Sender: Tejun Heo <htejun@gmail.com>
Date:   Wed, 12 Jan 2022 10:42:22 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Cruz Zhao <CruzZhao@linux.alibaba.com>
Cc:     lizefan.x@bytedance.com, hannes@cmpxchg.org, mingo@redhat.com,
        peterz@infradead.org, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        bristot@redhat.com, joshdon@google.com, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/3] sched/core: Force idle accounting per cgroup
Message-ID: <Yd89Lv3VuaaFVm4h@slm.duckdns.org>
References: <1641894961-9241-1-git-send-email-CruzZhao@linux.alibaba.com>
 <1641894961-9241-4-git-send-email-CruzZhao@linux.alibaba.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1641894961-9241-4-git-send-email-CruzZhao@linux.alibaba.com>
Precedence: bulk

Hello,

On Tue, Jan 11, 2022 at 05:56:01PM +0800, Cruz Zhao wrote:
> +#ifdef CONFIG_SCHED_CORE
> +void cpuacct_account_forceidle(int cpu, struct task_struct *tsk, u64 cputime)
> +{
> +	struct cpuacct *ca;
> +	u64 *fi;
> +
> +	rcu_read_lock();
> +	/*
> +	 * We have hold rq->core->__lock here, which protects ca->forceidle
> +	 * percpu.
> +	 */
> +	for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) {
> +		fi = per_cpu_ptr(ca->forceidle, cpu);
> +		*fi += cputime;
> +	}

Please don't do this. Use rstat and integrate it with other stats.

Thanks.

-- 
tejun