Re: [PATCH 0/3] OOM detection rework v4

[Vlastimil Babka]

On 03/03/2016 09:57 PM, Hugh Dickins wrote:
> 
>>
>> I do not have an explanation why it would cause oom sooner but this
>> turned out to be incomplete. There is another wmaark check deeper in the
>> compaction path. Could you try the one from
>> http://lkml.kernel.org/r/20160302130022.GG26686@xxxxxxxxxxxxxx
> 
> I've now added that in: it corrects the "sooner", but does not make
> any difference to the fact of OOMing for me.

Could you try producing a trace with
echo 1 > /debug/tracing/events/compaction/enable
echo 1 > /debug/tracing/events/migrate/mm_migrate_pages/enable

Hopefully it will hint at what's wrong with:
compact_migrate_scanned 424920
compact_free_scanned 9278408
compact_isolated 469472
compact_stall 377
compact_fail 297
compact_success 80
compact_kcompatd_wake 0