From: Christoph Hellwig <hch@infradead.org>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Ming Lei <ming.lei@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
Jens Axboe <axboe@kernel.dk>,
dm-devel@redhat.com, linux-block@vger.kernel.org
Subject: Re: [dm-devel] [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq
Date: Tue, 11 Jan 2022 00:34:30 -0800 [thread overview]
Message-ID: <Yd1BFpYTBlQSPReW@infradead.org> (raw)
In-Reply-To: <YcuB4K8P2d9WFb83@redhat.com>
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.
SCSI even has this:
/*
* SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so
* calling synchronize_rcu() once is enough.
*/
WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING);
next prev parent reply other threads:[~2022-01-11 8:34 UTC|newest]
Thread overview: 20+ 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 ` [PATCH 1/3] block: split having srcu from queue blocking Ming Lei
2022-01-11 18:13 ` [dm-devel] " Jeff Moyer
2021-12-21 14:14 ` [PATCH 2/3] block: add blk_alloc_disk_srcu Ming Lei
2022-01-11 18:13 ` [dm-devel] " Jeff Moyer
2021-12-21 14:14 ` [PATCH 3/3] dm: mark dm queue as blocking if any underlying is blocking Ming Lei
2022-01-06 15:40 ` Mike Snitzer
2022-01-06 15:51 ` Ming Lei
2022-01-10 19:23 ` Mike Snitzer
2022-01-11 18:14 ` [dm-devel] " Jeff Moyer
2021-12-21 16:21 ` [PATCH 0/3] blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq Christoph Hellwig
2021-12-23 4:16 ` Ming Lei
2021-12-28 21:30 ` Mike Snitzer
2022-01-10 19:26 ` Mike Snitzer
2022-01-11 8:34 ` Christoph Hellwig [this message]
2022-01-11 16:15 ` Mike Snitzer
2022-01-17 8:08 ` [dm-devel] " Christoph Hellwig
2022-01-11 18:23 ` Jeff Moyer
2022-01-17 8:10 ` Christoph Hellwig
2022-01-19 21:03 ` Mike Snitzer
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