Re: [PATCH 3/4] nohz: Consolidate sleep time stats read code

From: Oleg Nesterov
Date: Sun Aug 18 2013 - 13:06:21 EST


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.

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