From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261726AbULNWxI (ORCPT ); Tue, 14 Dec 2004 17:53:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261692AbULNWuy (ORCPT ); Tue, 14 Dec 2004 17:50:54 -0500 Received: from mustang.oldcity.dca.net ([216.158.38.3]:36029 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S261709AbULNWuV (ORCPT ); Tue, 14 Dec 2004 17:50:21 -0500 Subject: Re: dynamic-hz From: Lee Revell To: Con Kolivas Cc: Andrea Arcangeli , Pavel Machek , linux-kernel@vger.kernel.org In-Reply-To: References: <20041211142317.GF16322@dualathlon.random> <20041212163547.GB6286@elf.ucw.cz> <20041212222312.GN16322@dualathlon.random> <41BCD5F3.80401@kolivas.org> <1103063312.14699.54.camel@krustophenia.net> Content-Type: text/plain Date: Tue, 14 Dec 2004 17:50:19 -0500 Message-Id: <1103064619.14699.73.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2004-12-15 at 09:40 +1100, Con Kolivas wrote: > Lee Revell writes: > > > On Mon, 2004-12-13 at 10:36 +1100, Con Kolivas wrote: > >> The performance benefit, if any, is often lost in noise during > >> benchmarks and when there, is less than 1%. > > > > I have measured 2.1-2.3% residency for the timer ISR on my 600Mhz VIA > > C3. And this is a desktop - you have many many embedded systems that > > are slower. For these systems the difference is very real. > > Could you explain residency and it's relevance to throughput please? I've > not heard this term before. > It means 2.1-2.3% of wallclock time is spent running the timer interrupt handler. IOW, it runs for 21-23 usecs, 1000x per second. Lee