From: Mike Snitzer <snitzer@redhat.com>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
kent.overstreet@gmail.com, dm-devel@redhat.com,
linux-kernel@vger.kernel.org,
"Alasdair G. Kergon" <agk@redhat.com>
Subject: Re: [PATCH v2] block: flush queued bios when the process blocks
Date: Fri, 9 Oct 2015 15:59:07 -0400 [thread overview]
Message-ID: <20151009195907.GB18790@redhat.com> (raw)
In-Reply-To: <20151009195203.GA18790@redhat.com>
On Fri, Oct 09 2015 at 3:52pm -0400,
Mike Snitzer <snitzer@redhat.com> wrote:
> Turns out that this change:
> http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/commit/?h=wip&id=2639638c77768a86216be456c2764e32a2bcd841
>
> needed to be reverted with:
> http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/commit/?h=wip&id=ad3ccd760da7c05b90775372f9b39dc2964086fe
>
> Because nested plugs caused generic_make_request()'s onstack bio_list to
> go out of scope (blk_finish_plug() wouldn't actually flush the list
> within generic_make_request because XFS already added an outermost
> plug).
>
> But even after fixing that I then hit issues with these changes now
> resulting in imperfect 'in_generic_make_request' accounting that happens
> lazily once the outermost plug completes blk_finish_plug. manifested as
> dm-bufio.c:dm_bufio_prefetch's BUG_ON(dm_bufio_in_request()); hitting.
>
> Basically using the blk-core's onstack plugging isn't workable for
> fixing this deadlock and we're back to having to seriously consider
> this (with its additional hook in the scheduler):
http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/commit/?h=wip&id=a91709cd32b5ca7ca047b68c9299e747f2ae6ca2
next prev parent reply other threads:[~2015-10-09 19:59 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-27 15:03 [PATCH] block: flush queued bios when the process blocks Mikulas Patocka
2014-05-27 15:08 ` Jens Axboe
2014-05-27 15:23 ` Mikulas Patocka
2014-05-27 15:42 ` Jens Axboe
2014-05-27 16:26 ` Mikulas Patocka
2014-05-27 17:33 ` Mike Snitzer
2014-05-27 19:56 ` Kent Overstreet
2015-10-05 19:50 ` Mike Snitzer
2014-05-27 17:42 ` [PATCH] " Jens Axboe
2014-05-27 18:14 ` [dm-devel] " Christoph Hellwig
2014-05-27 19:59 ` Kent Overstreet
2014-05-27 19:56 ` Mikulas Patocka
2014-05-27 20:06 ` Kent Overstreet
2014-05-29 23:52 ` Mikulas Patocka
2015-10-05 20:59 ` Mike Snitzer
2015-10-06 13:28 ` Mikulas Patocka
2015-10-06 13:47 ` Mike Snitzer
2015-10-06 14:10 ` Mikulas Patocka
2015-10-06 14:26 ` Mikulas Patocka
2015-10-06 18:17 ` [dm-devel] " Mikulas Patocka
2015-10-06 18:50 ` Mike Snitzer
2015-10-06 20:16 ` [PATCH v2] " Mike Snitzer
2015-10-06 20:26 ` Mike Snitzer
2015-10-08 15:04 ` Mikulas Patocka
2015-10-08 15:08 ` Mike Snitzer
2015-10-09 19:52 ` Mike Snitzer
2015-10-09 19:59 ` Mike Snitzer [this message]
2015-10-14 20:47 ` [PATCH v3 for-4.4] block: flush queued bios when process blocks to avoid deadlock Mike Snitzer
2015-10-14 21:44 ` Jeff Moyer
2015-10-17 16:04 ` Ming Lei
2015-10-20 19:57 ` Mike Snitzer
2015-10-20 20:03 ` Mikulas Patocka
2015-10-21 16:38 ` Ming Lei
2015-10-21 21:49 ` Mikulas Patocka
2015-10-22 1:53 ` Ming Lei
2015-10-15 3:27 ` [PATCH v2] block: flush queued bios when the process blocks Ming Lei
2015-10-15 8:06 ` Mike Snitzer
2015-10-16 3:08 ` Ming Lei
2015-10-16 15:29 ` Mike Snitzer
2015-10-17 15:54 ` Ming Lei
2015-10-09 11:58 ` kbuild test robot
2014-05-27 17:59 ` [PATCH] " Kent Overstreet
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