On Wednesday 17 of August 2016, Michal Hocko wrote: > On Wed 17-08-16 10:34:54, Arkadiusz Miśkiewicz wrote: > [...] > > > With "[PATCH] mm, oom: report compaction/migration stats for higher order > > requests" patch: > > https://ixion.pld-linux.org/~arekm/p2/ext4/log-20160817.txt > > > > Didn't count much - all counters are 0 > > compaction_stall:0 compaction_fail:0 compact_migrate_scanned:0 > > compact_free_scanned:0 compact_isolated:0 pgmigrate_success:0 > > pgmigrate_fail:0 > > Dohh, COMPACTION counters are events and those are different than other > counters we have. They only have per-cpu representation and so we would > have to do > + for_each_online_cpu(cpu) { > + struct vm_event_state *this = &per_cpu(vm_event_states, > cpu); + ret += this->event[item]; > + } > > which is really nasty because, strictly speaking, we would have to do > {get,put}_online_cpus around that loop and that uses locking and we do > not want to possibly block in this path just because something is in the > middle of the hotplug. So let's scratch that patch for now and sorry I > haven't realized that earlier. > > > two processes were killed by OOM (rm and cp), the rest of rm/cp didn't > > finish > > > > and I'm interrupting it to try that next patch: > > > Could you try to test with > > > patch from > > > http://lkml.kernel.org/r/20160816031222.GC16913@js1304-P5Q-DELUXE > > > please? Ideally on top of linux-next. You can add both the compaction > > > counters patch in the oom report and high order atomic reserves patch > > > on top. > > > > Uhm, was going to use it on top of 4.7.[01] first. > > OK So with http://lkml.kernel.org/r/20160816031222.GC16913@js1304-P5Q-DELUXE OOM no longer happens (all 10x rm/cp processes finished). https://ixion.pld-linux.org/~arekm/p2/ext4/log-20160818.txt On Wednesday 17 of August 2016, Jan Kara wrote: > Just one more debug idea to add on top of what Michal said: Can you enable > mm_shrink_slab_start and mm_shrink_slab_end tracepoints (via > /sys/kernel/debug/tracing/events/vmscan/mm_shrink_slab_{start,end}/enable) > and gather output from /sys/kernel/debug/tracing/trace_pipe while the copy > is running? Here it is: https://ixion.pld-linux.org/~arekm/p2/ext4/log-trace_pipe-20160818.txt.gz -- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org ) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
