Re: [PATCH] sched/cpuacct: fix charge percpu cpuusage

[Tejun Heo]

On Mon, Feb 14, 2022 at 11:09:01AM +0100, Peter Zijlstra wrote:
> --- a/kernel/sched/cpuacct.c
> +++ b/kernel/sched/cpuacct.c
> @@ -334,15 +334,13 @@ static struct cftype files[] = {
>   */
>  void cpuacct_charge(struct task_struct *tsk, u64 cputime)
>  {
> -	struct cpuacct *ca;
>  	unsigned int cpu = task_cpu(tsk);
> +	struct cpuacct *ca;
>  
> -	rcu_read_lock();
> +	lockdep_assert_rq_held(cpu_rq(cpu));
>  
>  	for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
>  		*per_cpu_ptr(ca->cpuusage, cpu) += cputime;
> -
> -	rcu_read_unlock();

And probably expand the same to cgroup_account_cputime[_field]() too.

Thanks.

-- 
tejun