Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262306AbTEIGlG (ORCPT ); Fri, 9 May 2003 02:41:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262310AbTEIGlF (ORCPT ); Fri, 9 May 2003 02:41:05 -0400 Received: from zcars04e.nortelnetworks.com ([47.129.242.56]:57297 "EHLO zcars04e.nortelnetworks.com") by vger.kernel.org with ESMTP id S262306AbTEIGlD (ORCPT ); Fri, 9 May 2003 02:41:03 -0400 Message-ID: <3EBB504C.1030001@nortelnetworks.com> Date: Fri, 09 May 2003 02:53:00 -0400 X-Sybari-Space: 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.8) Gecko/20020204 X-Accept-Language: en-us MIME-Version: 1.0 To: William Lee Irwin III Cc: Linux Kernel Mailing List Subject: Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues References: <3EBAD63C.4070808@nortelnetworks.com> <20030509001339.GQ8978@holomorphy.com> <20030509003825.GR8978@holomorphy.com> <3EBB25FD.7060809@nortelnetworks.com> <20030509042659.GS8978@holomorphy.com> <3EBB4735.30701@nortelnetworks.com> <20030509062008.GT8978@holomorphy.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 943 Lines: 27 William Lee Irwin III wrote: > I don't understand why you're obsessed with interrupts. Just run your > load and spray the scheduler latency stats out /proc/ I'm obsessed with interrupts because it gives me a higher sampling rate. I could set up and itimer for a recurring 10ms timeout and see how much extra I waited, but then I can only get 100 samples/sec. With /dev/rtc (on intel) you can get 20x more samples in the same amount of time. Chris -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com - 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/