From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: Re: [Q] workaround for ide (native) leads to irq storm? Date: Fri, 17 Nov 2006 15:54:43 +0300 Message-ID: <455DB113.4000309@sw.ru> References: <453DC2A9.8000507@sw.ru> <453DC65C.8000408@sw.ru> <454206EE.9080206@sw.ru> <1161958862.16839.26.camel@localhost.localdomain> <4559879D.8090105@sw.ru> <455AF01C.5090307@gmail.com> <455C2510.5000002@sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Return-path: Received: from mailhub.sw.ru ([195.214.233.200]:6545 "EHLO relay.sw.ru") by vger.kernel.org with ESMTP id S933525AbWKQMyt (ORCPT ); Fri, 17 Nov 2006 07:54:49 -0500 In-Reply-To: <455C2510.5000002@sw.ru> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: devel@openvz.org Cc: Tejun Heo , Jens Axboe , linux-kernel@vger.kernel.org, Bartlomiej Zolnierkiewicz , linux-ide@vger.kernel.org, Jeff Garzik , Alan Cox Vasily Averin wrote: > Tejun Heo wrote: >> Vasily Averin wrote: >>> I've reproduced this issue on linux 2.6.19-rc5 kernel. >>> >>> Please see http://bugzilla.kernel.org/show_bug.cgi?id=7518 for details >> >> Fortunately, libata is immune to the problem because it does >> ap->ops->irq_clear(ap) in ata_host_intr() regardless of command type in >> flight. So, not loading IDE piix and using libata to drive all piix >> ports solves the problem. > > I've disabled IDE support in the config and recompiled the kernel. > It seems you are right, problem go away, new kernel was booted without any > problems and works well. > > As a linux support engeneer I've seen this issue several times on the user-nodes > and it was very hard to understand what's happened and how to prevent this issue > in the future. First question is resolved now but from support point of view it > is very important to find some workaround against this issue on existing > distributions. Right now I see only one way: if this issue is detected on the > user node, we can add something like "ide=disable" into kernel commandline. I've tried to find the some work around for this issue. "hda=noprobe" helps, CD is not detected on the node and all other devices on the node works well... However if I have additional device who uses the same irq the issue returns back. When I enable USB support on my testnode, one of USB controllers requests the same IRQ line. And IRQ storm occurs again when I load uhci_hcd driver on the node. It is very strange for me: we do not have any IDE devices in this case. I would note, that I've seen the same behaviour when I detach the CDROM manually. I've updated the bug. Thank you, Vasily Averin