On Tue, Feb 22, 2022 at 12:27:31PM -0500, Shuang Zhai wrote: > Mel Gorman wrote: > > On Mon, Feb 14, 2022 at 04:10:50PM -0500, Shuang Zhai wrote: > > > Hi Mel, > > > > > > Mel Gorman wrote: > > > > > > > > Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar > > > > problems due to reclaim throttling for excessive lengths of time. > > > > In Alexey's case, a memory hog that should go OOM quickly stalls for > > > > several minutes before stalling. In Mike and Darrick's cases, a small > > > > memcg environment stalled excessively even though the system had enough > > > > memory overall. > > > > > > > > > > I recently found a regression when I tested MGLRU with fio on Linux > > > 5.16-rc6 [1]. After this patch was applied, I re-ran the test with Linux > > > 5.16, but the regression has not been fixed yet. > > > > > > > Am I correct in thinging that this only happens with MGLRU? > > Sorry about the confusion and let me clarify on this. The regression happens > on upstream Linux with the default page replacement mechanism. Ok, the fio command for me simply exits with an error and even if it didn't the test machine I have with persistent memory does not have enough pmem to trigger memory reclaim issues with fio. Can you do the following please? # echo 1 > vmscan/mm_vmscan_throttled/enable # cat /sys/kernel/debug/tracing/trace_pipe > trace.out and run the test? Compress trace.out with xz and send it to me by mail. If the trace is too large, send as much as you can. -- Mel Gorman SUSE Labs
