From: Tejun Heo <tj@kernel.org>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>,
Kent Overstreet <koverstreet@google.com>,
Mikulas Patocka <mpatocka@redhat.com>,
linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org,
dm-devel@redhat.com, bharrosh@panasas.com,
Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH v7 9/9] block: Avoid deadlocks with bio allocation by stacking drivers
Date: Tue, 4 Sep 2012 11:26:33 -0700 [thread overview]
Message-ID: <20120904182633.GB3638@dhcp-172-17-108-109.mtv.corp.google.com> (raw)
In-Reply-To: <20120904135422.GC13768@redhat.com>
Hello,
On Tue, Sep 04, 2012 at 09:54:23AM -0400, Vivek Goyal wrote:
> > Given that we are working around stack depth issues in the
> > filesystems already in several places, and now it seems like there's
> > a reason to work around it in the block layers as well, shouldn't we
> > simply increase the default stack size rather than introduce
> > complexity and performance regressions to try and work around not
> > having enough stack?
>
> Dave,
>
> In this particular instance, we really don't have any bug reports of
> stack overflowing. Just discussing what will happen if we make
> generic_make_request() recursive again.
I think there was one and that's why we added the bio_list thing.
> > I mean, we can deal with it like the ia32 4k stack issue was dealt
> > with (i.e. ignore those stupid XFS people, that's an XFS bug), or
> > we can face the reality that storage stacks have become so complex
> > that 8k is no longer a big enough stack for a modern system....
>
> So first question will be, what's the right stack size? If we make
> generic_make_request() recursive, then at some storage stack depth we will
> overflow stack anyway (if we have created too deep a stack). Hence
> keeping current logic kind of makes sense as in theory we can support
> arbitrary depth of storage stack.
But, yeah, this can't be solved by enlarging the stack size. The
upper limit is unbound.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-09-04 18:26 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-28 17:37 [PATCH v7 0/9] Block cleanups, deadlock fix Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 1/9] block: Generalized bio pool freeing Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 2/9] dm: Use bioset's front_pad for dm_rq_clone_bio_info Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 3/9] block: Add bio_reset() Kent Overstreet
2012-08-28 20:31 ` Tejun Heo
2012-08-28 22:17 ` Kent Overstreet
2012-08-28 22:53 ` Kent Overstreet
2012-09-01 2:23 ` Tejun Heo
2012-09-05 20:13 ` Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 4/9] pktcdvd: Switch to bio_kmalloc() Kent Overstreet
2012-08-28 20:32 ` Tejun Heo
2012-08-28 22:24 ` Kent Overstreet
2012-09-04 9:05 ` Jiri Kosina
2012-09-05 19:44 ` Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 5/9] block: Kill bi_destructor Kent Overstreet
2012-08-28 20:36 ` Tejun Heo
2012-08-28 22:07 ` Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 6/9] block: Consolidate bio_alloc_bioset(), bio_kmalloc() Kent Overstreet
2012-08-28 20:41 ` Tejun Heo
2012-08-28 22:03 ` Kent Overstreet
2012-09-01 2:17 ` Tejun Heo
2012-08-28 17:37 ` [PATCH v7 7/9] block: Add bio_clone_bioset(), bio_clone_kmalloc() Kent Overstreet
2012-08-28 20:44 ` Tejun Heo
2012-08-28 22:05 ` Kent Overstreet
2012-09-01 2:19 ` Tejun Heo
2012-08-28 17:37 ` [PATCH v7 8/9] block: Reorder struct bio_set Kent Overstreet
2012-08-28 17:37 ` [PATCH v7 9/9] block: Avoid deadlocks with bio allocation by stacking drivers Kent Overstreet
2012-08-28 20:49 ` Tejun Heo
2012-08-28 22:28 ` Kent Overstreet
2012-08-28 23:01 ` Kent Overstreet
2012-08-29 1:31 ` Vivek Goyal
2012-08-29 3:25 ` Kent Overstreet
2012-08-29 12:57 ` Vivek Goyal
2012-08-29 14:39 ` [dm-devel] " Alasdair G Kergon
2012-08-29 16:26 ` Kent Overstreet
2012-08-29 21:01 ` John Stoffel
2012-08-29 21:08 ` Kent Overstreet
2012-08-28 22:06 ` Vivek Goyal
2012-08-28 22:23 ` Kent Overstreet
2012-08-29 16:24 ` Mikulas Patocka
2012-08-29 16:50 ` Kent Overstreet
2012-08-29 16:57 ` [dm-devel] " Alasdair G Kergon
2012-08-29 17:07 ` Vivek Goyal
2012-08-29 17:13 ` Kent Overstreet
2012-08-29 17:23 ` [dm-devel] " Alasdair G Kergon
2012-08-29 17:32 ` Kent Overstreet
2012-08-30 22:07 ` Vivek Goyal
2012-08-31 1:43 ` Kent Overstreet
2012-08-31 1:55 ` Kent Overstreet
2012-08-31 15:01 ` Vivek Goyal
2012-09-03 1:26 ` Kent Overstreet
2012-09-03 20:41 ` Mikulas Patocka
2012-09-04 3:41 ` Kent Overstreet
2012-09-04 18:55 ` Tejun Heo
2012-09-04 19:01 ` Tejun Heo
2012-09-04 19:43 ` Kent Overstreet
2012-09-04 19:42 ` Kent Overstreet
2012-09-04 21:03 ` Tejun Heo
2012-09-04 19:26 ` Mikulas Patocka
2012-09-04 19:39 ` Vivek Goyal
2012-09-04 19:51 ` [PATCH] dm: Use bioset's front_pad for dm_target_io Kent Overstreet
2012-09-04 21:20 ` Tejun Heo
2012-09-11 19:28 ` [PATCH 2] " Mikulas Patocka
2012-09-11 19:50 ` Kent Overstreet
2012-09-12 22:31 ` Mikulas Patocka
2012-09-14 23:09 ` [dm-devel] " Alasdair G Kergon
2012-09-01 2:13 ` [PATCH v7 9/9] block: Avoid deadlocks with bio allocation by stacking drivers Tejun Heo
2012-09-03 1:34 ` [PATCH v2] " Kent Overstreet
2012-09-04 15:00 ` [PATCH v7 9/9] " Vivek Goyal
2012-09-03 0:49 ` Dave Chinner
2012-09-03 1:17 ` Kent Overstreet
2012-09-04 13:54 ` Vivek Goyal
2012-09-04 18:26 ` Tejun Heo [this message]
2012-09-05 3:57 ` Dave Chinner
2012-09-05 4:37 ` Tejun Heo
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