From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932270AbWCPEU3 (ORCPT ); Wed, 15 Mar 2006 23:20:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752164AbWCPEU3 (ORCPT ); Wed, 15 Mar 2006 23:20:29 -0500 Received: from mustang.oldcity.dca.net ([216.158.38.3]:29338 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S1752156AbWCPEU2 (ORCPT ); Wed, 15 Mar 2006 23:20:28 -0500 Subject: Re: libata/sata_nv latency on NVIDIA CK804 [was Re: AMD64 X2 lost ticks on PM timer] From: Lee Revell To: "Bill Rugolsky Jr." Cc: Jeff Garzik , Ingo Molnar , Andi Kleen , Jason Baron , linux-kernel@vger.kernel.org, john stultz , Allen Martin In-Reply-To: <20060316031528.GF17817@ti64.telemetry-investments.com> References: <4408BEB5.7000407@garzik.org> <20060303234330.GA14401@ti64.telemetry-investments.com> <200603040107.27639.ak@suse.de> <20060315213638.GA17817@ti64.telemetry-investments.com> <20060315215020.GA18241@elte.hu> <20060315221119.GA21775@elte.hu> <44189654.2080607@garzik.org> <20060315224408.GC24074@elte.hu> <44189A3D.5090202@garzik.org> <20060315231426.GD17817@ti64.telemetry-investments.com> <20060316031528.GF17817@ti64.telemetry-investments.com> Content-Type: text/plain Date: Wed, 15 Mar 2006 23:20:24 -0500 Message-Id: <1142482825.1671.148.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.6.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-03-15 at 22:15 -0500, Bill Rugolsky Jr. wrote: > > I'm heading home now (it's 22:00, and I've been here 16 hours > already), but I figured that I'd post what I have thus far, and > perhaps you can tell me what the problem is. > I think it would be better to try to identify the exact circumstances that trigger the large PIO delay, than to start over debugging a new and untested driver, especially if the SMM hypothesis has been ruled out. You mentioned before the bug only hits with writes to multiple drives - can you try to identify a pattern here - stress the drives one at a time, try RAID vs. stressing both drives independently, remove one from the bus. See if anything affects the duration of the latencies, etc. Lots of people have these boards and it seems like if the problem was widespread, I would have seen it on the Linux audio lists, as many of those users run Ingo's instrumented kernel and they all know to report latency traces when they get them. Lee