Re: [PATCH] sched: Fix the irqtime code to deal with u64 wraps

From: Nicolas Pitre
Date: Fri Dec 10 2010 - 21:23:19 EST


On Fri, 10 Dec 2010, Peter Zijlstra wrote:

> OK, so here's the latest version, using fancy __this_cpu thingies.
>
> I started a new thread since the old one was quite unwieldy.
>
> Now, admittedly this patch is a tad large, esp for -rc5. So either we
> need lots of Reviewed-by and such or I need to shrink this patch
> somehow.
>
>
> ---
> Subject: sched: Fix the irqtime code to deal with u64 wraps
> From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Date: Thu Dec 09 14:15:34 CET 2010
>
> ARM systems have a 32bit sched_clock() [ which needs to be fixed ],
> but this exposed a bug in the irq_time code as well, it doesn't deal
> with wraps at all.
[...]

That would be more close to reality if you stated "Some ARM systems have
a 32bit sched_clock() [" above. Most ARM systems in use today have a
sched_clock() with more than 32 bits, like 55 bits or so.


Nicolas
--
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/