Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753890AbZAEThg (ORCPT ); Mon, 5 Jan 2009 14:37:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752247AbZAETh1 (ORCPT ); Mon, 5 Jan 2009 14:37:27 -0500 Received: from g1t0026.austin.hp.com ([15.216.28.33]:26242 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbZAETh0 (ORCPT ); Mon, 5 Jan 2009 14:37:26 -0500 Subject: Re: [PATCH] ASPM: Use msleep instead of cpu_relax during link retraining From: Andrew Patterson To: Jesse Barnes Cc: Pavel Machek , Matthew Wilcox , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, shaohua.li@intel.com In-Reply-To: <200901051117.00683.jbarnes@virtuousgeek.org> References: <20081222221156.29645.95982.stgit@bluto> <20081225232427.GJ19967@parisc-linux.org> <20081226182702.GA1528@ucw.cz> <200901051117.00683.jbarnes@virtuousgeek.org> Content-Type: text/plain Date: Mon, 05 Jan 2009 12:40:12 -0700 Message-Id: <1231184412.18550.24.camel@bluto> Mime-Version: 1.0 X-Mailer: Evolution 2.24.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1268 Lines: 35 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, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/