linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: Tom Talpey <tom@talpey.com>
Cc: Haakon Bugge <haakon.bugge@oracle.com>,
	David Laight <David.Laight@aculab.com>,
	Chuck Lever III <chuck.lever@oracle.com>,
	Christoph Hellwig <hch@lst.de>, Leon Romanovsky <leon@kernel.org>,
	Doug Ledford <dledford@redhat.com>,
	Leon Romanovsky <leonro@nvidia.com>,
	Adit Ranadive <aditr@vmware.com>,
	Anna Schumaker <anna.schumaker@netapp.com>,
	Ariel Elior <aelior@marvell.com>,
	Avihai Horon <avihaih@nvidia.com>,
	Bart Van Assche <bvanassche@acm.org>,
	Bernard Metzler <bmt@zurich.ibm.com>,
	"David S. Miller" <davem@davemloft.net>,
	Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>,
	Devesh Sharma <devesh.sharma@broadcom.com>,
	Faisal Latif <faisal.latif@intel.com>,
	Jack Wang <jinpu.wang@ionos.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Bruce Fields <bfields@fieldses.org>, Jens Axboe <axboe@fb.com>,
	Karsten Graul <kgraul@linux.ibm.com>,
	Keith Busch <kbusch@kernel.org>, Lijun Ou <oulijun@huawei.com>,
	CIFS <linux-cifs@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	OFED mailing list <linux-rdma@vger.kernel.org>,
	"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
	Max Gurtovoy <maxg@mellanox.com>,
	Max Gurtovoy <mgurtovoy@nvidia.com>,
	"Md. Haris Iqbal" <haris.iqbal@ionos.com>,
	Michael Guralnik <michaelgur@nvidia.com>,
	Michal Kalderon <mkalderon@marvell.com>,
	Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>,
	Naresh Kumar PBS <nareshkumar.pbs@broadcom.com>,
	Linux-Net <netdev@vger.kernel.org>,
	Potnuri Bharat Teja <bharat@chelsio.com>,
	"rds-devel@oss.oracle.com" <rds-devel@oss.oracle.com>,
	Sagi Grimberg <sagi@grimberg.me>,
	"samba-technical@lists.samba.org"
	<samba-technical@lists.samba.org>,
	Santosh Shilimkar <santosh.shilimkar@oracle.com>,
	Selvin Xavier <selvin.xavier@broadcom.com>,
	Shiraz Saleem <shiraz.saleem@intel.com>,
	Somnath Kotur <somnath.kotur@broadcom.com>,
	Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>,
	Steve French <sfrench@samba.org>,
	Trond Myklebust <trond.myklebust@hammerspace.com>,
	VMware PV-Drivers <pv-drivers@vmware.com>,
	Weihang Li <liweihang@huawei.com>,
	Yishai Hadas <yishaih@nvidia.com>,
	Zhu Yanjun <zyjzyj2000@gmail.com>
Subject: Re: [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs
Date: Wed, 14 Apr 2021 11:44:52 -0300	[thread overview]
Message-ID: <20210414144452.GC1370958@nvidia.com> (raw)
In-Reply-To: <02593083-056e-cc62-22cf-d6bd6c9b18a8@talpey.com>

On Wed, Apr 14, 2021 at 10:16:28AM -0400, Tom Talpey wrote:
> On 4/12/2021 6:48 PM, Jason Gunthorpe wrote:
> > On Mon, Apr 12, 2021 at 04:20:47PM -0400, Tom Talpey wrote:
> > 
> > > So the issue is only in testing all the providers and platforms,
> > > to be sure this new behavior isn't tickling anything that went
> > > unnoticed all along, because no RDMA provider ever issued RO.
> > 
> > The mlx5 ethernet driver has run in RO mode for a long time, and it
> > operates in basically the same way as RDMA. The issues with Haswell
> > have been worked out there already.
> > 
> > The only open question is if the ULPs have errors in their
> > implementation, which I don't think we can find out until we apply
> > this series and people start running their tests aggressively.
> 
> I agree that the core RO support should go in. But turning it on
> by default for a ULP should be the decision of each ULP maintainer.
> It's a huge risk to shift all the storage drivers overnight. How
> do you propose to ensure the aggressive testing happens?

Realistically we do test most of the RDMA storage ULPs at NVIDIA over
mlx5 which is the only HW that will enable this for now.

I disagree it is a "huge risk".

Additional wider testing is welcomed and can happen over the 16 week
release cycle for a kernel. I would aim to get the relaxed ordering
changed merged to linux-next a week or so after the merge window.

Further testing happens before these changes would get picked up in a
distro on something like MLNX_OFED.

I don't think we need to make the patch design worse or over think the
submission process for something that, so far, hasn't discovered any
issues and alread has a proven track record in other ULPs.

Any storage ULP that has a problem here is mis-using verbs and the DMA
API and thus has an existing data-corruption bug that they are simply
lucky to have not yet discovered.

> One thing that worries me is the patch02 on-by-default for the dma_lkey.
> There's no way for a ULP to prevent IB_ACCESS_RELAXED_ORDERING
> from being set in __ib_alloc_pd().

The ULPs are being forced into relaxed_ordering. They don't get to
turn it off one by one. The v2 will be more explicit about this as
there will be no ULP patches, just the verbs core code being updated.

Jason

  parent reply	other threads:[~2021-04-14 14:45 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-05  5:23 [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs Leon Romanovsky
2021-04-05  5:23 ` [PATCH rdma-next 01/10] RDMA: Add access flags to ib_alloc_mr() and ib_mr_pool_init() Leon Romanovsky
2021-04-05 13:46   ` Christoph Hellwig
2021-04-06  5:24     ` Leon Romanovsky
2021-04-05 15:27   ` Bart Van Assche
2021-04-06  5:23     ` Leon Romanovsky
2021-04-06  5:27       ` Christoph Hellwig
2021-04-06  5:58         ` Leon Romanovsky
2021-04-06 12:13           ` Jason Gunthorpe
2021-04-06 12:30             ` Christoph Hellwig
2021-04-06 14:04               ` Jason Gunthorpe
2021-04-06 14:15                 ` Christoph Hellwig
2021-04-06 14:40                   ` Jason Gunthorpe
2021-04-06 14:54                     ` Christoph Hellwig
2021-04-06 15:03                       ` Christoph Hellwig
2021-04-07 18:28                       ` Jason Gunthorpe
2021-04-05  5:23 ` [PATCH rdma-next 02/10] RDMA/core: Enable Relaxed Ordering in __ib_alloc_pd() Leon Romanovsky
2021-04-05 18:01   ` Tom Talpey
2021-04-05 20:40     ` Adit Ranadive
2021-04-06  6:28     ` Leon Romanovsky
2021-04-05  5:23 ` [PATCH rdma-next 03/10] RDMA/iser: Enable Relaxed Ordering Leon Romanovsky
2021-04-05  5:23 ` [PATCH rdma-next 04/10] RDMA/rtrs: " Leon Romanovsky
2021-04-05  5:23 ` [PATCH rdma-next 05/10] RDMA/srp: " Leon Romanovsky
2021-04-05  5:24 ` [PATCH rdma-next 06/10] nvme-rdma: " Leon Romanovsky
2021-04-05  5:24 ` [PATCH rdma-next 07/10] cifs: smbd: " Leon Romanovsky
2021-04-05  5:24 ` [PATCH rdma-next 08/10] net/rds: " Leon Romanovsky
2021-04-05  5:24 ` [PATCH rdma-next 09/10] net/smc: " Leon Romanovsky
2021-04-05  5:24 ` [PATCH rdma-next 10/10] xprtrdma: " Leon Romanovsky
2021-04-05 13:41 ` [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs Christoph Hellwig
2021-04-05 14:08   ` Leon Romanovsky
2021-04-05 16:11     ` Santosh Shilimkar
2021-04-05 17:54     ` Tom Talpey
2021-04-05 20:07   ` Jason Gunthorpe
2021-04-05 23:42     ` Chuck Lever III
2021-04-05 23:50       ` Keith Busch
2021-04-06  5:12       ` Leon Romanovsky
2021-04-06 11:49       ` Jason Gunthorpe
2021-04-09 14:26         ` Tom Talpey
2021-04-09 14:45           ` Chuck Lever III
2021-04-09 15:32             ` Tom Talpey
2021-04-09 16:27               ` Haakon Bugge
2021-04-09 17:49                 ` Tom Talpey
2021-04-10 13:30                   ` David Laight
2021-04-12 18:32                     ` Haakon Bugge
2021-04-12 20:20                       ` Tom Talpey
2021-04-12 22:48                         ` Jason Gunthorpe
2021-04-14 14:16                           ` Tom Talpey
2021-04-14 14:41                             ` David Laight
2021-04-14 14:49                               ` Jason Gunthorpe
2021-04-14 14:44                             ` Jason Gunthorpe [this message]
2021-04-09 16:40           ` Jason Gunthorpe
2021-04-09 17:44             ` Tom Talpey
2021-04-06  2:37 ` Honggang LI
2021-04-06  5:09   ` Leon Romanovsky
2021-04-06 11:53     ` Jason Gunthorpe
2021-04-11 10:09       ` Max Gurtovoy

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210414144452.GC1370958@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=David.Laight@aculab.com \
    --cc=aditr@vmware.com \
    --cc=aelior@marvell.com \
    --cc=anna.schumaker@netapp.com \
    --cc=avihaih@nvidia.com \
    --cc=axboe@fb.com \
    --cc=bfields@fieldses.org \
    --cc=bharat@chelsio.com \
    --cc=bmt@zurich.ibm.com \
    --cc=bvanassche@acm.org \
    --cc=chuck.lever@oracle.com \
    --cc=davem@davemloft.net \
    --cc=dennis.dalessandro@cornelisnetworks.com \
    --cc=devesh.sharma@broadcom.com \
    --cc=dledford@redhat.com \
    --cc=faisal.latif@intel.com \
    --cc=haakon.bugge@oracle.com \
    --cc=haris.iqbal@ionos.com \
    --cc=hch@lst.de \
    --cc=jinpu.wang@ionos.com \
    --cc=kbusch@kernel.org \
    --cc=kgraul@linux.ibm.com \
    --cc=kuba@kernel.org \
    --cc=leon@kernel.org \
    --cc=leonro@nvidia.com \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=linux-nvme@lists.infradead.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=liweihang@huawei.com \
    --cc=maxg@mellanox.com \
    --cc=mgurtovoy@nvidia.com \
    --cc=michaelgur@nvidia.com \
    --cc=mike.marciniszyn@cornelisnetworks.com \
    --cc=mkalderon@marvell.com \
    --cc=nareshkumar.pbs@broadcom.com \
    --cc=netdev@vger.kernel.org \
    --cc=oulijun@huawei.com \
    --cc=pv-drivers@vmware.com \
    --cc=rds-devel@oss.oracle.com \
    --cc=sagi@grimberg.me \
    --cc=samba-technical@lists.samba.org \
    --cc=santosh.shilimkar@oracle.com \
    --cc=selvin.xavier@broadcom.com \
    --cc=sfrench@samba.org \
    --cc=shiraz.saleem@intel.com \
    --cc=somnath.kotur@broadcom.com \
    --cc=sriharsha.basavapatna@broadcom.com \
    --cc=tom@talpey.com \
    --cc=trond.myklebust@hammerspace.com \
    --cc=yishaih@nvidia.com \
    --cc=zyjzyj2000@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).