Re: [PATCH] cpuidle: menu: use nr_running instead of cpuload forcalculating perf mult
From: Peter Zijlstra
Date: Mon Jun 04 2012 - 13:18:07 EST
On Mon, 2012-06-04 at 21:08 +0400, Vladimir Davydov wrote:
> But this_cpu_load(), which is currently used by cpuidle, does not
> return the "load average". It returns the value of cpuload at some
> moment in the past (actually, the value is updated in
> update_cpu_load()). This value is usually used for load balancing.
>
> Moreover, this value does not reflect the real cpu load from the
> cpuidle pow, because it depends on tasks priority (nice) and, what is
> worse, with the introduction of cgroups it can be pretty arbitrary.
> For instance, each group of tasks is accounted just as a single task
> with standard priority "spreaded" among all cpus, no matter how many
> tasks are actually running in it.
Indeed.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/