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 <[email protected]> > Cc: Shakeel Butt <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Johannes Weiner <[email protected]> > Cc: Vladimir Davydov <[email protected]>
Andrew, are you ok to pick up the patch?
