From: Rik van Riel <riel@redhat.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [-mm][PATCH 4/5] core of reclaim throttle
Date: Mon, 5 May 2008 17:51:42 -0400 [thread overview]
Message-ID: <20080505175142.7de3f27b@cuia.bos.redhat.com> (raw)
In-Reply-To: <20080504221043.8F64.KOSAKI.MOTOHIRO@jp.fujitsu.com>
On Sun, 04 May 2008 22:12:12 +0900
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:
> + throttle_on = 1;
> + current->flags |= PF_RECLAIMING;
> + wait_event(zone->reclaim_throttle_waitq,
> + atomic_add_unless(&zone->nr_reclaimers, 1, MAX_RECLAIM_TASKS));
This is a problem. Processes without __GFP_FS or __GFP_IO cannot wait on
processes that have those flags set in their gfp_mask, and tasks that do
not have __GFP_IO set cannot wait for tasks with it. This is because the
tasks that have those flags set may grab locks that the tasks without the
flag are holding, causing a deadlock.
The easiest fix would be to only make tasks with both __GFP_FS and __GFP_IO
sleep. Tasks that call try_to_free_pages without those flags are relatively
rare and should hopefully not cause any issues.
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next prev parent reply other threads:[~2008-05-05 21:51 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-04 12:53 [-mm][PATCH 0/5] mm: page reclaim throttle v6 KOSAKI Motohiro
2008-05-04 12:55 ` [-mm][PATCH 1/5] fix overflow problem of do_try_to_free_page() KOSAKI Motohiro
2008-05-05 8:12 ` Nishanth Aravamudan
2008-05-06 3:29 ` KOSAKI Motohiro
2008-05-04 12:57 ` [-mm][PATCH 2/5] introduce get_vm_event() KOSAKI Motohiro
2008-05-05 21:47 ` Rik van Riel
2008-05-04 12:58 ` [-mm][PATCH 3/5] change function prototype of shrink_zone() KOSAKI Motohiro
2008-05-05 4:42 ` minchan Kim
2008-05-05 8:31 ` KOSAKI Motohiro
2008-05-05 8:37 ` minchan Kim
2008-05-04 12:59 ` [-mm][PATCH 4/5] core of reclaim throttle KOSAKI Motohiro
2008-05-04 13:12 ` KOSAKI Motohiro
2008-05-05 5:21 ` minchan Kim
2008-05-05 8:24 ` KOSAKI Motohiro
2008-05-05 8:32 ` minchan Kim
2008-05-05 21:51 ` Rik van Riel [this message]
2008-05-05 22:23 ` KOSAKI Motohiro
2008-05-06 0:43 ` Rik van Riel
2008-05-06 1:01 ` KOSAKI Motohiro
2008-05-04 13:01 ` [-mm][PATCH 5/5] introduce sysctl parameter of max task of throttle KOSAKI Motohiro
2008-05-04 14:38 ` [-mm][PATCH 0/5] mm: page reclaim throttle v6 KOSAKI Motohiro
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