Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751735AbXA0Acm (ORCPT ); Fri, 26 Jan 2007 19:32:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751823AbXA0Acm (ORCPT ); Fri, 26 Jan 2007 19:32:42 -0500 Received: from wx-out-0506.google.com ([66.249.82.234]:60232 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751735AbXA0Acl (ORCPT ); Fri, 26 Jan 2007 19:32:41 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=b6q/rCfNe3aFeGyPmfhFlrAzbmqDR4aGeWKg1wwDKkvJEsL6q8ImqRzkGTADU+fF04beeYDtRbx38dFG/UWYqz9on/4HidndEG2mYdFLPd+e9IGLnxdDWFGIOWyKPJHTRMhwafN7mUAOFvi8g5LANC2JcfxNHQoYzc17G6Rh/Z8= Message-ID: <75b66ecd0701261632q1a93b487u81539d850df10db0@mail.gmail.com> Date: Fri, 26 Jan 2007 19:32:40 -0500 From: "Lee Revell" To: "Hans-Peter Jansen" Subject: Re: prioritize PCI traffic ? Cc: linux-kernel@vger.kernel.org, "Vaidyanathan Srinivasan" , "Soeren Sonnenburg" In-Reply-To: <200701172122.27407.hpj@urpla.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1168859265.15294.8.camel@localhost> <1168869630.15294.44.camel@localhost> <45AB956A.5070103@linux.vnet.ibm.com> <200701172122.27407.hpj@urpla.net> X-Google-Sender-Auth: a13e7f12ebbc77c4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 906 Lines: 22 On 1/17/07, Hans-Peter Jansen wrote: > Am Montag, 15. Januar 2007 15:53 schrieb Vaidyanathan Srinivasan: > > > > 33Mhz 32-bit PCI bus on typical PC can do around 100MB/sec... > > Substract roughly n * 5MB for VIA chipsets, where n is the age (1 <= n <= > 4), and even more for SIS, ATI.. While developing the latency tracer in the -rt kernel, Ingo and others discovered that some SATA controllers can produce very bad DMA starvation at higher speeds. A latency trace of such an event looks like the entire system is going in slow motion. Presumably, vendors do this to improve benchmark scores. Try forcing your drives to a lower speed. Lee - 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/