cgroup/cpuset: Consistently compute effective_xcpus in update_cpumasks_hier()

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Since commit f62a5d3936 ("cgroup/cpuset: Remove remote_partition_check()
& make update_cpumasks_hier() handle remote partition"), the
compute_effective_exclusive_cpumask() helper was extended to
strip exclusive CPUs from siblings when computing effective_xcpus
(cpuset.cpus.exclusive.effective). This helper was later renamed to
compute_excpus() in commit 86bbbd1f33 ("cpuset: Refactor exclusive
CPU mask computation logic").

This helper is supposed to be used consistently to compute
effective_xcpus. However, there is an exception within the callback
critical section in update_cpumasks_hier() when exclusive_cpus of a
valid partition root is empty. This can cause effective_xcpus value to
differ depending on where exactly it is last computed. Fix this by using
compute_excpus() in this case to give a consistent result.

Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

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Waiman Long 2026-01-12 11:00:18 -05:00 • committed by Tejun Heo

parent 18bc2425a8

commit a1a01793ae

1 changed files with 5 additions and 9 deletions

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kernel/cgroup/cpuset.c

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