On Wed, Jul 20, 2016 at 09:16:24AM +0900, Minchan Kim wrote: > On Tue, Jul 19, 2016 at 05:48:57PM +0100, Mel Gorman wrote: > > On Wed, Jul 20, 2016 at 12:50:32AM +0900, Minchan Kim wrote: > > > While I did stress test with hackbench, I got OOM message frequently > > > which didn't ever happen in zone-lru. > > > > > > > This one also showed pgdat going unreclaimable early. Have you tried any > > of the three oom-related patches I sent to Joonsoo to see what impact, > > if any, it had? > > Before the result, I want to say goal of this patch, again. > Without per-zone lru stat, it's really hard to debug OOM problem in > multiple zones system so regardless of solving the problem, we should add > per-zone lru stat for debuggability of OOM which has been never perfect > solution, ever. > That's not in dispute, I simply wanted to know the impact. > The result is not OOM but hackbench stalls forever. Ok, that points to both the premature marking pgdats as unreclaimable and the inactive rotation are both problems. I have a series prepared that may or may not address the problem. I'm trying to reproduce the OOM killer on a 32-bit KVM but so far so luck. If I fail to reproduce it then I cannot tell if the series has an impact and may have to post it and hope you and Joonsoo can test it. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>