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: Hao Sun <sunhao.th@xxxxxxxxx> Link: https://lore.kernel.org/r/CACkBjsbPVdkub=e-E-p1WBOLxS515ith-53SFdmFHWV_QMo40w@xxxxxxxxxxxxxx Suggested-by: Hao Sun <sunhao.th@xxxxxxxxx> Signed-off-by: Michal Koutný <mkoutny@xxxxxxxx> --- kernel/cgroup/rstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Hao was silent in the reporting mail thread, so I'm sending the suggested annotating patch. diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index 1486768f2318..1abe74114527 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -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); -- 2.33.1
