Michal Hocko 86327e8eb9 memcg: drop kmem.limit_in_bytes ... kmem.limit_in_bytes (v1 way to limit kernel memory usage) has been deprecated since 58056f7750 ("memcg, kmem: further deprecate kmem.limit_in_bytes") merged in 5.16. We haven't heard about any serious users since then but it seems that the mere presence of the file is causing more harm thatn good. We (SUSE) have had several bug reports from customers where Docker based containers started to fail because a write to kmem.limit_in_bytes has failed. This was unexpected because runc code only expects ENOENT (kmem disabled) or EBUSY (tasks already running within cgroup). So a new error code was unexpected and the whole container startup failed. This has been later addressed by 52390d6804 so current Docker runtimes do not suffer from the problem anymore. There are still older version of Docker in use and likely hard to get rid of completely. Address this by wiping out the file completely and effectively get back to pre 4.5 era and CONFIG_MEMCG_KMEM=n configuration. I would recommend backporting to stable trees which have picked up 58056f7750 ("memcg, kmem: further deprecate kmem.limit_in_bytes"). [mhocko@suse.com: restore _KMEM switch case] Link: https://lkml.kernel.org/r/ZKe5wxdbvPi5Cwd7@dhcp22.suse.cz Link: https://lkml.kernel.org/r/20230704115240.14672-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2023-08-18 10:12:11 -07:00
..
blkio-controller.rst	Documentation: admin-guide: correct spelling	2023-02-02 11:04:42 -07:00
cgroups.rst	docs: cgroup-v1: use numbered lists for user interface setup	2023-01-05 07:38:11 -10:00
cpuacct.rst
cpusets.rst	docs: cgroup-v1/cpusets: update libcgroup project link	2023-04-14 06:55:48 -10:00
devices.rst
freezer-subsystem.rst
hugetlb.rst	hugetlb: add hugetlb.*.numa_stat file	2022-01-15 16:30:29 +02:00
index.rst	cgroup: Miscellaneous cgroup documentation.	2021-04-04 13:34:46 -04:00
memcg_test.rst	filemap: Remove add_to_page_cache() and add_to_page_cache_locked()	2022-06-29 08:51:05 -04:00
memory.rst	memcg: drop kmem.limit_in_bytes	2023-08-18 10:12:11 -07:00
misc.rst	cgroup: Miscellaneous cgroup documentation.	2021-04-04 13:34:46 -04:00
net_cls.rst
net_prio.rst
pids.rst
rdma.rst	Documentation/admin-guide: cgroup-v1/rdma: drop doubled word	2020-07-05 14:01:48 -06:00