cgroup: Fix rootcg cpu.stat guest double counting

[ Upstream commit 81c49d39ae ]

In account_guest_time in kernel/sched/cputime.c guest time is
attributed to both CPUTIME_NICE and CPUTIME_USER in addition to
CPUTIME_GUEST_NICE and CPUTIME_GUEST respectively. Therefore, adding
both to calculate usage results in double counting any guest time at
the rootcg.

Fixes: 936f2a70f2 ("cgroup: add cpu.stat file to root cgroup")
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dan Schatzberg 2021-10-28 15:15:27 -07:00 committed by Greg Kroah-Hartman
parent c47be68b31
commit e3acd3a084

View File

@ -433,8 +433,6 @@ static void root_cgroup_cputime(struct task_cputime *cputime)
cputime->sum_exec_runtime += user;
cputime->sum_exec_runtime += sys;
cputime->sum_exec_runtime += cpustat[CPUTIME_STEAL];
cputime->sum_exec_runtime += cpustat[CPUTIME_GUEST];
cputime->sum_exec_runtime += cpustat[CPUTIME_GUEST_NICE];
}
}