From: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Mel Gorman <mgorman@suse.de>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
Xishi Qiu <qiuxishi@huawei.com>,
Wen Congyang <wency@cn.fujitsu.com>
Subject: Re: [PATCH v3 4/4] memory-hotplug: fix pages missed by race rather than failng
Date: Fri, 07 Sep 2012 09:48:51 +0900 [thread overview]
Message-ID: <50494473.8030008@jp.fujitsu.com> (raw)
In-Reply-To: <1346978372-17903-5-git-send-email-minchan@kernel.org>
(2012/09/07 9:39), Minchan Kim wrote:
> If race between allocation and isolation in memory-hotplug offline
> happens, some pages could be in MIGRATE_MOVABLE of free_list although
> the pageblock's migratetype of the page is MIGRATE_ISOLATE.
>
> The race could be detected by get_freepage_migratetype
> in __test_page_isolated_in_pageblock. If it is detected, now EBUSY
> gets bubbled all the way up and the hotplug operations fails.
>
> But better idea is instead of returning and failing memory-hotremove,
> move the free page to the correct list at the time it is detected.
> It could enhance memory-hotremove operation success ratio although
> the race is really rare.
>
> Suggested-by: Mel Gorman <mgorman@suse.de>
> Signed-off-by: Minchan Kim <minchan@kernel.org>
Sounds reasonable. Thank you very much !
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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WARNING: multiple messages have this Message-ID (diff)
From: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Mel Gorman <mgorman@suse.de>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
Xishi Qiu <qiuxishi@huawei.com>,
Wen Congyang <wency@cn.fujitsu.com>
Subject: Re: [PATCH v3 4/4] memory-hotplug: fix pages missed by race rather than failng
Date: Fri, 07 Sep 2012 09:48:51 +0900 [thread overview]
Message-ID: <50494473.8030008@jp.fujitsu.com> (raw)
In-Reply-To: <1346978372-17903-5-git-send-email-minchan@kernel.org>
(2012/09/07 9:39), Minchan Kim wrote:
> If race between allocation and isolation in memory-hotplug offline
> happens, some pages could be in MIGRATE_MOVABLE of free_list although
> the pageblock's migratetype of the page is MIGRATE_ISOLATE.
>
> The race could be detected by get_freepage_migratetype
> in __test_page_isolated_in_pageblock. If it is detected, now EBUSY
> gets bubbled all the way up and the hotplug operations fails.
>
> But better idea is instead of returning and failing memory-hotremove,
> move the free page to the correct list at the time it is detected.
> It could enhance memory-hotremove operation success ratio although
> the race is really rare.
>
> Suggested-by: Mel Gorman <mgorman@suse.de>
> Signed-off-by: Minchan Kim <minchan@kernel.org>
Sounds reasonable. Thank you very much !
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
next prev parent reply other threads:[~2012-09-07 0:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-07 0:39 [PATCH v3 0/4] memory-hotplug: handle page race between allocation and isolation Minchan Kim
2012-09-07 0:39 ` Minchan Kim
2012-09-07 0:39 ` [PATCH v3 1/4] use get_freepage_migratetype instead of page_private Minchan Kim
2012-09-07 0:39 ` Minchan Kim
2012-09-07 3:50 ` Yasuaki Ishimatsu
2012-09-07 3:50 ` Yasuaki Ishimatsu
2012-09-07 0:39 ` [PATCH v3 2/4] mm: remain migratetype in freed page Minchan Kim
2012-09-07 0:39 ` Minchan Kim
2012-09-07 3:51 ` Yasuaki Ishimatsu
2012-09-07 3:51 ` Yasuaki Ishimatsu
2012-09-07 0:39 ` [PATCH v3 3/4] memory-hotplug: bug fix race between isolation and allocation Minchan Kim
2012-09-07 0:39 ` Minchan Kim
2012-09-07 3:52 ` Yasuaki Ishimatsu
2012-09-07 3:52 ` Yasuaki Ishimatsu
2012-09-07 0:39 ` [PATCH v3 4/4] memory-hotplug: fix pages missed by race rather than failng Minchan Kim
2012-09-07 0:39 ` Minchan Kim
2012-09-07 0:48 ` Kamezawa Hiroyuki [this message]
2012-09-07 0:48 ` Kamezawa Hiroyuki
2012-09-07 9:17 ` [PATCH v3 0/4] memory-hotplug: handle page race between allocation and isolation Mel Gorman
2012-09-07 9:17 ` Mel Gorman
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