cgroup, sched: deprecate cpuacct
Now that cpu serves the same files as cpuacct and using cpuacct
separately from cpu is deprecated, we can deprecate cpuacct. To avoid
disturbing userland which has been co-mounting cpu and cpuacct,
implement some hackery in cgroup core so that cpuacct co-mounting
still works even if cpuacct is disabled.
The goal of this patch is to accelerate disabling and removal of
cpuacct by decoupling kernel-side deprecation from userland changes.
Userland is recommended to do the following.
* If /proc/cgroups lists cpuacct, always co-mount it with cpu under
e.g. /sys/fs/cgroup/cpu.
* Optionally create symlinks for compatibility -
e.g. /sys/fs/cgroup/cpuacct and /sys/fs/cgroup/cpu,cpucct both
pointing to /sys/fs/cgroup/cpu - whether cpuacct exists or not.
This compatibility hack will eventually go away.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Dave Jones <davej@redhat.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Paul Turner <pjt@google.com>
3 files changed
