From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753677AbXABTo0 (ORCPT ); Tue, 2 Jan 2007 14:44:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754923AbXABToZ (ORCPT ); Tue, 2 Jan 2007 14:44:25 -0500 Received: from wx-out-0506.google.com ([66.249.82.225]:15586 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753677AbXABToZ (ORCPT ); Tue, 2 Jan 2007 14:44:25 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=l0jOVXKZHQzToTSGmNS3E7+GfEJiaQHxZKoB5gMwQPQSohxMV81arJ7s8MZFse8nQeB4vO1QspUbcV+LF1A3jnR81qJTIFqVNeVRblBhNkd/x7CgyS+by88bbMyOyLaOL3oEGJvfhVr/bAYeWUNIxwLnU8YRxvS4Vzsni0wyhe0= Message-ID: <20f65d530701021144p2df613dbvd5fe654ffcd09f91@mail.gmail.com> Date: Wed, 3 Jan 2007 08:44:24 +1300 From: "Keith Chew" To: linux-kernel@vger.kernel.org Subject: Performance bttv versus sharedmem MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi This is just a general question to understand where the improvement can be made. In the first setup, I have these processes: - mencoder recording from bttv chip at 8 fps (cpu 3.5 %) - mplayer playing from bttv chip at 10 fps (cpu 2.1 %) In the second setup, I have these processes: - mencoder recording from bttv to shared mem at 25 fps (cpu 1.7%) - mencoder recording from shared mem at 8 fps (cpu 6.1%) - mplayer playing from shared mem at 10 fps (cpu 3.1 %) For the shared mem setup, the access to the memory is efficient, only a memcopy to a buffer. Are the CPU usages inline with what you'd expect, that the shared mem being almost 2 times the CPU usage? How can I reduce the CPU usage in the shared mem setup? Regards Keith