Messages in this thread | | | From | Shakeel Butt <> | Date | Tue, 9 Jan 2018 09:22:53 -0800 | Subject | Re: [PATCH v3 1/2] mm/memcg: try harder to decrease [memory,memsw].limit_in_bytes |
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On Tue, Jan 9, 2018 at 8:58 AM, Andrey Ryabinin <aryabinin@virtuozzo.com> wrote: > mem_cgroup_resize_[memsw]_limit() tries to free only 32 (SWAP_CLUSTER_MAX) > pages on each iteration. This makes 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@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
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