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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 26 Dec 2008 19:27:02 +0100
From:	Pavel Machek <pavel@...e.cz>
To:	Matthew Wilcox <matthew@....cx>
Cc:	Andrew Patterson <andrew.patterson@...com>,
	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 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

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/