From: Wen Congyang <wency@cn.fujitsu.com>
To: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
Shaohua Li <shli@fusionio.com>
Subject: Re: [PATCH] memory-hotplug: fix zone stat mismatch
Date: Thu, 20 Sep 2012 09:17:43 +0800 [thread overview]
Message-ID: <505A6EB7.5070305@cn.fujitsu.com> (raw)
In-Reply-To: <20120919201738.GA2425@barrios>
At 09/20/2012 04:17 AM, Minchan Kim Wrote:
> Hi KOSAKI,
>
> On Wed, Sep 19, 2012 at 02:05:20PM -0400, KOSAKI Motohiro wrote:
>> On Wed, Sep 19, 2012 at 3:29 AM, Minchan Kim <minchan@kernel.org> wrote:
>>> During memory-hotplug stress test, I found NR_ISOLATED_[ANON|FILE]
>>> are increasing so that kernel are hang out.
>>>
>>> The cause is that when we do memory-hotadd after memory-remove,
>>> __zone_pcp_update clear out zone's ZONE_STAT_ITEMS in setup_pageset
>>> without draining vm_stat_diff of all CPU.
>>>
>>> This patch fixes it.
>>
>> zone_pcp_update() is called from online pages path. but IMHO,
>> the statistics should be drained offline path. isn't it?
>
> It isn't necessary because statistics is right until we reset it to zero
> in online path.
> Do you have something on your mind that we have to drain it in offline path?
When a node is offlined and onlined again. We create node_data[i] in the
function hotadd_new_pgdat(), and we will lost the statistics stored in
zone->pageset. So we should drain it in offline path.
Thanks
Wen Congyang
>
>>
>> thanks.
>
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WARNING: multiple messages have this Message-ID (diff)
From: Wen Congyang <wency@cn.fujitsu.com>
To: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
Shaohua Li <shli@fusionio.com>
Subject: Re: [PATCH] memory-hotplug: fix zone stat mismatch
Date: Thu, 20 Sep 2012 09:17:43 +0800 [thread overview]
Message-ID: <505A6EB7.5070305@cn.fujitsu.com> (raw)
In-Reply-To: <20120919201738.GA2425@barrios>
At 09/20/2012 04:17 AM, Minchan Kim Wrote:
> Hi KOSAKI,
>
> On Wed, Sep 19, 2012 at 02:05:20PM -0400, KOSAKI Motohiro wrote:
>> On Wed, Sep 19, 2012 at 3:29 AM, Minchan Kim <minchan@kernel.org> wrote:
>>> During memory-hotplug stress test, I found NR_ISOLATED_[ANON|FILE]
>>> are increasing so that kernel are hang out.
>>>
>>> The cause is that when we do memory-hotadd after memory-remove,
>>> __zone_pcp_update clear out zone's ZONE_STAT_ITEMS in setup_pageset
>>> without draining vm_stat_diff of all CPU.
>>>
>>> This patch fixes it.
>>
>> zone_pcp_update() is called from online pages path. but IMHO,
>> the statistics should be drained offline path. isn't it?
>
> It isn't necessary because statistics is right until we reset it to zero
> in online path.
> Do you have something on your mind that we have to drain it in offline path?
When a node is offlined and onlined again. We create node_data[i] in the
function hotadd_new_pgdat(), and we will lost the statistics stored in
zone->pageset. So we should drain it in offline path.
Thanks
Wen Congyang
>
>>
>> thanks.
>
next prev parent reply other threads:[~2012-09-20 1:12 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-19 7:29 [PATCH] memory-hotplug: fix zone stat mismatch Minchan Kim
2012-09-19 7:29 ` Minchan Kim
2012-09-19 18:05 ` KOSAKI Motohiro
2012-09-19 18:05 ` KOSAKI Motohiro
2012-09-19 20:17 ` Minchan Kim
2012-09-19 20:17 ` Minchan Kim
2012-09-20 1:17 ` Wen Congyang [this message]
2012-09-20 1:17 ` Wen Congyang
2012-09-20 2:30 ` Minchan Kim
2012-09-20 2:30 ` Minchan Kim
2012-09-20 3:12 ` Wen Congyang
2012-09-20 3:12 ` Wen Congyang
2012-09-20 5:16 ` Minchan Kim
2012-09-20 5:16 ` Minchan Kim
2012-09-20 5:22 ` Wen Congyang
2012-09-20 5:22 ` Wen Congyang
2012-09-20 5:32 ` Wen Congyang
2012-09-20 5:32 ` Wen Congyang
2012-09-20 5:55 ` Minchan Kim
2012-09-20 5:55 ` Minchan Kim
2012-09-20 6:17 ` Wen Congyang
2012-09-20 6:17 ` Wen Congyang
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