diff options
| author | Waiman Long | 2024-08-04 21:30:16 -0400 |
|---|---|---|
| committer | Tejun Heo | 2024-08-05 10:52:40 -1000 |
| commit | 311a1bdc44a8e06024df4fd3392be0dfc8298655 (patch) | |
| tree | 4a13485e4e3e5a6308af1c9053144de4b8ec72ae | |
| parent | 959ab6350add903e352890af53e86663739fcb9a (diff) | |
cgroup/cpuset: Clear effective_xcpus on cpus_allowed clearing only if cpus.exclusive not set
Commit e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for
v2") adds a user writable cpuset.cpus.exclusive file for setting
exclusive CPUs to be used for the creation of partitions. Since then
effective_xcpus depends on both the cpuset.cpus and cpuset.cpus.exclusive
setting. If cpuset.cpus.exclusive is set, effective_xcpus will depend
only on cpuset.cpus.exclusive. When it is not set, effective_xcpus
will be set according to the cpuset.cpus value when the cpuset becomes
a valid partition root.
When cpuset.cpus is being cleared by the user, effective_xcpus should
only be cleared when cpuset.cpus.exclusive is not set. However, that
is not currently the case.
# cd /sys/fs/cgroup/
# mkdir test
# echo +cpuset > cgroup.subtree_control
# cd test
# echo 3 > cpuset.cpus.exclusive
# cat cpuset.cpus.exclusive.effective
3
# echo > cpuset.cpus
# cat cpuset.cpus.exclusive.effective // was cleared
Fix it by clearing effective_xcpus only if cpuset.cpus.exclusive is
not set.
Fixes: e2ffe502ba45 ("cgroup/cpuset: Add cpuset.cpus.exclusive for v2")
Cc: stable@vger.kernel.org # v6.7+
Reported-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | kernel/cgroup/cpuset.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index a9b6d56eeffa..97d02612b3a6 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2525,7 +2525,8 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, */ if (!*buf) { cpumask_clear(trialcs->cpus_allowed); - cpumask_clear(trialcs->effective_xcpus); + if (cpumask_empty(trialcs->exclusive_cpus)) + cpumask_clear(trialcs->effective_xcpus); } else { retval = cpulist_parse(buf, trialcs->cpus_allowed); if (retval < 0) |