Date: Sun, 18 Aug 2013 19:00:01 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Fernando Luis Vazquez Cao <fernando_b1@lab.ntt.co.jp>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: [PATCH 3/4] nohz: Consolidate sleep time stats read code
Message-ID: <20130818170001.GC21310@redhat.com>
References: <1376667753-29014-1-git-send-email-fweisbec@gmail.com> <1376667753-29014-4-git-send-email-fweisbec@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1376667753-29014-4-git-send-email-fweisbec@gmail.com>
User-Agent: Mutt/1.5.18 (2008-05-17)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1216
Lines: 42

On 08/16, Frederic Weisbecker wrote:
>
> get_cpu_idle_time_us() and get_cpu_iowait_time_us() mostly share
> the same code. Lets consolidate both implementations.

Personally I like every patch which consolidates the code ;)

>  	do {
>  		seq = read_seqcount_begin(&ts->sleeptime_seq);
> -		if (ts->idle_active && !nr_iowait_cpu(cpu)) {
> +		if (io)
> +			sleep = ts->iowait_sleeptime;
> +		else
> +			sleep = ts->idle_sleeptime;
> +
> +		if (ts->idle_active)
> +			continue;
> +
> +		if ((io && nr_iowait_cpu(cpu)) || (!io && !nr_iowait_cpu(cpu))) {
>  			ktime_t delta = ktime_sub(now, ts->idle_entrytime);
> -			idle = ktime_add(ts->idle_sleeptime, delta);
> -		} else {
> -			idle = ts->idle_sleeptime;
> +			sleep = ktime_add(sleep, delta);
>  		}
>  	} while (read_seqcount_retry(&ts->sleeptime_seq, seq));

Cosmetic/subjective, feel free to ignore. but perhaps

		if (ts->idle_active && io == !!nr_iowait_cpu(cpu)) {
			...
		}

looks more understandable.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/