From: Wu Fengguang <fengguang.wu@intel.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Torsten Kaiser <just.for.lkml@googlemail.com>,
Neil Brown <neilb@suse.de>, Rik van Riel <riel@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"Li, Shaohua" <shaohua.li@intel.com>
Subject: Re: Deadlock possibly caused by too_many_isolated.
Date: Fri, 22 Oct 2010 16:07:25 +0800 [thread overview]
Message-ID: <20101022080725.GA22594@localhost> (raw)
In-Reply-To: <20101022053755.GB16804@localhost>
> > We surely need 1 set aside for each level of that stack that will
> > potentially consume one. 1 should be enough for the generic pool, and
> > then clones will use a separate pool. So md and friends should really
> > have a pool per device, so that stacking will always work properly.
>
> Agreed for the deadlock problem.
>
> > There should be no throughput concerns, it should purely be a safe guard
> > measure to prevent us deadlocking when doing IO for reclaim.
>
> It's easy to verify whether the minimal size will have negative
> impacts on IO throughput. In Torsten's case, increase BIO_POOL_SIZE
> by one and check how it performs.
Sorry it seems simply increasing BIO_POOL_SIZE is not enough to fix
possible deadlocks. We need adding new mempool(s). Because when there
BIO_POOL_SIZE=2 and there are two concurrent reclaimers each take 1
reservation, they will deadlock each other when trying to take the
next bio at the raid1 level.
Thanks,
Fengguang
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next prev parent reply other threads:[~2010-10-22 8:07 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-14 23:11 Deadlock possibly caused by too_many_isolated Neil Brown
2010-09-15 0:30 ` Rik van Riel
2010-09-15 2:23 ` Neil Brown
2010-09-15 2:37 ` Wu Fengguang
2010-09-15 2:54 ` Wu Fengguang
2010-09-15 3:06 ` Wu Fengguang
2010-09-15 3:13 ` Wu Fengguang
2010-09-15 3:18 ` Shaohua Li
2010-09-15 3:31 ` Wu Fengguang
2010-09-15 3:17 ` Neil Brown
2010-09-15 3:47 ` Wu Fengguang
2010-09-15 8:28 ` Wu Fengguang
2010-09-15 8:44 ` Neil Brown
2010-10-18 4:14 ` Neil Brown
2010-10-18 5:04 ` KOSAKI Motohiro
2010-10-18 10:58 ` Torsten Kaiser
2010-10-18 23:11 ` Neil Brown
2010-10-19 8:43 ` Torsten Kaiser
2010-10-19 10:06 ` Torsten Kaiser
2010-10-20 5:57 ` Wu Fengguang
2010-10-20 7:05 ` KOSAKI Motohiro
2010-10-20 9:27 ` Wu Fengguang
2010-10-20 13:03 ` Jens Axboe
2010-10-22 5:37 ` Wu Fengguang
2010-10-22 8:07 ` Wu Fengguang [this message]
2010-10-22 8:09 ` Jens Axboe
2010-10-24 16:52 ` Wu Fengguang
2010-10-25 6:40 ` Neil Brown
2010-10-25 7:26 ` Wu Fengguang
2010-10-20 7:25 ` Torsten Kaiser
2010-10-20 9:01 ` Wu Fengguang
2010-10-20 10:07 ` Torsten Kaiser
2010-10-20 14:23 ` Minchan Kim
2010-10-20 15:35 ` Torsten Kaiser
2010-10-20 23:31 ` Minchan Kim
2010-10-18 16:15 ` Wu Fengguang
2010-10-18 21:58 ` Andrew Morton
2010-10-18 22:31 ` Neil Brown
2010-10-18 22:41 ` Andrew Morton
2010-10-19 0:57 ` KOSAKI Motohiro
2010-10-19 1:15 ` Minchan Kim
2010-10-19 1:21 ` KOSAKI Motohiro
2010-10-19 1:32 ` Minchan Kim
2010-10-19 2:03 ` KOSAKI Motohiro
2010-10-19 2:16 ` Minchan Kim
2010-10-19 2:54 ` KOSAKI Motohiro
2010-10-19 2:35 ` Wu Fengguang
2010-10-19 2:52 ` Minchan Kim
2010-10-19 3:05 ` Wu Fengguang
2010-10-19 3:09 ` Minchan Kim
2010-10-19 3:13 ` KOSAKI Motohiro
2010-10-19 5:11 ` Minchan Kim
2010-10-19 3:21 ` Shaohua Li
2010-10-19 7:15 ` Shaohua Li
2010-10-19 7:34 ` Minchan Kim
2010-10-19 2:24 ` Wu Fengguang
2010-10-19 2:37 ` KOSAKI Motohiro
2010-10-19 2:37 ` Minchan Kim
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