Re: readahead and oom

From: Pekka Enberg
Date: Tue Apr 26 2011 - 06:19:00 EST


On Tue, Apr 26, 2011 at 12:28 PM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote:
> On Tue, Apr 26, 2011 at 6:20 PM, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote:
>> Minchan,
>>
>>> > +static inline struct page *page_cache_alloc_cold_noretry(struct address_space *x)
>>> > +{
>>> > +       return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD|__GFP_NORETRY);
>>>
>>> It makes sense to me but it could make a noise about page allocation
>>> failure. I think it's not desirable.
>>> How about adding __GFP_NOWARAN?
>>
>> Yeah it makes sense. Here is the new version.
>>
>> Thanks,
>> Fengguang
>> ---
>> Subject: readahead: readahead page allocations is OK to fail
>> Date: Tue Apr 26 14:29:40 CST 2011
>>
>> Pass __GFP_NORETRY|__GFP_NOWARN for readahead page allocations.
>>
>> readahead page allocations are completely optional. They are OK to
>> fail and in particular shall not trigger OOM on themselves.
>>
>> Reported-by: Dave Young <hidave.darkstar@xxxxxxxxx>
>> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
>> Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>

Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
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