From: Peter Zijlstra <peterz@infradead.org>
To: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: linux-kernel@vger.kernel.org,
Fernando Luis Vazquez Cao <fernando_b1@lab.ntt.co.jp>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Frederic Weisbecker <fweisbec@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Oleg Nesterov <oleg@redhat.com>,
Preeti U Murthy <preeti@linux.vnet.ibm.com>,
Denys Vlasenko <vda.linux@googlemail.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 2/2] nohz: use delayed iowait accounting to avoid race on idle time stats
Date: Thu, 17 Apr 2014 12:09:06 +0200 [thread overview]
Message-ID: <20140417100906.GP13658@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20140417100519.GF11096@twins.programming.kicks-ass.net>
On Thu, Apr 17, 2014 at 12:05:19PM +0200, Peter Zijlstra wrote:
> +static inline void iowait_start(struct rq *rq)
> +{
> + raw_spin_lock(&rq->iowait_lock);
> + rq->nr_iowait++;
> + raw_spin_unlock(&rq->iowait_lock);
> + current->in_iowait = 1;
> +}
> +
> +static inline void iowait_stop(struct rq *rq)
> +{
> + current->in_iowait = 0;
> + raw_spin_lock(&rq->iowait_lock);
> + rq->nr_iowait--;
> + if (!rq->nr_iowait && rq != this_rq())
> + rq->last_iowait = ktime_get();
> + raw_spin_unlock(&rq->iowait_lock);
> +}
We could actually use lockref here...
next prev parent reply other threads:[~2014-04-17 10:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-10 9:07 [PATCH v3 0/2] nohz: fix idle accounting in NO_HZ kernels Hidetoshi Seto
2014-04-10 9:11 ` [PATCH 1/2] nohz: stop updating sleep stats from get_cpu_{idle,iowait}_time_us() Hidetoshi Seto
2014-04-15 8:48 ` Peter Zijlstra
2014-04-15 8:49 ` Peter Zijlstra
2014-04-10 9:13 ` [PATCH 2/2] nohz: use delayed iowait accounting to avoid race on idle time stats Hidetoshi Seto
2014-04-15 10:04 ` Peter Zijlstra
2014-04-16 6:30 ` Hidetoshi Seto
2014-04-15 10:19 ` Peter Zijlstra
2014-04-16 6:33 ` Hidetoshi Seto
2014-04-16 9:36 ` Peter Zijlstra
2014-04-17 0:42 ` Hidetoshi Seto
2014-04-17 10:05 ` Peter Zijlstra
2014-04-17 10:09 ` Peter Zijlstra [this message]
2014-04-18 5:52 ` Hidetoshi Seto
2014-04-18 8:44 ` Peter Zijlstra
2014-04-15 3:11 ` [PATCH v3 0/2] nohz: fix idle accounting in NO_HZ kernels Hidetoshi Seto
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