7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guopeng Zhang [ Upstream commit 2bf404b1bd94f50747443234c0a4a5e18e2569bf ] check_isolcpus() clears ISOLCPUS before rebuilding it from sched domain data. Comparing that empty value with /sys/devices/system/cpu/isolated makes the test fail whenever isolcpus=domain is present. That sysfs file is generated from HK_TYPE_DOMAIN_BOOT and does not change when cpuset updates HK_TYPE_DOMAIN. Re-reading it cannot validate dynamic housekeeping updates. The cpuset.cpus.isolated and sched domain checks already cover the two dynamic interfaces, so remove the invalid comparison. This can be reproduced on a kernel booted with isolcpus=domain,15: # tools/testing/selftests/cgroup/test_cpuset_prs.sh The test fails its first state-matrix isolation check before the change and continues past that check afterward. Fixes: 6df415aa46ec ("cgroup/cpuset: Defer housekeeping_update() calls from CPU hotplug to workqueue") Signed-off-by: Guopeng Zhang Reviewed-by: Waiman Long Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- tools/testing/selftests/cgroup/test_cpuset_prs.sh | 6 ------ 1 file changed, 6 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh index b2e60671273ec..ebbc5b4def243 100755 --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh @@ -791,7 +791,6 @@ check_isolcpus() EXPECTED_ISOLCPUS=$1 ISCPUS=${CGROUP2}/cpuset.cpus.isolated ISOLCPUS=$(cat $ISCPUS) - HKICPUS=$(cat /sys/devices/system/cpu/isolated) LASTISOLCPU= SCHED_DOMAINS=/sys/kernel/debug/sched/domains if [[ $EXPECTED_ISOLCPUS = . ]] @@ -829,11 +828,6 @@ check_isolcpus() ISOLCPUS= EXPECTED_ISOLCPUS=$EXPECTED_SDOMAIN - # - # The inverse of HK_TYPE_DOMAIN cpumask in $HKICPUS should match $ISOLCPUS - # - [[ "$ISOLCPUS" != "$HKICPUS" ]] && return 1 - # # Use the sched domain in debugfs to check isolated CPUs, if available # -- 2.53.0