On Thu 05-05-16 17:25:07, Odzioba, Lukasz wrote: > On Thu 05-05-16 09:21:00, Michal Hocko wrote: > > OK, it wasn't that tricky afterall. Maybe I have missed something but > > the following should work. Or maybe the async nature of flushing turns > > out to be just impractical and unreliable and we will end up skipping > > THP (or all compound pages) for pcp LRU add cache. Let's see... > > Initially this issue was found on RH's 3.10.x kernel, but now I am using > 4.6-rc6. > > In overall it does help and under heavy load it is slightly better than the > second patch. Unfortunately I am still able to hit 10-20% oom kills with it - > (went down from 30-50%) partially due to earlier vmstat_update call > - it went up to 25-25% with this patch below:
This simply shows that this is not a viable option. So I guess we really want to rather skip THP (compound pages) from LRU add pcp cache. Thanks for your effort and testing! -- Michal Hocko SUSE Labs
