From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751758Ab1HPPQa (ORCPT ); Tue, 16 Aug 2011 11:16:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59807 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136Ab1HPPQ2 (ORCPT ); Tue, 16 Aug 2011 11:16:28 -0400 Date: Tue, 16 Aug 2011 11:16:05 -0400 From: Don Zickus To: Alex Neronskiy Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, Ingo Molnar , Mandeep Singh Baines Subject: Re: [PATCH v7 2/2] Output stall data in debugfs Message-ID: <20110816151605.GL1972@redhat.com> References: <1313105708-13331-1-git-send-email-zakmagnus@chromium.org> <1313105708-13331-2-git-send-email-zakmagnus@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1313105708-13331-2-git-send-email-zakmagnus@chromium.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 11, 2011 at 04:35:08PM -0700, Alex Neronskiy wrote: > Instead of using the log, use debugfs for output of both stall > lengths and stack traces. Printing to the log can result in > watchdog touches, distorting the very events being measured. > Additionally, the information will not distract from lockups > when users view the log. > > A two-buffer system is used to ensure that the trace information > can always be recorded without contention. > > Signed-off-by: Alex Neronskiy > --- > Changes from last version per Peter's suggestions: different > locks, refactoring, ACCESS_ONCE. I think I am going to ignore these patches for now until I see if you can solve things using Ingo's idea. Cheers, Don