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Date: Tue, 12 May 2009 08:48:42 +0900
Message-ID: <28c262360905111648p21628f74u37daf0b028fe3fca@mail.gmail.com>
Subject: Re: [patch -mmotm] mm: invoke oom killer for __GFP_NOFAIL
From: Minchan Kim <minchan.kim@gmail.com>
To: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>, Andrew Morton <akpm@linux-foundation.org>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>, Nick Piggin <npiggin@suse.de>,
       Christoph Lameter <cl@linux-foundation.org>,
       Dave Hansen <dave@linux.vnet.ibm.com>, linux-kernel@vger.kernel.org
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On Tue, May 12, 2009 at 4:32 AM, David Rientjes <rientjes@google.com> wrote:
> On Mon, 11 May 2009, Minchan Kim wrote:
>
>> But this patch increases the probability of innocent task killing.
>> Is GFP_NOFAIL's early bailout more important than killing of innocent task ?
>>
>
> __GFP_NOFAIL's bailout is, by definition, a bug in the page allocator and
> this patch fixes it.
>

What I mean is If fortunately other process have a lot of memory is
exited while looping, __GFP_NOFAIL can return.
I have no objection about your patch.
Just, I have a concern of killing innocent task.

As Mel and Andrew pointed out, fundamentally, __GFOP_NOFAIL and
high-order allocation itself is bad code.
Okay. we have to insert WARN_ON properly.

Thanks for good contribution. :)

-- 
Kinds regards,
Minchan Kim