kselftest/cgroup: Add cleanup() to test_cpuset_prs.sh

Install a cleanup function using the trap command for signals EXIT,
SIGINT, SIGQUIT and SIGABRT.  The cleanup function will perform:
1. Online the CPUs that were made offline during the test.
2. Removing the cgroups created.
3. Restoring the original /sys/kernel/debug/sched/verbose value,
   currently it's left turned on, irrespective of the original
   configuration value.

the test performs steps 1 and 2, on the successful runs, but not during
all of the failed runs.  With the cleanup(), the system will perform all
three steps during failed/passed test runs.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: kamalesh-babulal

tools/testing/selftests/cgroup/test_cpuset_prs.sh

@@ -16,7 +16,12 @@ skip_test() {
 [[ $(id -u) -eq 0 ]] || skip_test "Test must be run as root!"
 
 # Set sched verbose flag, if available
-[[ -d /sys/kernel/debug/sched ]] && echo Y > /sys/kernel/debug/sched/verbose
+if [[ -d /sys/kernel/debug/sched ]]
+then
+	# Used to restore the original setting during cleanup
+	SCHED_DEBUG=$(cat /sys/kernel/debug/sched/verbose)
+	echo Y > /sys/kernel/debug/sched/verbose
+fi
 
 # Get wait_inotify location
 WAIT_INOTIFY=$(cd $(dirname $0); pwd)/wait_inotify
@@ -54,6 +59,15 @@ echo +cpuset > cgroup.subtree_control
 [[ -d test ]] || mkdir test
 cd test
 
+cleanup()
+{
+	online_cpus
+	rmdir A1/A2/A3 A1/A2 A1 B1 > /dev/null 2>&1
+	cd ..
+	rmdir test > /dev/null 2>&1
+	echo "$SCHED_DEBUG" > /sys/kernel/debug/sched/verbose
+}
+
 # Pause in ms
 pause()
 {
@@ -666,6 +680,7 @@ test_inotify()
 	fi
 }
 
+trap cleanup 0 2 3 6
 run_state_test TEST_MATRIX
 test_isolated
 test_inotify