Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH 1/2] sched/wait: Break up long wake list walk | Date | Fri, 18 Aug 2017 16:53:30 +0000 |
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> On Fri, Aug 18, 2017 at 02:20:38PM +0000, Liang, Kan wrote: > > > Nothing fancy other than needing a comment if it works. > > > > > > > No, the patch doesn't work. > > > > That indicates that it may be a hot page and it's possible that the page is > locked for a short time but waiters accumulate. What happens if you leave > NUMA balancing enabled but disable THP?
No, disabling THP doesn't help the case.
Thanks, Kan
> Waiting on migration entries also > uses wait_on_page_locked so it would be interesting to know if the problem > is specific to THP. > > Can you tell me what this workload is doing? I want to see if it's something > like many threads pounding on a limited number of pages very quickly. If it's > many threads working on private data, it would also be important to know > how each buffers threads are aligned, particularly if the buffers are smaller > than a THP or base page size. For example, if each thread is operating on a > base page sized buffer then disabling THP would side-step the problem but > THP would be false sharing between multiple threads. > > > -- > Mel Gorman > SUSE Labs
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