Commit eda09706 authored by Michal Koutný's avatar Michal Koutný Committed by Tejun Heo
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cgroup: rstat: Mark benign data race to silence KCSAN 



There is a race between updaters and flushers (flush can possibly miss
the latest update(s)). This is expected as explained in
cgroup_rstat_updated() comment, add also machine readable annotation so
that KCSAN results aren't noisy.

Reported-by: default avatarHao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/r/CACkBjsbPVdkub=e-E-p1WBOLxS515ith-53SFdmFHWV_QMo40w@mail.gmail.com


Suggested-by: default avatarHao Sun <sunhao.th@gmail.com>

Signed-off-by: default avatarMichal Koutný <mkoutny@suse.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 8ab77458

kernel/cgroup/rstat.c

+1 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) 
	 * instead of NULL, we can tell whether @cgrp is on the list by

	 * testing the next pointer for NULL.

	 */

	if (cgroup_rstat_cpu(cgrp, cpu)->updated_next)

	if (data_race(cgroup_rstat_cpu(cgrp, cpu)->updated_next))

		return;



	raw_spin_lock_irqsave(cpu_lock, flags);