Re: [patch] Remove the per cpu tick skew

[john stultz]

On Wed, Jul 28, 2010 at 1:26 PM, john stultz <johnstul@xxxxxxxxxx> wrote:
> On Tue, Jul 27, 2010 at 9:02 PM, Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:
>> Historically, Linux has tried to make the regular timer tick on the various
>> CPUs not happen at the same time, to avoid contention on xtime_lock.
>>
>> Nowadays, with the tickless kernel, this contention no longer happens
>> since time keeping and updating are done differently. In addition,
>> this skew is actually hurting power consumption in a measurable
>> way on many-core systems.
>>
>
> I'll give it a spin against -rt and see if we show any latency jumps.

In my testing on a 8way box, I didn't see any concerning latencies
with this patch running cyclictest or a FIFO99 gtod loop.

thanks
-john
--
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/