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Date: Tue, 12 Jan 2010 23:46:38 +0900
Message-ID: <28c262361001120646y6f3603b8q236d0a7c02250ffa@mail.gmail.com>
Subject: Re: [resend][PATCH] mm, lockdep: annotate reclaim context to zone 
	reclaim too
From: Minchan Kim <minchan.kim@gmail.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>,
       Nick Piggin <npiggin@suse.de>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Ingo Molnar <mingo@elte.hu>
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On Tue, Jan 12, 2010 at 2:16 PM, KOSAKI Motohiro
<kosaki.motohiro@jp.fujitsu.com> wrote:
>
> Commit cf40bd16fd (lockdep: annotate reclaim context) introduced reclaim
> context annotation. But it didn't annotate zone reclaim. This patch do it.
>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> Cc: Nick Piggin <npiggin@suse.de>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>

I think your good explanation in previous thread is good for
changelog. so I readd in here.
If you mind this, feel free to discard.
I don't care about it. :)

---

<kosaki.motohiro@jp.fujitsu.com> wrote:
The point is zone-reclaim doesn't use
__alloc_pages_direct_reclaim.
current call graph is

__alloc_pages_nodemask
   get_page_from_freelist
       zone_reclaim()
   __alloc_pages_slowpath
       __alloc_pages_direct_reclaim
           try_to_free_pages

Actually, if zone_reclaim_mode=1, VM never call
__alloc_pages_direct_reclaim in usual VM pressure.
Thus I think zone-reclaim should be annotated explicitly too.
I know almost user don't use zone reclaim mode. but explicit
annotation doesn't have any demerit, I think.

-- 
Kind regards,
Minchan Kim