Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932336AbXAOOAl (ORCPT ); Mon, 15 Jan 2007 09:00:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932379AbXAOOAl (ORCPT ); Mon, 15 Jan 2007 09:00:41 -0500 Received: from mail.first.fraunhofer.de ([194.95.169.2]:50832 "EHLO mail.first.fraunhofer.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932353AbXAOOAk (ORCPT ); Mon, 15 Jan 2007 09:00:40 -0500 Subject: Re: prioritize PCI traffic ? From: Soeren Sonnenburg To: Vaidyanathan Srinivasan Cc: Linux Kernel In-Reply-To: <45AB8768.7000907@linux.vnet.ibm.com> References: <1168859265.15294.8.camel@localhost> <45AB8768.7000907@linux.vnet.ibm.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Mon, 15 Jan 2007 15:00:30 +0100 Message-Id: <1168869630.15294.44.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 52 On Mon, 2007-01-15 at 19:23 +0530, Vaidyanathan Srinivasan wrote: > Soeren Sonnenburg wrote: > > Dear all, > > > > is it possible to explicitly tell the kernel to prioritize PCI traffic > > for a number of cards in pci slots x,y,z ? > > > > I am asking as severe ide traffic causes lost frames when watching TV > > using 2 DVB cards + vdr... This is simply due to the fact that the PCI > > bus is saturated... > > How do you know that the bus is saturated? I simply dd if=/dev/sd? of=/dev/null from four brand new sata-harddisks. > Are you streaming data to/from the ide hard disks/CDROM? yes. > Do you have DMAs 'ON' for the hard disks? yes. > Is everything just fine if there are no IDE traffic? yes. > Are you running 2.6 kernel with preempt 'ON'? no: CONFIG_PREEMPT_NONE=y > Are all hardware on the same IRQ line? (shared interrupts) no: libata devices are on IRQ 16 and DVB devices on IRQ 20 > > So, is any prioritizing of the PCI bus possible ? > > The drivers + application indirectly can control priority on the > bus. Just reduce the priority of the application that uses IDE and > see if adjusting nice values of applications can change the scenario. That unfortunately did not help... no change... Soeren -- Sometimes, there's a moment as you're waking, when you become aware of the real world around you, but you're still dreaming. - 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/