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From: Jeff Moyer <jmoyer@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Mike Snitzer <snitzer@redhat.com>, Jens Axboe <axboe@kernel.dk>,
	dm-devel@redhat.com, linux-block@vger.kernel.org,
	Ming Lei <ming.lei@redhat.com>
Subject: Re: [dm-devel] [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq
Date: Tue, 11 Jan 2022 13:23:53 -0500	[thread overview]
Message-ID: <x49ee5ejfly.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <Yd1BFpYTBlQSPReW@infradead.org> (Christoph Hellwig's message of "Tue, 11 Jan 2022 00:34:30 -0800")

Christoph Hellwig <hch@infradead.org> writes:

> On Tue, Dec 28, 2021 at 04:30:08PM -0500, Mike Snitzer wrote:
>> Yeah, people use request-based for IO scheduling and more capable path
>> selectors. Imposing bio-based would be a pretty jarring workaround for 
>> BLK_MQ_F_BLOCKING. request-based DM should properly support it.
>
> Given that nvme-tcp is the only blocking driver that has multipath
> driver that driver explicitly does not intend to support dm-multipath
> I'm absolutely against adding block layer cruft for this particular
> use case.

Maybe I have bad taste, but the patches didn't look like cruft to me.
:)

I'm not sure why we'd prevent users from using dm-mpath on nvmeof.  I
think there's agreement that the nvme native multipath implementation is
the preferred way (that's the default in rhel9, even), but I don't think
that's a reason to nack this patch set.

Or have I missed your point entirely?

Thanks!
Jeff


WARNING: multiple messages have this Message-ID (diff)
From: Jeff Moyer <jmoyer@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, dm-devel@redhat.com,
	Mike Snitzer <snitzer@redhat.com>, Ming Lei <ming.lei@redhat.com>
Subject: Re: [dm-devel] [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq
Date: Tue, 11 Jan 2022 13:23:53 -0500	[thread overview]
Message-ID: <x49ee5ejfly.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <Yd1BFpYTBlQSPReW@infradead.org> (Christoph Hellwig's message of "Tue, 11 Jan 2022 00:34:30 -0800")

Christoph Hellwig <hch@infradead.org> writes:

> On Tue, Dec 28, 2021 at 04:30:08PM -0500, Mike Snitzer wrote:
>> Yeah, people use request-based for IO scheduling and more capable path
>> selectors. Imposing bio-based would be a pretty jarring workaround for 
>> BLK_MQ_F_BLOCKING. request-based DM should properly support it.
>
> Given that nvme-tcp is the only blocking driver that has multipath
> driver that driver explicitly does not intend to support dm-multipath
> I'm absolutely against adding block layer cruft for this particular
> use case.

Maybe I have bad taste, but the patches didn't look like cruft to me.
:)

I'm not sure why we'd prevent users from using dm-mpath on nvmeof.  I
think there's agreement that the nvme native multipath implementation is
the preferred way (that's the default in rhel9, even), but I don't think
that's a reason to nack this patch set.

Or have I missed your point entirely?

Thanks!
Jeff

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel


  parent reply	other threads:[~2022-01-11 18:21 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-21 14:14 [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq Ming Lei
2021-12-21 14:14 ` [dm-devel] " Ming Lei
2021-12-21 14:14 ` [PATCH 1/3] block: split having srcu from queue blocking Ming Lei
2021-12-21 14:14   ` [dm-devel] " Ming Lei
2022-01-11 18:13   ` Jeff Moyer
2022-01-11 18:13     ` Jeff Moyer
2021-12-21 14:14 ` [PATCH 2/3] block: add blk_alloc_disk_srcu Ming Lei
2021-12-21 14:14   ` [dm-devel] " Ming Lei
2022-01-11 18:13   ` Jeff Moyer
2022-01-11 18:13     ` Jeff Moyer
2021-12-21 14:14 ` [PATCH 3/3] dm: mark dm queue as blocking if any underlying is blocking Ming Lei
2021-12-21 14:14   ` [dm-devel] " Ming Lei
2022-01-06 15:40   ` Mike Snitzer
2022-01-06 15:40     ` [dm-devel] " Mike Snitzer
2022-01-06 15:51     ` Ming Lei
2022-01-06 15:51       ` [dm-devel] " Ming Lei
2022-01-10 19:23       ` Mike Snitzer
2022-01-10 19:23         ` [dm-devel] " Mike Snitzer
2022-01-11 18:14   ` Jeff Moyer
2022-01-11 18:14     ` Jeff Moyer
2021-12-21 16:21 ` [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq Christoph Hellwig
2021-12-21 16:21   ` [dm-devel] " Christoph Hellwig
2021-12-23  4:16   ` Ming Lei
2021-12-23  4:16     ` [dm-devel] " Ming Lei
2021-12-28 21:30     ` Mike Snitzer
2021-12-28 21:30       ` [dm-devel] " Mike Snitzer
2022-01-10 19:26       ` Mike Snitzer
2022-01-10 19:26         ` [dm-devel] " Mike Snitzer
2022-01-11  8:34       ` Christoph Hellwig
2022-01-11  8:34         ` Christoph Hellwig
2022-01-11 16:15         ` Mike Snitzer
2022-01-11 16:15           ` [dm-devel] " Mike Snitzer
2022-01-17  8:08           ` Christoph Hellwig
2022-01-17  8:08             ` Christoph Hellwig
2022-01-11 18:23         ` Jeff Moyer [this message]
2022-01-11 18:23           ` Jeff Moyer
2022-01-17  8:10           ` Christoph Hellwig
2022-01-17  8:10             ` Christoph Hellwig
2022-01-19 21:03             ` Mike Snitzer
2022-01-19 21:03               ` [dm-devel] " Mike Snitzer

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