Re: [PATCH 0/5] Candidate fix for increased number of GFP_ATOMIC failures V2

[Mel LKML]

Hi,

This is the same Mel as mel@xxxxxxxxxx The mail server the address is
on has no power until Tuesday so I'm not going to be very unresponsive
until then. Monday is also a public holiday here and apparently they
are upgrading the power transformers near the building.

On 10/23/09, Karol Lewandowski <karol.k.lewandowski@xxxxxxxxx> wrote:
> On Fri, Oct 23, 2009 at 06:58:10PM +0200, Karol Lewandowski wrote:
>> On Thu, Oct 22, 2009 at 03:22:31PM +0100, Mel Gorman wrote:
>> > Test 3: If you are getting allocation failures, try with the following
>> > patch
>> >
>> >   3/5 vmscan: Force kswapd to take notice faster when high-order
>> > watermarks are being hit
>
>> No, problem doesn't go away with these patches (1+2+3).  However, from
>> my testing this particular patch makes it way, way harder to trigger
>> allocation failures (but these are still present).
>>
>> This bothers me - should I test following patches with or without
>> above patch?  This patch makes bug harder to find, IMVHO it doesn't
>> fix the real problem.
> ..
>
>> Test 4: If you are still getting failures, apply the following
>>  4/5 page allocator: Pre-emptively wake kswapd when high-order watermarks
>> are hit
>
> Ok, I've tested patches 1+2+4 and bug, while very hard to trigger, is
> still present. I'll test complete 1-4 patchset as time permits.
>

And also patch 5 please which is the revert. Patch 5 as pointed out is
probably a red herring. Hwoever, it has changed the timing and made a
difference for some testing so I'd like to know if it helps yours as
well.

As things stand, it looks like patches 1+2 should certainly go ahead.
I need to give more thought on patches 3 and 4 as to why they help
Tobias but not anyone elses testing.

Thanks
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