Re: [PATCH] ASPM: Use msleep instead of cpu_relax during link retraining

From: Jesse Barnes
Date: Mon Jan 05 2009 - 14:17:19 EST


On Friday, December 26, 2008 10:27 am Pavel Machek wrote:
> On Thu 2008-12-25 16:24:27, Matthew Wilcox wrote:
> > On Thu, Dec 25, 2008 at 08:01:29PM +0100, Pavel Machek wrote:
> > > On Mon 2008-12-22 15:11:57, Andrew Patterson wrote:
> > > > ASPM: Use msleep instead of cpu_relax during link retraining
> > > >
> > > > The cpu_relax() function can be a noop on certain architectures
> > > > like IA-64 when CPU threads are disabled, so use msleep instead
> > > > during link retraining busy/wait loop.
> > >
> > > Author clearly wanted to do a busy loop... why do you think 10msec
> > > delay here is acceptable?
> >
> > 10ms? I see a 1ms sleep.
>
> Yes... IIRC msleep will sleep for up-to 1/HZ on non-highres systems.
>
> > Yes, the subsequent test should be of reg16 instead of jiffies.

Andrew, care to send an updated patch which includes fixes for the issues
caught by Pavel & Matthew?

Thanks,
--
Jesse Barnes, Intel Open Source Technology Center

--
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/