From: Waiman Long <longman@redhat.com> mainline inclusion from mainline-v6.13-rc7 commit 9b496a8bbed9cc292b0dfd796f38ec58b6d0375f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBJ6GQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- Isolated CPUs are not allowed to be used in a non-isolated partition. The only exception is the top cpuset which is allowed to contain boot time isolated CPUs. Commit ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem") introduces a simplified scheme of including only partition roots in sched domain generation. However, it does not properly account for this exception case. This can result in leakage of isolated CPUs into a sched domain. Fix it by making sure that isolated CPUs are excluded from the top cpuset before generating sched domains. Also update the way the boot time isolated CPUs are handled in test_cpuset_prs.sh to make sure that those isolated CPUs are really isolated instead of just skipping them in the tests. Fixes: ccac8e8de99c ("cgroup/cpuset: Fix remote root partition creation problem") Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Conflicts: tools/testing/selftests/cgroup/test_cpuset_prs.sh [selftests conflicts, did not apply for hulk] Signed-off-by: Chen Ridong <chenridong@huawei.com> --- kernel/cgroup/cpuset.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 53ba804a81603..26d3a17e8806d 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1247,7 +1247,15 @@ static int generate_sched_domains(cpumask_var_t **domains, */ if (cgrpv2) { for (i = 0; i < ndoms; i++) { - cpumask_copy(doms[i], csa[i]->effective_cpus); + /* + * The top cpuset may contain some boot time isolated + * CPUs that need to be excluded from the sched domain. + */ + if (csa[i] == &top_cpuset) + cpumask_and(doms[i], csa[i]->effective_cpus, + housekeeping_cpumask(HK_TYPE_DOMAIN)); + else + cpumask_copy(doms[i], csa[i]->effective_cpus); if (dattr) dattr[i] = SD_ATTR_INIT; } -- 2.34.1