From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261993AbUEWA16 (ORCPT ); Sat, 22 May 2004 20:27:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261998AbUEWA16 (ORCPT ); Sat, 22 May 2004 20:27:58 -0400 Received: from fw.osdl.org ([65.172.181.6]:61380 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261993AbUEWA15 (ORCPT ); Sat, 22 May 2004 20:27:57 -0400 Date: Sat, 22 May 2004 17:27:24 -0700 From: Andrew Morton To: rettw@rtwnetwork.com Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6 high CPU utilization with multimedia apps {Scanned} Message-Id: <20040522172724.6c804068.akpm@osdl.org> In-Reply-To: <32847.192.168.0.243.1085236590.squirrel@webmail.rtwsecurenet.com> References: <32847.192.168.0.243.1085236590.squirrel@webmail.rtwsecurenet.com> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org rettw@rtwnetwork.com wrote: > > I have noticed and have read several reports on the net > regarding CPU utilization differences (top displays) when > running multimedia apps on 2.6 versus late 2.4 kernels. > 2.6 running xine/mplayer/vlc etc uses 2-4 times more CPU > than 2.4.24 running the very same applications/media. > Some of the CPU appears tied up in the "X" process (I am > using the xvideo extension), the rest in the app itself. > I have seen this on every machine I have tested 2.6 on, > all with 2Ghz+ CPUs. I have tested 2.6.4, 2.6.5, 2.6.6 > vanilla kernels from kernel.org This could be an artifact from the instrumentation - if the application is doing short bursts of work the 1000Hz clock may be providing more accurate sampling. In 2.6, edit include/asm/param.h and set HZ to 100 and then redo the measurement.