Re: [cgroup/for-6.20 PATCH v2 1/4] cgroup/cpuset: Streamline rm_siblings_excl_cpus()

On 2026/1/2 3:15, Waiman Long wrote:

If exclusive_cpus is set, effective_xcpus must be a subset of exclusive_cpus. Currently, rm_siblings_excl_cpus() checks both exclusive_cpus and effective_xcpus consecutively. It is simpler to check only exclusive_cpus if non-empty or just effective_xcpus otherwise.

No functional change is expected.

Signed-off-by: Waiman Long longman@redhat.com

kernel/cgroup/cpuset.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 221da921b4f9..da2b3b51630e 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1355,23 +1355,29 @@ static int rm_siblings_excl_cpus(struct cpuset *parent, struct cpuset *cs, int retval = 0; if (cpumask_empty(excpus))

• return retval;
  

• return 0;
  

/*

• * Exclude exclusive CPUs from siblings
  

• * Remove exclusive CPUs from siblings
  

  */ rcu_read_lock(); cpuset_for_each_child(sibling, css, parent) {

• struct cpumask *sibling_xcpus;
  

• if (sibling == cs) continue;

• if (cpumask_intersects(excpus, sibling->exclusive_cpus)) {
  

• 	cpumask_andnot(excpus, excpus, sibling->exclusive_cpus);
  

• 	retval++;
  

• 	continue;
  

• }
  

• if (cpumask_intersects(excpus, sibling->effective_xcpus)) {
  

• 	cpumask_andnot(excpus, excpus, sibling->effective_xcpus);
  

• /*
  

•  * If exclusive_cpus is defined, effective_xcpus will always
  

•  * be a subset. Otherwise, effective_xcpus will only be set
  

•  * in a valid partition root.
  

•  */
  

• sibling_xcpus = cpumask_empty(sibling->exclusive_cpus)
  

• 	      ? sibling->effective_xcpus
  

• 	      : sibling->exclusive_cpus;
  

• if (cpumask_intersects(excpus, sibling_xcpus)) {
  

• 	cpumask_andnot(excpus, excpus, sibling_xcpus);
  retval++;
  

  } }

LGTM

Reviewed-by: Chen Ridongchenridong@huawei.com