Tejun Heo 6a010a49b6 cgroup: Make !percpu threadgroup_rwsem operations optional ... 3942a9bd7b ("locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem because the impiled synchronize_rcu() on write locking was pushing up the latencies too much for android which constantly moves processes between cgroups. This makes the hotter paths - fork and exit - slower as they're always forced into the slow path. There is no reason to force this on everyone especially given that more common static usage pattern can now completely avoid write-locking the rwsem. Write-locking is elided when turning on and off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a cgroup without grabbing the rwsem. Restore the default percpu operations and introduce the mount option "favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need lower latencies for the dynamic operations. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Michal Koutn� <mkoutny@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Oleg Nesterov <oleg@redhat.com>		2022-07-23 04:29:02 -10:00
..
cgroup-internal.h	cgroup: Make !percpu threadgroup_rwsem operations optional	2022-07-23 04:29:02 -10:00
cgroup-v1.c	cgroup: Make !percpu threadgroup_rwsem operations optional	2022-07-23 04:29:02 -10:00
cgroup.c	cgroup: Make !percpu threadgroup_rwsem operations optional	2022-07-23 04:29:02 -10:00
cpuset.c	cgroup/cpuset: Remove cpus_allowed/mems_allowed setup in cpuset_init_smp()	2022-05-05 08:57:00 -10:00
debug.c
freezer.c	cgroup: cleanup comments	2022-03-13 19:19:27 -10:00
legacy_freezer.c
Makefile	cgroup: Add misc cgroup controller	2021-04-04 13:34:46 -04:00
misc.c	misc_cgroup: remove error log to avoid log flood	2021-09-20 07:35:38 -10:00
namespace.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
pids.c	clone3: allow spawning processes into cgroups	2020-02-12 17:57:51 -05:00
rdma.c	cgroup: fix spelling mistakes	2021-05-24 12:45:26 -04:00
rstat.c	Merge branch 'akpm' (patches from Andrew)	2022-03-24 14:14:07 -07:00