| Message ID | 20240805013019.724300-3-longman@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | cgroup/cpuset: Miscellaneous cpuset updates for 6.12 | expand |
On Sun, Aug 04, 2024 at 09:30:16PM -0400, Waiman Long wrote: > 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") > Reported-by: Chen Ridong <chenridong@huawei.com> > Signed-off-by: Waiman Long <longman@redhat.com> Applied 1-2 to cgroup/for-6.11-fixes w/ stable cc'd. Thanks.
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index f1846a08e245..7287cecb27d1 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2508,7 +2508,8 @@ 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)
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") Reported-by: Chen Ridong <chenridong@huawei.com> Signed-off-by: Waiman Long <longman@redhat.com> --- kernel/cgroup/cpuset.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)