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From: Jesse Barnes <jbarnes@virtuousgeek.org>
To: Pavel Machek <pavel@suse.cz>
Cc: Matthew Wilcox <matthew@wil.cx>,
	Andrew Patterson <andrew.patterson@hp.com>,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	shaohua.li@intel.com
Subject: Re: [PATCH] ASPM: Use msleep instead of cpu_relax during link retraining
Date: Mon, 5 Jan 2009 11:17:00 -0800	[thread overview]
Message-ID: <200901051117.00683.jbarnes@virtuousgeek.org> (raw)
In-Reply-To: <20081226182702.GA1528@ucw.cz>

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


  reply	other threads:[~2009-01-05 19:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-22 22:11 [PATCH] ASPM: Use msleep instead of cpu_relax during link retraining Andrew Patterson
2008-12-25 19:01 ` Pavel Machek
2008-12-25 23:24   ` Matthew Wilcox
2008-12-26 18:27     ` Pavel Machek
2009-01-05 19:17       ` Jesse Barnes [this message]
2009-01-05 19:40         ` Andrew Patterson

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