Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964890AbVITFLL (ORCPT ); Tue, 20 Sep 2005 01:11:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932728AbVITFLL (ORCPT ); Tue, 20 Sep 2005 01:11:11 -0400 Received: from 213-239-205-147.clients.your-server.de ([213.239.205.147]:32728 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S932727AbVITFLJ (ORCPT ); Tue, 20 Sep 2005 01:11:09 -0400 Subject: Re: [ANNOUNCE] ktimers subsystem From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Christopher Friesen Cc: Christoph Lameter , linux-kernel@vger.kernel.org, mingo@elte.hu, akpm@osdl.org, george@mvista.com, johnstul@us.ibm.com, paulmck@us.ibm.com In-Reply-To: <432F96C1.70303@nortel.com> References: <20050919184834.1.patchmail@tglx.tec.linutronix.de> <1127168232.24044.265.camel@tglx.tec.linutronix.de> <432F3E0F.1010002@nortel.com> <1127170488.24044.291.camel@tglx.tec.linutronix.de> <432F96C1.70303@nortel.com> Content-Type: text/plain Organization: linutronix Date: Tue, 20 Sep 2005 07:11:17 +0200 Message-Id: <1127193078.24044.303.camel@tglx.tec.linutronix.de> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1230 Lines: 32 On Mon, 2005-09-19 at 22:57 -0600, Christopher Friesen wrote: > >>--flight-recorder style logs > > > If you want to implement such stuff efficiently you rely on rdtscll() on > > x86 or other monotonic easy accessible time souces and not on a > > permanent call to gettimeofday. > > Not portable across architectures, and doesn't work across all smp/numa > environments. Also not easy to compare with other nodes on the network, > whereas with ntp-synch'd nodes you can use gettimeofday() for quite > accurate correlations. Sorry was a stupid argument. Withdrawn herby > > Please beware me of red herrings. If application developers code with > > respect to random OS worst case behaviour then they should not complain > > that OS N is having an additional add instruction in one of the pathes. > > Actually I'm not complaining about additional add instructions. I was > just suggesting some reasons why apps might reasonably want to know the > time frequently. ok tglx - 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/