Waiman Long 8e1716993b cgroup/cpuset: Remove cpus_allowed/mems_allowed setup in cpuset_init_smp() ... commit 2685027fca upstream. There are 3 places where the cpu and node masks of the top cpuset can be initialized in the order they are executed: 1) start_kernel -> cpuset_init() 2) start_kernel -> cgroup_init() -> cpuset_bind() 3) kernel_init_freeable() -> do_basic_setup() -> cpuset_init_smp() The first cpuset_init() call just sets all the bits in the masks. The second cpuset_bind() call sets cpus_allowed and mems_allowed to the default v2 values. The third cpuset_init_smp() call sets them back to v1 values. For systems with cgroup v2 setup, cpuset_bind() is called once. As a result, cpu and memory node hot add may fail to update the cpu and node masks of the top cpuset to include the newly added cpu or node in a cgroup v2 environment. For systems with cgroup v1 setup, cpuset_bind() is called again by rebind_subsystem() when the v1 cpuset filesystem is mounted as shown in the dmesg log below with an instrumented kernel. [ 2.609781] cpuset_bind() called - v2 = 1 [ 3.079473] cpuset_init_smp() called [ 7.103710] cpuset_bind() called - v2 = 0 smp_init() is called after the first two init functions. So we don't have a complete list of active cpus and memory nodes until later in cpuset_init_smp() which is the right time to set up effective_cpus and effective_mems. To fix this cgroup v2 mask setup problem, the potentially incorrect cpus_allowed & mems_allowed setting in cpuset_init_smp() are removed. For cgroup v2 systems, the initial cpuset_bind() call will set the masks correctly. For cgroup v1 systems, the second call to cpuset_bind() will do the right setup. cc: stable@vger.kernel.org Signed-off-by: Waiman Long <longman@redhat.com> Tested-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-05-18 10:26:56 +02:00
..
Makefile	cgroup: Add misc cgroup controller	2021-04-04 13:34:46 -04:00
cgroup-internal.h	cgroup: Use open-time cgroup namespace for process migration perm checks	2022-01-11 15:35:15 +01:00
cgroup-v1.c	cgroup-v1: Correct privileges check in release_agent writes	2022-03-02 11:47:47 +01:00
cgroup.c	psi: Fix uaf issue when psi trigger is destroyed while being polled	2022-02-01 17:27:01 +01:00
cpuset.c	cgroup/cpuset: Remove cpus_allowed/mems_allowed setup in cpuset_init_smp()	2022-05-18 10:26:56 +02:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: freezer: don't change task and cgroups status unnecessarily	2019-11-07 07:38:41 -08:00
legacy_freezer.c	cgroup: rename freezer.c into legacy_freezer.c	2019-04-19 11:26:48 -07:00
misc.c	svm/sev: Register SEV and SEV-ES ASIDs to the misc controller	2021-04-04 13:34:46 -04:00
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	cgroup: Fix rootcg cpu.stat guest double counting	2021-11-18 19:16:45 +01:00