Re: [patch] sched: accurate user accounting

From: Con Kolivas
Date: Sun Mar 25 2007 - 04:40:58 EST


On Sunday 25 March 2007 17:51, Ingo Molnar wrote:
> * Con Kolivas <kernel@xxxxxxxxxxx> wrote:
> > For an rsdl 0.33 patched kernel. Comments? Overhead worth it?
>
> we want to do this - and we should do this to the vanilla scheduler
> first and check the results. I've back-merged the patch to before RSDL
> and have tested it - find the patch below. Vale, could you try this
> patch against a 2.6.21-rc4-ish kernel and re-test your testcase?

Great. That should fix a lot of misconceptions about cpu usage and HZ.

However-

> +/*
> + * Some helpers for converting nanosecond timing to jiffy resolution
> + */
> +#define NS_TO_JIFFIES(TIME) ((TIME) / (1000000000 / HZ))
> +#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
> +

This hunk is already in mainline so it will be double defined now.

Thanks.

--
-ck
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