From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from vmail.vsnl.com (v-mail.vsnl.com [202.54.117.17]) by ozlabs.org (Postfix) with ESMTP id 61EF167A00 for ; Sat, 30 Apr 2005 01:15:34 +1000 (EST) Received: from bobys ([127.0.0.1]) by vmail.vsnl.com (iPlanet Messaging Server 5.2 HotFix 1.16 (built May 14 2003)) with SMTP id <0IFP00FITR0PEF@vmail.vsnl.com> for linuxppc-embedded@ozlabs.org; Fri, 29 Apr 2005 20:30:26 +0530 (IST) Date: Fri, 29 Apr 2005 20:31:13 +0530 From: bobys To: linuxppc-embedded@ozlabs.org Message-id: <007301c54ccc$4a013680$e63ca8c0@telxsi.com> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Subject: Performance issue - VoIP application on Linux 2.4.22 List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello everybody, I have a multithreaded VoIP application in user space and a kernel driver module on MPC 8248 based board. During media data transfer( Video Call) I have observed one strange behavior that at specific interval, cpu utilization is reaching to 100 % and then rolls back to 0 %. This behavior repeats at regular intervals of time during the call. During this time, data rate and memory utilization is constant throughout the Call. Also number of interrupts received and processed in the kernel driver is constant. We have checked the code many times, but couldn't find any of the threads/driver hogging the processor time. We are using Linux kernel 2.4.22 with kernel preemption enabled and low latency patch added. Please let me know anybody have seen same behavior and how to sort this out. Thanks and Regards Boby