On 01/19/2018 04:25 PM, Andrey Ryabinin wrote: > mem_cgroup_resize_[memsw]_limit() tries to free only 32 (SWAP_CLUSTER_MAX) > pages on each iteration. This makes it practically impossible to decrease > limit of memory cgroup. Tasks could easily allocate back 32 pages, so we > can't reduce memory usage, and once retry_count reaches zero we return > -EBUSY. > > Easy to reproduce the problem by running the following commands: > > mkdir /sys/fs/cgroup/memory/test > echo $$ >> /sys/fs/cgroup/memory/test/tasks > cat big_file > /dev/null & > sleep 1 && echo $((100*1024*1024)) > /sys/fs/cgroup/memory/test/memory.limit_in_bytes > -bash: echo: write error: Device or resource busy > > Instead of relying on retry_count, keep retrying the reclaim until the > desired limit is reached or fail if the reclaim doesn't make any progress > or a signal is pending. > > Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> > Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Andrew, are you ok to pick up the patch? -- 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>
