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| author | Chengming Zhou <zhouchengming@bytedance.com> | 2022-02-20 08:14:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:23:11 +0300 |
| commit | b7aec0843e2883b4bd5bed46f70b0febb046f9cc (patch) | |
| tree | 858668f8ae84d669ee10f769267645c3aca4962f /kernel/sched | |
| parent | cc91880f041705062aab4cc1d4e1271f4ecabd08 (diff) | |
| download | linux-b7aec0843e2883b4bd5bed46f70b0febb046f9cc.tar.xz | |
sched/cpuacct: Fix charge percpu cpuusage
[ Upstream commit 248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd ]
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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220220051426.5274-1-zhouchengming@bytedance.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/cpuacct.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index ab67d97a8442..cacc2076ad21 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -328,12 +328,13 @@ 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(); } |