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

From: Pavel Machek
Date: Fri Dec 26 2008 - 13:27:22 EST


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.

Thanks.
Pavel

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