Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 7 Feb 2003 21:07:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 7 Feb 2003 21:07:11 -0500 Received: from e1.ny.us.ibm.com ([32.97.182.101]:11442 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id ; Fri, 7 Feb 2003 21:07:10 -0500 Subject: Re: [RFC][PATCH] linux-2.5.59_getcycles_A0 From: john stultz To: Andi Kleen Cc: lkml , Joel Becker In-Reply-To: <20030208015235.GA25432@wotan.suse.de> References: <1044649542.18673.20.camel@w-jstultz2.beaverton.ibm.com.suse.lists.linux.kernel> <1044659375.18676.80.camel@w-jstultz2.beaverton.ibm.com> <20030208001844.GA20849@wotan.suse.de> <1044665441.18670.106.camel@w-jstultz2.beaverton.ibm.com> <20030208015235.GA25432@wotan.suse.de> Content-Type: text/plain Organization: Message-Id: <1044670483.21642.18.camel@w-jstultz2.beaverton.ibm.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 Date: 07 Feb 2003 18:14:43 -0800 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 844 Lines: 24 On Fri, 2003-02-07 at 17:52, Andi Kleen wrote: > > However this doesn't work on systems w/o a synced TSC, so by simply > > Why not? This shouldn't be performance critical and you can make > it monotonous with an additional variable + lock if backwards jumps > should be a problem. > That sounds horrible! The extra locking and variable reading is going to kill most of the performance concerns you have about reading an alternate time source. I'm not sure I understand your resistance to using an alternate clock for get_cycles(). Could you better explain your problem with it? thanks -john - 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/