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authorChengming Zhou <zhouchengming@bytedance.com>2022-02-20 13:14:24 +0800
committerPeter Zijlstra <peterz@infradead.org>2022-03-01 16:18:37 +0100
commit248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd (patch)
treee97bb003738542a43b72421b2f88737f26a62b92 /kernel/sched/cpuacct.c
parentMerge tag 'v5.17-rc5' into sched/core, to resolve conflicts (diff)
downloadlinux-dev-248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd.tar.xz
linux-dev-248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd.zip
sched/cpuacct: Fix charge percpu cpuusage
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
Diffstat (limited to '')
-rw-r--r--kernel/sched/cpuacct.c3
1 files changed, 2 insertions, 1 deletions
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();
}