Hello. I have a setup where web server processes start, fork on http requests (on almost each request) and then migrate to cgroup (different one depending on request) by writting to proper cgroup.procs, doing web server job and exiting. Using kernel 4.19.13. For one cgroup I noticed weird behaviour: # cat pids.current 60 # cat cgroup.procs # There are no processes, yet kernel tells me that there 60 of these. And such state is for hours. Now if some process gets migrated to that cgroup then pids.current starts showing 61 but never goes to 0. Tasks from that cgroup were killed by OOM once, so - could be there some bug related to memory.oom.group handling? (previously wasn't using memory.oom.group and didn't notice any problems with pids.current) cgroup.controllers:io memory pids cgroup.events:populated 0 cgroup.max.depth:max cgroup.max.descendants:max cgroup.stat:nr_descendants 0 cgroup.stat:nr_dying_descendants 0 cgroup.type:domain cpu.stat:usage_usec 12187745302 cpu.stat:user_usec 9417005001 cpu.stat:system_usec 2770740301 io.stat:254:1 rbytes=214016 wbytes=283648 rios=18 wios=21 dbytes=0 dios=0 io.stat:8:0 rbytes=850417664 wbytes=1073743360 rios=64260 wios=52463 dbytes=0 dios=0 io.stat:254:0 rbytes=801071616 wbytes=1067499008 rios=60129 wios=52007 dbytes=0 dios=0 io.weight:default 100 memory.current:83976192 memory.events:low 0 memory.events:high 0 memory.events:max 179 memory.events:oom 4 memory.events:oom_kill 61 memory.high:max memory.low:0 memory.max:2147483648 memory.min:0 memory.oom.group:1 memory.stat:anon 425984 memory.stat:file 72691712 memory.stat:kernel_stack 49152 memory.stat:slab 10395648 memory.stat:sock 65536 memory.stat:shmem 0 memory.stat:file_mapped 540672 memory.stat:file_dirty 405504 memory.stat:file_writeback 405504 memory.stat:inactive_anon 0 memory.stat:active_anon 0 memory.stat:inactive_file 14659584 memory.stat:active_file 58421248 memory.stat:unevictable 0 memory.stat:slab_reclaimable 5427200 memory.stat:slab_unreclaimable 4968448 memory.stat:pgfault 83157624 memory.stat:pgmajfault 39699 memory.stat:pgrefill 82897 memory.stat:pgscan 94631 memory.stat:pgsteal 93886 memory.stat:pgactivate 99 memory.stat:pgdeactivate 82897 memory.stat:pglazyfree 0 memory.stat:pglazyfreed 0 memory.stat:workingset_refault 7029 memory.stat:workingset_activate 4059 memory.stat:workingset_nodereclaim 0 memory.swap.current:0 memory.swap.events:max 0 memory.swap.events:fail 0 memory.swap.max:max pids.current:60 pids.events:max 0 pids.max:60 -- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )
