 reporting to isert_create_cq():attr.cap.max_send_sge..?

The ib_device attributes only advertise max_sge, which applies to both send and recv queues.  Because the iw_cxgb4 RQ max sge is 4, iw_cxgb4 currently advertises 4 for max_sge, even though the SQ can handle more.  So attr.cap.max_send_sge ends up being 4.

I have a todo on my list to extend the rdma/core to have max_send_sge and max_recv_sge attributes.  If it helps, I can bump up the priority of this.  Perhaps Bharat could do the work.

Steve.

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

RE: SQ overflow seen running isert traffic with high block sizes

[Steve Wise]

Hey all,

> 
> Hi Potnuri & Co,
> 
> On Thu, 2018-01-18 at 23:23 +0530, Potnuri Bharat Teja wrote:
> > Hi Nicholas,
> > thanks for the suggestions. Comments below.
> >
> > On Thursday, January 01/18/18, 2018 at 15:28:42 +0530, Nicholas A. Bellinger
> wrote:
> > > Hi Shiraz, Michal & Co,
> > >
> > > Thanks for the feedback.  Comments below.
> > >
> > > On Mon, 2018-01-15 at 09:22 -0600, Shiraz Saleem wrote:
> > > > On Mon, Jan 15, 2018 at 03:12:36AM -0700, Kalderon, Michal wrote:
> > > > > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > > > > > owner@vger.kernel.org] On Behalf Of Nicholas A. Bellinger
> > > > > > Sent: Monday, January 15, 2018 6:57 AM
> > > > > > To: Shiraz Saleem <shiraz.saleem@intel.com>
> > > > > > Cc: Amrani, Ram <Ram.Amrani@cavium.com>; Sagi Grimberg
> > > > > > <sagi@grimberg.me>; linux-rdma@vger.kernel.org; Elior, Ariel
> > > > > > <Ariel.Elior@cavium.com>; target-devel <target-
> devel@vger.kernel.org>;
> > > > > > Potnuri Bharat Teja <bharat@chelsio.com>
> > > > > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > > > >
> > > > > > Hi Shiraz, Ram, Ariel, & Potnuri,
> > > > > >
> > > > > > Following up on this old thread, as it relates to Potnuri's recent fix for a
> iser-
> > > > > > target queue-full memory leak:
> > > > > >
> > > > > > https://www.spinics.net/lists/target-devel/msg16282.html
> > > > > >
> > > > > > Just curious how frequent this happens in practice with sustained large
> block
> > > > > > workloads, as it appears to effect at least three different iwarp RNICS
> (i40iw,
> > > > > > qedr and iw_cxgb4)..?
> > > > > >
> > > > > > Is there anything else from an iser-target consumer level that should be
> > > > > > changed for iwarp to avoid repeated ib_post_send() failures..?
> > > > > >
> > > > > Would like to mention, that although we are an iWARP RNIC as well,
> we've hit this
> > > > > Issue when running RoCE. It's not iWARP related.
> > > > > This is easily reproduced within seconds with IO size of 5121K
> > > > > Using 5 Targets with 2 Ram Disk each and 5 targets with FileIO Disks
> each.
> > > > >
> > > > > IO Command used:
> > > > > maim -b512k -T32 -t2 -Q8 -M0 -o -u -n -m17 -ftargets.dat -d1
> > > > >
> > > > > thanks,
> > > > > Michal
> > > >
> > > > Its seen with block size >= 2M on a single target 1 RAM disk config. And
> similar to Michals report;
> > > > rather quickly, in a matter of seconds.
> > > >
> > > > fio --rw=read --bs 48k --numjobs=1 --iodepth\x128 --runtime0 --
> size g --loops=1 --ioengine=libaio
> > > > --direct=1 --invalidate=1 --fsync_on_close=1 --norandommap --exitall --
> filename=/dev/sdb --name=sdb
> > > >
> > >
> > > A couple of thoughts.
> > >
> > > First, would it be helpful to limit maximum payload size per I/O for
> > > consumers based on number of iser-target sq hw sges..?
> > yes, I think HW num sge needs to be propagated to iscsi target.
> > >
> > > That is, if rdma_rw_ctx_post() -> ib_post_send() failures are related to
> > > maximum payload size per I/O being too large there is an existing
> >
> > Yes they are IO size specific, I observed SQ overflow with fio for IO sizes above
> > 256k and for READ tests only with chelsio(iw_cxgb4) adapters.
> 
> Thanks for confirming.
> 
> > > target_core_fabric_ops mechanism for limiting using SCSI residuals,
> > > originally utilized by qla2xxx here:
> > >
> > > target/qla2xxx: Honor max_data_sg_nents I/O transfer limit
> > >
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8
> f9b565482c537821588444e09ff732c7d65ed6e
> > >
> > > Note this patch also will return a smaller Block Limits VPD (0x86)
> > > MAXIMUM TRANSFER LENGTH based on max_data_sg_nents * PAGE_SIZE,
> which
> > > means for modern SCSI initiators honoring MAXIMUM TRANSFER LENGTH
> will
> > > automatically limit maximum outgoing payload transfer length, and avoid
> > > SCSI residual logic.
> > >
> > > As-is, iser-target doesn't a propagate max_data_sg_ents limit into
> > > iscsi-target, but you can try testing with a smaller value to see if
> > > it's useful.  Eg:
> > >
> > > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
> b/drivers/target/iscsi/iscsi_target_configf
> > > index 0ebc481..d8a4cc5 100644
> > > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd
> *se_cmd)
> > >         .module                         = THIS_MODULE,
> > >         .name                           = "iscsi",
> > >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
> TRANSFER LENGTH */
> > >         .get_fabric_name                = iscsi_get_fabric_name,
> > >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> > >         .tpg_get_tag                    = lio_tpg_get_tag,
> > >
> > With above change, SQ overflow isn't observed. I started of with
> max_data_sg_nents = 16.
> 
> OK, so max_data_sg_nents2 (MAXIMUM TRANSFER SIZE\x128K with 4k pages)
> avoids SQ overflow with iw_cxgb4.
> 
> What is iw_cxgb4 reporting to isert_create_cq():attr.cap.max_send_sge..?

The ib_device attributes only advertise max_sge, which applies to both send and recv queues.  Because the iw_cxgb4 RQ max sge is 4, iw_cxgb4 currently advertises 4 for max_sge, even though the SQ can handle more.  So attr.cap.max_send_sge ends up being 4.

I have a todo on my list to extend the rdma/core to have max_send_sge and max_recv_sge attributes.  If it helps, I can bump up the priority of this.  Perhaps Bharat could do the work.

Steve.

Re: SQ overflow seen running isert traffic with high block sizes

[Kalderon, Michal]

________________________________________
From: Nicholas A. Bellinger <nab@linux-iscsi.org>
Sent: Thursday, January 18, 2018 11:58 AM

> Hi Shiraz, Michal & Co,
Hi Nicholas, 

> Thanks for the feedback.  Comments below.

> A couple of thoughts.

> First, would it be helpful to limit maximum payload size per I/O for
> consumers based on number of iser-target sq hw sges..?

I don't think you need to limit the maximum payload, but instead 
initialize the max_wr to be based on the number of supported SGEs
Instead of what is there today:
#define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
                                ISERT_MAX_TX_MISC_PDUS  + \
                                ISERT_MAX_RX_MISC_PDUS)
Add the maximum number of WQEs per command, 
The calculation of number of WQEs per command needs to be something like
"MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".

For some devices like ours, breaking the IO into multiple WRs according to supported
number of SGEs doesn't necessarily means performance penalty.

thanks,
Michal

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Michal & Co,

On Fri, 2018-01-19 at 19:33 +0000, Kalderon, Michal wrote:
> ________________________________________
> From: Nicholas A. Bellinger <nab@linux-iscsi.org>
> Sent: Thursday, January 18, 2018 11:58 AM
> 
> > Hi Shiraz, Michal & Co,
> Hi Nicholas, 
> 
> > Thanks for the feedback.  Comments below.
> 
> > A couple of thoughts.
> 
> > First, would it be helpful to limit maximum payload size per I/O for
> > consumers based on number of iser-target sq hw sges..?
> 
> I don't think you need to limit the maximum payload, but instead 
> initialize the max_wr to be based on the number of supported SGEs
> Instead of what is there today:
> #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
>                                 ISERT_MAX_TX_MISC_PDUS  + \
>                                 ISERT_MAX_RX_MISC_PDUS)
> Add the maximum number of WQEs per command, 
> The calculation of number of WQEs per command needs to be something like
> "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
> 

Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
right..?

Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
ISER_MAX_CQ_LEN, which currently depend on ISERT_QP_MAX_REQ_DTOS..

Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at
runtime vs. exposing a smaller max_data_sg_nents=32 for ib_devices with
limited attr.cap.max_send_sge..?

> For some devices like ours, breaking the IO into multiple WRs according to supported
> number of SGEs doesn't necessarily means performance penalty.
> 

AFAICT ading max_data_sg_nents for iser-target is safe enough
work-around to include for stable, assuming we agree on what the
max_send_sg cut-off is for setting max_data_sg_nents=32 usage from a
larger default.  I don't have a string preference either way, as long as
it can be picked up for 4.x stable.

Sagi, WDYT..?

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Michal & Co,

On Fri, 2018-01-19 at 19:33 +0000, Kalderon, Michal wrote:
> ________________________________________
> From: Nicholas A. Bellinger <nab@linux-iscsi.org>
> Sent: Thursday, January 18, 2018 11:58 AM
> 
> > Hi Shiraz, Michal & Co,
> Hi Nicholas, 
> 
> > Thanks for the feedback.  Comments below.
> 
> > A couple of thoughts.
> 
> > First, would it be helpful to limit maximum payload size per I/O for
> > consumers based on number of iser-target sq hw sges..?
> 
> I don't think you need to limit the maximum payload, but instead 
> initialize the max_wr to be based on the number of supported SGEs
> Instead of what is there today:
> #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
>                                 ISERT_MAX_TX_MISC_PDUS  + \
>                                 ISERT_MAX_RX_MISC_PDUS)
> Add the maximum number of WQEs per command, 
> The calculation of number of WQEs per command needs to be something like
> "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
> 

Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
right..?

Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
ISER_MAX_CQ_LEN, which currently depend on ISERT_QP_MAX_REQ_DTOS..

Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at
runtime vs. exposing a smaller max_data_sg_nents2 for ib_devices with
limited attr.cap.max_send_sge..?

> For some devices like ours, breaking the IO into multiple WRs according to supported
> number of SGEs doesn't necessarily means performance penalty.
> 

AFAICT ading max_data_sg_nents for iser-target is safe enough
work-around to include for stable, assuming we agree on what the
max_send_sg cut-off is for setting max_data_sg_nents2 usage from a
larger default.  I don't have a string preference either way, as long as
it can be picked up for 4.x stable.

Sagi, WDYT..?

RE: SQ overflow seen running isert traffic with high block sizes

[Kalderon, Michal]

> From: Nicholas A. Bellinger [mailto:nab@linux-iscsi.org]
> Sent: Wednesday, January 24, 2018 9:56 AM
> 
> Hi Michal & Co,
> 
> On Fri, 2018-01-19 at 19:33 +0000, Kalderon, Michal wrote:
> > ________________________________________
> > From: Nicholas A. Bellinger <nab@linux-iscsi.org>
> > Sent: Thursday, January 18, 2018 11:58 AM
> >
> > > Hi Shiraz, Michal & Co,
> > Hi Nicholas,
> >
> > > Thanks for the feedback.  Comments below.
> >
> > > A couple of thoughts.
> >
> > > First, would it be helpful to limit maximum payload size per I/O for
> > > consumers based on number of iser-target sq hw sges..?
> >
> > I don't think you need to limit the maximum payload, but instead
> > initialize the max_wr to be based on the number of supported SGEs
> > Instead of what is there today:
> > #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
> >                                 ISERT_MAX_TX_MISC_PDUS  + \
> >                                 ISERT_MAX_RX_MISC_PDUS) Add the
> > maximum number of WQEs per command, The calculation of number of
> WQEs
> > per command needs to be something like
> > "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
> >
> 
> Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
> right..?
Globally or perhaps configurable by sysfs configuration?
> 
> Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
> ISER_MAX_CQ_LEN, which currently depend on
> ISERT_QP_MAX_REQ_DTOS..
I think it can remain dependent on MAX_REQ_DTOS. 
> 
> Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at runtime
> vs. exposing a smaller max_data_sg_nents=32 for ib_devices with limited
> attr.cap.max_send_sge..?
For our device defining max_data_sg_nents didn't help on some scenarios,
It seems that Frequency of the issue occurring increases with number of luns we
Try to run over. 

> 
> > For some devices like ours, breaking the IO into multiple WRs
> > according to supported number of SGEs doesn't necessarily means
> performance penalty.
> >
> 
> AFAICT ading max_data_sg_nents for iser-target is safe enough work-around
> to include for stable, assuming we agree on what the max_send_sg cut-off is
> for setting max_data_sg_nents=32 usage from a larger default.  I don't have
> a string preference either way, as long as it can be picked up for 4.x stable.
> 
> Sagi, WDYT..?

RE: SQ overflow seen running isert traffic with high block sizes

[Kalderon, Michal]
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Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

>> Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at runtime
>> vs. exposing a smaller max_data_sg_nents=32 for ib_devices with limited
>> attr.cap.max_send_sge..?
> For our device defining max_data_sg_nents didn't help on some scenarios,
> It seems that Frequency of the issue occurring increases with number of luns we
> Try to run over.

Maybe this is related to the queue-full strategy the target core takes
by simply scheduling another attempt unconditionally without any
hard guarantees that the next attempt will succeed?

This flow is per se_device which might be a hint why its happening more
with a larger number of luns? maybe the isert completion handler
context (which is also workqueue) struggles with finding cpu quota?

Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

>> Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at runtime
>> vs. exposing a smaller max_data_sg_nents2 for ib_devices with limited
>> attr.cap.max_send_sge..?
> For our device defining max_data_sg_nents didn't help on some scenarios,
> It seems that Frequency of the issue occurring increases with number of luns we
> Try to run over.

Maybe this is related to the queue-full strategy the target core takes
by simply scheduling another attempt unconditionally without any
hard guarantees that the next attempt will succeed?

This flow is per se_device which might be a hint why its happening more
with a larger number of luns? maybe the isert completion handler
context (which is also workqueue) struggles with finding cpu quota?

Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

>>> First, would it be helpful to limit maximum payload size per I/O for
>>> consumers based on number of iser-target sq hw sges..?
>>
>> I don't think you need to limit the maximum payload, but instead
>> initialize the max_wr to be based on the number of supported SGEs
>> Instead of what is there today:
>> #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
>>                                  ISERT_MAX_TX_MISC_PDUS  + \
>>                                  ISERT_MAX_RX_MISC_PDUS)
>> Add the maximum number of WQEs per command,
>> The calculation of number of WQEs per command needs to be something like
>> "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
>>
> 
> Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
> right..?
> 
> Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
> ISER_MAX_CQ_LEN, which currently depend on ISERT_QP_MAX_REQ_DTOS..
> 
> Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at
> runtime vs. exposing a smaller max_data_sg_nents=32 for ib_devices with
> limited attr.cap.max_send_sge..?

Sorry for the late reply,

Can we go back and understand why do we need to limit isert transfer
size? I would suggest that we handle queue-full scenarios instead
of limiting the transfered payload size.

 From the trace Shiraz sent, it looks that:
a) we are too chatty when failing to post a wr on a queue-pair
(something that can happen by design), and
b) isert escalates to terminating the connection which means we
screwed up handling it.

Shiraz, can you explain these messages:
[17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
[17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3

Who is initiating the connection teardown? the initiator or the target?
(looks like the initiator gave up on iscsi ping timeout expiration)

Nic,
Currently, what I see is that queue-full handler simply schedules qf
work to re-issue the I/O again. The issue is that the only way that
a new send queue entry becomes available again is that isert process
one or more send completions. If at all, this work is interfering with
the isert_send_done handler.

Will it be possible that some transports will be able to schedule
qf_work_queue themselves? I guess It would also hold if iscsit were to
use non-blocking sockets and continue at .write_space()?

Something like transport_process_wait_list() that would be triggered
from the transport completion handler (or from centralize place like
target_sess_put_cmd or something...)?

Also, I see that this wait list is singular accross the se_device. Maybe
it would be a better idea to have it per se_session as it maps to iscsi
connection (or srp channel for that matter)? For large I/O sizes this
should happen quite a lot so its a bit of a shame that we need will
to compete over the list_empty check...

If we prefer to make this go away by limiting the transfer size then its
fine I guess, but maybe we can do better? (although it can take some
extra work...)

>> For some devices like ours, breaking the IO into multiple WRs according to supported
>> number of SGEs doesn't necessarily means performance penalty.
>>
> 
> AFAICT ading max_data_sg_nents for iser-target is safe enough
> work-around to include for stable, assuming we agree on what the
> max_send_sg cut-off is for setting max_data_sg_nents=32 usage from a
> larger default.  I don't have a string preference either way, as long as
> it can be picked up for 4.x stable. >
> Sagi, WDYT..?

I think its an easier fix for sure. What I don't know, is weather this
introduces a regression for devices that can handle more sges on large
I/O sizes. I very much doubt it will though...
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

>>> First, would it be helpful to limit maximum payload size per I/O for
>>> consumers based on number of iser-target sq hw sges..?
>>
>> I don't think you need to limit the maximum payload, but instead
>> initialize the max_wr to be based on the number of supported SGEs
>> Instead of what is there today:
>> #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
>>                                  ISERT_MAX_TX_MISC_PDUS  + \
>>                                  ISERT_MAX_RX_MISC_PDUS)
>> Add the maximum number of WQEs per command,
>> The calculation of number of WQEs per command needs to be something like
>> "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
>>
> 
> Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
> right..?
> 
> Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
> ISER_MAX_CQ_LEN, which currently depend on ISERT_QP_MAX_REQ_DTOS..
> 
> Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at
> runtime vs. exposing a smaller max_data_sg_nents2 for ib_devices with
> limited attr.cap.max_send_sge..?

Sorry for the late reply,

Can we go back and understand why do we need to limit isert transfer
size? I would suggest that we handle queue-full scenarios instead
of limiting the transfered payload size.

 From the trace Shiraz sent, it looks that:
a) we are too chatty when failing to post a wr on a queue-pair
(something that can happen by design), and
b) isert escalates to terminating the connection which means we
screwed up handling it.

Shiraz, can you explain these messages:
[17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
[17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3

Who is initiating the connection teardown? the initiator or the target?
(looks like the initiator gave up on iscsi ping timeout expiration)

Nic,
Currently, what I see is that queue-full handler simply schedules qf
work to re-issue the I/O again. The issue is that the only way that
a new send queue entry becomes available again is that isert process
one or more send completions. If at all, this work is interfering with
the isert_send_done handler.

Will it be possible that some transports will be able to schedule
qf_work_queue themselves? I guess It would also hold if iscsit were to
use non-blocking sockets and continue at .write_space()?

Something like transport_process_wait_list() that would be triggered
from the transport completion handler (or from centralize place like
target_sess_put_cmd or something...)?

Also, I see that this wait list is singular accross the se_device. Maybe
it would be a better idea to have it per se_session as it maps to iscsi
connection (or srp channel for that matter)? For large I/O sizes this
should happen quite a lot so its a bit of a shame that we need will
to compete over the list_empty check...

If we prefer to make this go away by limiting the transfer size then its
fine I guess, but maybe we can do better? (although it can take some
extra work...)

>> For some devices like ours, breaking the IO into multiple WRs according to supported
>> number of SGEs doesn't necessarily means performance penalty.
>>
> 
> AFAICT ading max_data_sg_nents for iser-target is safe enough
> work-around to include for stable, assuming we agree on what the
> max_send_sg cut-off is for setting max_data_sg_nents2 usage from a
> larger default.  I don't have a string preference either way, as long as
> it can be picked up for 4.x stable. >
> Sagi, WDYT..?

I think its an easier fix for sure. What I don't know, is weather this
introduces a regression for devices that can handle more sges on large
I/O sizes. I very much doubt it will though...

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Mon, Jan 29, 2018 at 09:17:02PM +0200, Sagi Grimberg wrote:
> 
> > > > First, would it be helpful to limit maximum payload size per I/O for
> > > > consumers based on number of iser-target sq hw sges..?
> > > 
> > > I don't think you need to limit the maximum payload, but instead
> > > initialize the max_wr to be based on the number of supported SGEs
> > > Instead of what is there today:
> > > #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
> > >                                  ISERT_MAX_TX_MISC_PDUS  + \
> > >                                  ISERT_MAX_RX_MISC_PDUS)
> > > Add the maximum number of WQEs per command,
> > > The calculation of number of WQEs per command needs to be something like
> > > "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
> > > 
> > 
> > Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
> > right..?
> > 
> > Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
> > ISER_MAX_CQ_LEN, which currently depend on ISERT_QP_MAX_REQ_DTOS..
> > 
> > Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at
> > runtime vs. exposing a smaller max_data_sg_nents=32 for ib_devices with
> > limited attr.cap.max_send_sge..?
> 
> Sorry for the late reply,
> 
> Can we go back and understand why do we need to limit isert transfer
> size? I would suggest that we handle queue-full scenarios instead
> of limiting the transfered payload size.
> 
> From the trace Shiraz sent, it looks that:
> a) we are too chatty when failing to post a wr on a queue-pair
> (something that can happen by design), and
> b) isert escalates to terminating the connection which means we
> screwed up handling it.
> 
> Shiraz, can you explain these messages:
> [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
> [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3

These are some device specific Asynchronous Event logging I turned on.
It indicates the QP received a FIN while in RTS and eventually was moved
to CLOSED state.

 
> Who is initiating the connection teardown? the initiator or the target?
> (looks like the initiator gave up on iscsi ping timeout expiration)
> 

Initiator

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Mon, Jan 29, 2018 at 09:17:02PM +0200, Sagi Grimberg wrote:
> 
> > > > First, would it be helpful to limit maximum payload size per I/O for
> > > > consumers based on number of iser-target sq hw sges..?
> > > 
> > > I don't think you need to limit the maximum payload, but instead
> > > initialize the max_wr to be based on the number of supported SGEs
> > > Instead of what is there today:
> > > #define ISERT_QP_MAX_REQ_DTOS   (ISCSI_DEF_XMIT_CMDS_MAX +    \
> > >                                  ISERT_MAX_TX_MISC_PDUS  + \
> > >                                  ISERT_MAX_RX_MISC_PDUS)
> > > Add the maximum number of WQEs per command,
> > > The calculation of number of WQEs per command needs to be something like
> > > "MAX_TRANSFER_SIZE/(numSges*PAGE_SIZE)".
> > > 
> > 
> > Makes sense, MAX_TRANSFER_SIZE would be defined globally by iser-target,
> > right..?
> > 
> > Btw, I'm not sure how this effects usage of ISER_MAX_TX_CQ_LEN +
> > ISER_MAX_CQ_LEN, which currently depend on ISERT_QP_MAX_REQ_DTOS..
> > 
> > Sagi, what are your thoughts wrt changing attr.cap.max_send_wr at
> > runtime vs. exposing a smaller max_data_sg_nents2 for ib_devices with
> > limited attr.cap.max_send_sge..?
> 
> Sorry for the late reply,
> 
> Can we go back and understand why do we need to limit isert transfer
> size? I would suggest that we handle queue-full scenarios instead
> of limiting the transfered payload size.
> 
> From the trace Shiraz sent, it looks that:
> a) we are too chatty when failing to post a wr on a queue-pair
> (something that can happen by design), and
> b) isert escalates to terminating the connection which means we
> screwed up handling it.
> 
> Shiraz, can you explain these messages:
> [17066.397206] i40iw i40iw_process_aeq ae_id = 0x503 bool qp=1 qp_id = 3
> [17066.397247] i40iw i40iw_process_aeq ae_id = 0x501 bool qp=1 qp_id = 3

These are some device specific Asynchronous Event logging I turned on.
It indicates the QP received a FIN while in RTS and eventually was moved
to CLOSED state.

 
> Who is initiating the connection teardown? the initiator or the target?
> (looks like the initiator gave up on iscsi ping timeout expiration)
> 

Initiator

RE: SQ overflow seen running isert traffic with high block sizes

[Saleem, Shiraz]

> Subject: Re: SQ overflow seen running isert traffic with high block sizes
> 
> 
> First, would it be helpful to limit maximum payload size per I/O for consumers
> based on number of iser-target sq hw sges..?
> 
Assuming data is not able to be fast registered as if virtually contiguous;
artificially limiting the data size might not be the best solution.

But max SGEs does need to be exposed higher. Somewhere in the stack,
there might need to be multiple WRs submitted or data copied.

> diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
> b/drivers/target/iscsi/iscsi_target_configf
> index 0ebc481..d8a4cc5 100644
> --- a/drivers/target/iscsi/iscsi_target_configfs.c
> +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
>         .module                         = THIS_MODULE,
>         .name                           = "iscsi",
>         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
> TRANSFER LENGTH */
>         .get_fabric_name                = iscsi_get_fabric_name,
>         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
>         .tpg_get_tag                    = lio_tpg_get_tag,
> 

BTW, this is helping the SQ overflow issue.

RE: SQ overflow seen running isert traffic with high block sizes

[Saleem, Shiraz]
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=

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Shiraz & Co,

Thanks for the feedback.

On Mon, 2018-01-22 at 17:49 +0000, Saleem, Shiraz wrote:
> > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > 
> > 
> > First, would it be helpful to limit maximum payload size per I/O for consumers
> > based on number of iser-target sq hw sges..?
> > 
> Assuming data is not able to be fast registered as if virtually contiguous;
> artificially limiting the data size might not be the best solution.
> 
> But max SGEs does need to be exposed higher. Somewhere in the stack,
> there might need to be multiple WRs submitted or data copied.
> 

Sagi..?

> > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
> > b/drivers/target/iscsi/iscsi_target_configf
> > index 0ebc481..d8a4cc5 100644
> > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
> >         .module                         = THIS_MODULE,
> >         .name                           = "iscsi",
> >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
> > TRANSFER LENGTH */
> >         .get_fabric_name                = iscsi_get_fabric_name,
> >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> >         .tpg_get_tag                    = lio_tpg_get_tag,
> > 
> 
> BTW, this is helping the SQ overflow issue.

Thanks for confirming as a possible work-around.

For reference, what is i40iw's max_send_sg reporting..?

Is max_data_sg_nents=32 + 4k pages = 128K the largest MAX TRANSFER
LENGTH to avoid consistent SQ overflow as-is with i40iw..?

Re: SQ overflow seen running isert traffic with high block sizes

[Nicholas A. Bellinger]

Hi Shiraz & Co,

Thanks for the feedback.

On Mon, 2018-01-22 at 17:49 +0000, Saleem, Shiraz wrote:
> > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > 
> > 
> > First, would it be helpful to limit maximum payload size per I/O for consumers
> > based on number of iser-target sq hw sges..?
> > 
> Assuming data is not able to be fast registered as if virtually contiguous;
> artificially limiting the data size might not be the best solution.
> 
> But max SGEs does need to be exposed higher. Somewhere in the stack,
> there might need to be multiple WRs submitted or data copied.
> 

Sagi..?

> > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
> > b/drivers/target/iscsi/iscsi_target_configf
> > index 0ebc481..d8a4cc5 100644
> > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
> >         .module                         = THIS_MODULE,
> >         .name                           = "iscsi",
> >         .node_acl_size                  = sizeof(struct iscsi_node_acl),
> > +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
> > TRANSFER LENGTH */
> >         .get_fabric_name                = iscsi_get_fabric_name,
> >         .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
> >         .tpg_get_tag                    = lio_tpg_get_tag,
> > 
> 
> BTW, this is helping the SQ overflow issue.

Thanks for confirming as a possible work-around.

For reference, what is i40iw's max_send_sg reporting..?

Is max_data_sg_nents2 + 4k pages = 128K the largest MAX TRANSFER
LENGTH to avoid consistent SQ overflow as-is with i40iw..?

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Wed, Jan 24, 2018 at 01:01:58AM -0700, Nicholas A. Bellinger wrote:
> Hi Shiraz & Co,
> 
> Thanks for the feedback.
> 
> On Mon, 2018-01-22 at 17:49 +0000, Saleem, Shiraz wrote:
> > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > 
> > > 
> > > First, would it be helpful to limit maximum payload size per I/O for consumers
> > > based on number of iser-target sq hw sges..?
> > > 
> > Assuming data is not able to be fast registered as if virtually contiguous;
> > artificially limiting the data size might not be the best solution.
> > 
> > But max SGEs does need to be exposed higher. Somewhere in the stack,
> > there might need to be multiple WRs submitted or data copied.
> > 
> 
> Sagi..?
> 

> 
> For reference, what is i40iw's max_send_sg reporting..?

3

> 
> Is max_data_sg_nents=32 + 4k pages = 128K the largest MAX TRANSFER
> LENGTH to avoid consistent SQ overflow as-is with i40iw..?

For the configuration I am testing, max_data_sg_nents=32 & 64 worked,
and the SQ overflow issue reproduced at 128.

Re: SQ overflow seen running isert traffic with high block sizes

[Shiraz Saleem]

On Wed, Jan 24, 2018 at 01:01:58AM -0700, Nicholas A. Bellinger wrote:
> Hi Shiraz & Co,
> 
> Thanks for the feedback.
> 
> On Mon, 2018-01-22 at 17:49 +0000, Saleem, Shiraz wrote:
> > > Subject: Re: SQ overflow seen running isert traffic with high block sizes
> > > 
> > > 
> > > First, would it be helpful to limit maximum payload size per I/O for consumers
> > > based on number of iser-target sq hw sges..?
> > > 
> > Assuming data is not able to be fast registered as if virtually contiguous;
> > artificially limiting the data size might not be the best solution.
> > 
> > But max SGEs does need to be exposed higher. Somewhere in the stack,
> > there might need to be multiple WRs submitted or data copied.
> > 
> 
> Sagi..?
> 

> 
> For reference, what is i40iw's max_send_sg reporting..?

3

> 
> Is max_data_sg_nents2 + 4k pages = 128K the largest MAX TRANSFER
> LENGTH to avoid consistent SQ overflow as-is with i40iw..?

For the configuration I am testing, max_data_sg_nents2 & 64 worked,
and the SQ overflow issue reproduced at 128.

Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

Hi,

>>> First, would it be helpful to limit maximum payload size per I/O for consumers
>>> based on number of iser-target sq hw sges..?
>>>
>> Assuming data is not able to be fast registered as if virtually contiguous;
>> artificially limiting the data size might not be the best solution.
>>
>> But max SGEs does need to be exposed higher. Somewhere in the stack,
>> there might need to be multiple WRs submitted or data copied.
>>
> 
> Sagi..?

I tend to agree that if the adapter support just a hand-full of sges its
counter-productive to expose infinite data transfer size. On the other
hand, I think we should be able to chunk more with memory registrations
(although rdma rw code never even allocates them for non-iwarp devices).

We have an API for check this in the RDMA core (thanks to chuck)
introduced in:
commit 0062818298662d0d05061949d12880146b5ebd65
Author: Chuck Lever <chuck.lever@oracle.com>
Date:   Mon Aug 28 15:06:14 2017 -0400

     rdma core: Add rdma_rw_mr_payload()

     The amount of payload per MR depends on device capabilities and
     the memory registration mode in use. The new rdma_rw API hides both,
     making it difficult for ULPs to determine how large their transport
     send queues need to be.

     Expose the MR payload information via a new API.

     Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
     Acked-by: Doug Ledford <dledford@redhat.com>
     Signed-off-by: J. Bruce Fields <bfields@redhat.com>


So the easy way out would be to use that and plug it to
max_sg_data_nents. Regardless, queue-full logic today yields a TX attack
on the transport.

>>> diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
>>> b/drivers/target/iscsi/iscsi_target_configf
>>> index 0ebc481..d8a4cc5 100644
>>> --- a/drivers/target/iscsi/iscsi_target_configfs.c
>>> +++ b/drivers/target/iscsi/iscsi_target_configfs.c
>>> @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
>>>          .module                         = THIS_MODULE,
>>>          .name                           = "iscsi",
>>>          .node_acl_size                  = sizeof(struct iscsi_node_acl),
>>> +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
>>> TRANSFER LENGTH */
>>>          .get_fabric_name                = iscsi_get_fabric_name,
>>>          .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
>>>          .tpg_get_tag                    = lio_tpg_get_tag,
>>>
>>
>> BTW, this is helping the SQ overflow issue.
> 
> Thanks for confirming as a possible work-around.
> 
> For reference, what is i40iw's max_send_sg reporting..?
> 
> Is max_data_sg_nents=32 + 4k pages = 128K the largest MAX TRANSFER
> LENGTH to avoid consistent SQ overflow as-is with i40iw..?

I vaguely recall that this is the maximum mr length for i40e (and cxgb4
if I'm not mistaken).

Re: SQ overflow seen running isert traffic with high block sizes

[Sagi Grimberg]

Hi,

>>> First, would it be helpful to limit maximum payload size per I/O for consumers
>>> based on number of iser-target sq hw sges..?
>>>
>> Assuming data is not able to be fast registered as if virtually contiguous;
>> artificially limiting the data size might not be the best solution.
>>
>> But max SGEs does need to be exposed higher. Somewhere in the stack,
>> there might need to be multiple WRs submitted or data copied.
>>
> 
> Sagi..?

I tend to agree that if the adapter support just a hand-full of sges its
counter-productive to expose infinite data transfer size. On the other
hand, I think we should be able to chunk more with memory registrations
(although rdma rw code never even allocates them for non-iwarp devices).

We have an API for check this in the RDMA core (thanks to chuck)
introduced in:
commit 0062818298662d0d05061949d12880146b5ebd65
Author: Chuck Lever <chuck.lever@oracle.com>
Date:   Mon Aug 28 15:06:14 2017 -0400

     rdma core: Add rdma_rw_mr_payload()

     The amount of payload per MR depends on device capabilities and
     the memory registration mode in use. The new rdma_rw API hides both,
     making it difficult for ULPs to determine how large their transport
     send queues need to be.

     Expose the MR payload information via a new API.

     Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
     Acked-by: Doug Ledford <dledford@redhat.com>
     Signed-off-by: J. Bruce Fields <bfields@redhat.com>


So the easy way out would be to use that and plug it to
max_sg_data_nents. Regardless, queue-full logic today yields a TX attack
on the transport.

>>> diff --git a/drivers/target/iscsi/iscsi_target_configfs.c
>>> b/drivers/target/iscsi/iscsi_target_configf
>>> index 0ebc481..d8a4cc5 100644
>>> --- a/drivers/target/iscsi/iscsi_target_configfs.c
>>> +++ b/drivers/target/iscsi/iscsi_target_configfs.c
>>> @@ -1553,6 +1553,7 @@ static void lio_release_cmd(struct se_cmd *se_cmd)
>>>          .module                         = THIS_MODULE,
>>>          .name                           = "iscsi",
>>>          .node_acl_size                  = sizeof(struct iscsi_node_acl),
>>> +       .max_data_sg_nents              = 32, /* 32 * PAGE_SIZE = MAXIMUM
>>> TRANSFER LENGTH */
>>>          .get_fabric_name                = iscsi_get_fabric_name,
>>>          .tpg_get_wwn                    = lio_tpg_get_endpoint_wwn,
>>>          .tpg_get_tag                    = lio_tpg_get_tag,
>>>
>>
>> BTW, this is helping the SQ overflow issue.
> 
> Thanks for confirming as a possible work-around.
> 
> For reference, what is i40iw's max_send_sg reporting..?
> 
> Is max_data_sg_nents2 + 4k pages = 128K the largest MAX TRANSFER
> LENGTH to avoid consistent SQ overflow as-is with i40iw..?

I vaguely recall that this is the maximum mr length for i40e (and cxgb4
if I'm not mistaken).