Waiman Long 2125c0034c cgroup/cpuset: Make cpuset hotplug processing synchronous ... Since commit 3a5a6d0c2b03("cpuset: don't nest cgroup_mutex inside get_online_cpus()"), cpuset hotplug was done asynchronously via a work function. This is to avoid recursive locking of cgroup_mutex. Since then, the cgroup locking scheme has changed quite a bit. A cpuset_mutex was introduced to protect cpuset specific operations. The cpuset_mutex is then replaced by a cpuset_rwsem. With commit d74b27d63a ("cgroup/cpuset: Change cpuset_rwsem and hotplug lock order"), cpu_hotplug_lock is acquired before cpuset_rwsem. Later on, cpuset_rwsem is reverted back to cpuset_mutex. All these locking changes allow the hotplug code to call into cpuset core directly. The following commits were also merged due to the asynchronous nature of cpuset hotplug processing. - commit b22afcdf04 ("cpu/hotplug: Cure the cpusets trainwreck") - commit 50e7663233 ("sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs") - commit 28b89b9e6f ("cpuset: handle race between CPU hotplug and cpuset_hotplug_work") Clean up all these bandages by making cpuset hotplug processing synchronous again with the exception that the call to cgroup_transfer_tasks() to transfer tasks out of an empty cgroup v1 cpuset, if necessary, will still be done via a work function due to the existing cgroup_mutex -> cpu_hotplug_lock dependency. It is possible to reverse that dependency, but that will require updating a number of different cgroup controllers. This special hotplug code path should be rarely taken anyway. As all the cpuset states will be updated by the end of the hotplug operation, we can revert most the above commits except commit 50e7663233 ("sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs") which is partially reverted. Also removing some cpus_read_lock trylock attempts in the cpuset partition code as they are no longer necessary since the cpu_hotplug_lock is now held for the whole duration of the cpuset hotplug code path. Signed-off-by: Waiman Long <longman@redhat.com> Tested-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>		2024-04-08 07:39:16 -10:00
..
cgroup-internal.h	cgroup: Add a new helper for cgroup1 hierarchy	2023-11-09 13:25:47 -10:00
cgroup-v1.c	Driver core changes for 6.8-rc1	2024-01-18 09:48:40 -08:00
cgroup.c	Driver core changes for 6.8-rc1	2024-01-18 09:48:40 -08:00
cpuset.c	cgroup/cpuset: Make cpuset hotplug processing synchronous	2024-04-08 07:39:16 -10:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: cleanup comments	2022-03-13 19:19:27 -10:00
legacy_freezer.c	cgroup_freezer: cgroup_freezing: Check if not frozen	2023-11-28 08:04:03 -10:00
Makefile	cgroup: Add misc cgroup controller	2021-04-04 13:34:46 -04:00
misc.c	cgroup/misc: Store atomic64_t reads to u64	2023-07-21 08:10:06 -10:00
namespace.c	cgroup:namespace: Remove unused cgroup_namespaces_init()	2023-08-14 14:29:47 -10:00
pids.c	cgroup: add pids.peak interface for pids controller	2022-09-04 09:26:51 -10:00
rdma.c	rdmacg: fix kernel-doc warnings in rdmacg	2023-06-05 09:45:14 -10:00
rstat.c	bpf: treewide: Annotate BPF kfuncs in BTF	2024-01-31 20:40:56 -08:00