linux-kernel - Re: [PATCH] ASPM: Use msleep instead of cpu

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Message-Id: <1231184412.18550.24.camel@bluto>
Date:	Mon, 05 Jan 2009 12:40:12 -0700
From:	Andrew Patterson <andrew.patterson@...com>
To:	Jesse Barnes <jbarnes@...tuousgeek.org>
Cc:	Pavel Machek <pavel@...e.cz>, Matthew Wilcox <matthew@....cx>,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	shaohua.li@...el.com
Subject: Re: [PATCH] ASPM: Use msleep instead of cpu_relax during link
 retraining

On Mon, 2009-01-05 at 11:17 -0800, Jesse Barnes wrote:
> 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?
> 

Will do.

Andrew

> Thanks,

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