From: Rik van Riel <riel@redhat.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH -mm] throttle direct reclaim when too many pages are isolated already (v3)
Date: Wed, 29 Jul 2009 12:19:34 -0400 [thread overview]
Message-ID: <4A707696.6080301@redhat.com> (raw)
In-Reply-To: <20090729150443.GB1534@ucw.cz>
Pavel Machek wrote:
> On Wed 2009-07-15 23:53:18, Rik van Riel wrote:
>> When way too many processes go into direct reclaim, it is possible
>> for all of the pages to be taken off the LRU. One result of this
>> is that the next process in the page reclaim code thinks there are
>> no reclaimable pages left and triggers an out of memory kill.
>>
>> One solution to this problem is to never let so many processes into
>> the page reclaim path that the entire LRU is emptied. Limiting the
>> system to only having half of each inactive list isolated for
>> reclaim should be safe.
>
> Is this still racy? Like on 100cpu machine, with LRU size of 50...?
If a 100 CPU system gets down to just 100 reclaimable pages,
getting the OOM killer to trigger sounds desirable.
The goal of this patch is to avoid _false_ OOM kills, when
the system still has enough reclaimable memory available.
--
All rights reversed.
WARNING: multiple messages have this Message-ID (diff)
From: Rik van Riel <riel@redhat.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH -mm] throttle direct reclaim when too many pages are isolated already (v3)
Date: Wed, 29 Jul 2009 12:19:34 -0400 [thread overview]
Message-ID: <4A707696.6080301@redhat.com> (raw)
In-Reply-To: <20090729150443.GB1534@ucw.cz>
Pavel Machek wrote:
> On Wed 2009-07-15 23:53:18, Rik van Riel wrote:
>> When way too many processes go into direct reclaim, it is possible
>> for all of the pages to be taken off the LRU. One result of this
>> is that the next process in the page reclaim code thinks there are
>> no reclaimable pages left and triggers an out of memory kill.
>>
>> One solution to this problem is to never let so many processes into
>> the page reclaim path that the entire LRU is emptied. Limiting the
>> system to only having half of each inactive list isolated for
>> reclaim should be safe.
>
> Is this still racy? Like on 100cpu machine, with LRU size of 50...?
If a 100 CPU system gets down to just 100 reclaimable pages,
getting the OOM killer to trigger sounds desirable.
The goal of this patch is to avoid _false_ OOM kills, when
the system still has enough reclaimable memory available.
--
All rights reversed.
--
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next prev parent reply other threads:[~2009-07-29 16:20 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-16 2:38 [PATCH -mm] throttle direct reclaim when too many pages are isolated already Rik van Riel
2009-07-16 2:38 ` Rik van Riel
2009-07-16 2:48 ` Andrew Morton
2009-07-16 2:48 ` Andrew Morton
2009-07-16 3:10 ` Rik van Riel
2009-07-16 3:10 ` Rik van Riel
2009-07-16 3:21 ` Andrew Morton
2009-07-16 3:21 ` Andrew Morton
2009-07-16 3:28 ` Rik van Riel
2009-07-16 3:28 ` Rik van Riel
2009-07-16 3:38 ` Andrew Morton
2009-07-16 3:38 ` Andrew Morton
2009-07-16 3:42 ` Rik van Riel
2009-07-16 3:42 ` Rik van Riel
2009-07-16 3:51 ` Andrew Morton
2009-07-16 3:51 ` Andrew Morton
2009-07-16 3:53 ` [PATCH -mm] throttle direct reclaim when too many pages are isolated already (v3) Rik van Riel
2009-07-16 3:53 ` Rik van Riel
2009-07-16 4:02 ` Andrew Morton
2009-07-16 4:02 ` Andrew Morton
2009-07-16 4:09 ` Rik van Riel
2009-07-16 4:09 ` Rik van Riel
2009-07-16 4:26 ` Andrew Morton
2009-07-16 4:26 ` Andrew Morton
2009-07-29 15:04 ` Pavel Machek
2009-07-29 15:04 ` Pavel Machek
2009-07-29 16:19 ` Rik van Riel [this message]
2009-07-29 16:19 ` Rik van Riel
2009-07-16 3:36 ` [PATCH -mm] throttle direct reclaim when too many pages are isolated already (v2) Rik van Riel
2009-07-16 3:36 ` Rik van Riel
2009-07-16 3:19 ` [PATCH -mm] throttle direct reclaim when too many pages are isolated already KAMEZAWA Hiroyuki
2009-07-16 3:19 ` KAMEZAWA Hiroyuki
2009-07-16 3:32 ` Rik van Riel
2009-07-16 3:32 ` Rik van Riel
2009-07-16 3:42 ` KAMEZAWA Hiroyuki
2009-07-16 3:42 ` KAMEZAWA Hiroyuki
2009-07-16 3:47 ` Rik van Riel
2009-07-16 3:47 ` Rik van Riel
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