From: Chengming Zhou <zhouchengming@bytedance.com>
To: mingo@redhat.com, peterz@infradead.org,
vincent.guittot@linaro.org, bristot@redhat.com,
zhaolei@cn.fujitsu.com, tj@kernel.org, lizefan.x@bytedance.com,
hannes@cmpxchg.org
Cc: linux-kernel@vger.kernel.org,
Chengming Zhou <zhouchengming@bytedance.com>,
Minye Zhu <zhuminye@bytedance.com>
Subject: [PATCH v3 1/3] sched/cpuacct: fix charge percpu cpuusage
Date: Sun, 20 Feb 2022 13:14:24 +0800 [thread overview]
Message-ID: <20220220051426.5274-1-zhouchengming@bytedance.com> (raw)
The cpuacct_account_field() is always called by the current task
itself, so it's ok to use __this_cpu_add() to charge the tick time.
But cpuacct_charge() maybe called by update_curr() in load_balance()
on a random CPU, different from the CPU on which the task is running.
So __this_cpu_add() will charge that cputime to a random incorrect CPU.
Fixes: 73e6aafd9ea8 ("sched/cpuacct: Simplify the cpuacct code")
Reported-by: Minye Zhu <zhuminye@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
kernel/sched/cpuacct.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 3d06c5e4220d..307800586ac8 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -334,12 +334,13 @@ static struct cftype files[] = {
*/
void cpuacct_charge(struct task_struct *tsk, u64 cputime)
{
+ unsigned int cpu = task_cpu(tsk);
struct cpuacct *ca;
rcu_read_lock();
for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
- __this_cpu_add(*ca->cpuusage, cputime);
+ *per_cpu_ptr(ca->cpuusage, cpu) += cputime;
rcu_read_unlock();
}
--
2.20.1
next reply other threads:[~2022-02-20 5:15 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-20 5:14 Chengming Zhou [this message]
2022-02-20 5:14 ` [PATCH v3 2/3] sched/cpuacct: optimize away RCU read lock Chengming Zhou
2022-03-01 15:24 ` [tip: sched/core] sched/cpuacct: Optimize " tip-bot2 for Chengming Zhou
[not found] ` <CGME20220308232034eucas1p2b0f39cee0f462af6004ebdfbe5bacb9f@eucas1p2.samsung.com>
2022-03-08 23:20 ` [PATCH v3 2/3] sched/cpuacct: optimize " Marek Szyprowski
2022-03-08 23:32 ` Peter Zijlstra
2022-03-08 23:44 ` Paul E. McKenney
2022-03-09 0:21 ` Paul E. McKenney
2022-03-10 8:45 ` Peter Zijlstra
2022-03-10 15:01 ` Paul E. McKenney
2022-03-12 12:15 ` Peter Zijlstra
2022-03-12 17:44 ` Paul E. McKenney
2022-03-09 3:08 ` [External] " Chengming Zhou
2022-02-20 5:14 ` [PATCH v3 3/3] sched/cpuacct: remove redundant " Chengming Zhou
2022-03-01 15:24 ` [tip: sched/core] sched/cpuacct: Remove " tip-bot2 for Chengming Zhou
[not found] ` <CGME20220308233107eucas1p119a2f5a8d4f5b5eec38ea8dde92b3368@eucas1p1.samsung.com>
2022-03-08 23:31 ` [PATCH v3 3/3] sched/cpuacct: remove " Marek Szyprowski
2022-02-22 18:01 ` [PATCH v3 1/3] sched/cpuacct: fix charge percpu cpuusage Tejun Heo
2022-02-23 9:11 ` Peter Zijlstra
2022-03-01 15:24 ` [tip: sched/core] sched/cpuacct: Fix " tip-bot2 for Chengming Zhou
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