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Date: Sat, 7 Nov 2009 04:20:51 +0900 (JST)
Subject: Re: [MM] Make mm counters per cpu instead of atomic V2
From: "KAMEZAWA Hiroyuki" <kamezawa.hiroyu@jp.fujitsu.com>
To: "Christoph Lameter" <cl@linux-foundation.org>
Cc: "KAMEZAWA Hiroyuki" <kamezawa.hiroyu@jp.fujitsu.com>,
       "Dave Jones" <davej@redhat.com>,
       "hugh.dickins@tiscali.co.uk" <hugh.dickins@tiscali.co.uk>,
       linux-mm@kvack.org, linux-kernel@vger.kernel.org,
       akpm@linux-foundation.org, "Tejun Heo" <tj@kernel.org>
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Christoph Lameter wrote:
> On Sat, 7 Nov 2009, KAMEZAWA Hiroyuki wrote:
>
>> And allocate mm->usage only when the first CLONE_THREAD is specified.
>
> Ok.
>
>> if (mm->usage)
>>     access per cpu
>> else
>>     atomic_long_xxx
>
> If we just have one thread: Do we need atomic access at all?
>
Unfortunately, kswapd/vmscan touch this.

Thanks,
-Kame


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