Re: [patch] sched: accurate user accounting

[malc]

On Sun, 25 Mar 2007, Con Kolivas wrote:

> On Sunday 25 March 2007 21:46, Con Kolivas wrote:
> > On Sunday 25 March 2007 21:34, malc wrote:
> > > On Sun, 25 Mar 2007, Ingo Molnar wrote:
> > > > * Con Kolivas <kernel@xxxxxxxxxxx> wrote:
> > > > > For an rsdl 0.33 patched kernel. Comments? Overhead worth it?

[..snip..]

> ---
> Currently we only do cpu accounting to userspace based on what is
> actually happening precisely on each tick. The accuracy of that
> accounting gets progressively worse the lower HZ is. As we already keep
> accounting of nanosecond resolution we can accurately track user cpu,
> nice cpu and idle cpu if we move the accounting to update_cpu_clock with
> a nanosecond cpu_usage_stat entry. This increases overhead slightly but
> avoids the problem of tick aliasing errors making accounting unreliable.
>
> Signed-off-by: Con Kolivas <kernel@xxxxxxxxxxx>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

[..snip..]

Forgot to mention. Given that this goes into the kernel, shouldn't
Documentation/cpu-load.txt be amended/removed?

--
vale
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