From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934671AbXILQER (ORCPT ); Wed, 12 Sep 2007 12:04:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932502AbXILQEF (ORCPT ); Wed, 12 Sep 2007 12:04:05 -0400 Received: from rgminet01.oracle.com ([148.87.113.118]:42878 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764771AbXILQEE (ORCPT ); Wed, 12 Sep 2007 12:04:04 -0400 Date: Wed, 12 Sep 2007 09:01:51 -0700 From: Randy Dunlap To: Jesse Barnes Cc: Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: Lossy interrupts on x86_64 Message-Id: <20070912090151.97c9a78e.randy.dunlap@oracle.com> In-Reply-To: <200709120833.15980.jbarnes@virtuousgeek.org> References: <200709120833.15980.jbarnes@virtuousgeek.org> Organization: Oracle Linux Eng. X-Mailer: Sylpheed 2.4.2 (GTK+ 2.8.10; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 12 Sep 2007 08:33:15 -0700 Jesse Barnes wrote: > I just narrowed down a weird problem where I was losing more than 50% of > my vblank interrupts to what seems to be the hires timers patch. Stock > 2.6.23-rc5 works fine, but the latest (171) kernel from rawhide drops > most of my interrupts unless I also have another interrupt source > running (e.g. if I hold down a key or move the mouse I get the expected > number of vblank interrupts, otherwise I get between 3 and 30 instead > of the expected 60 per second). > > Any ideas? It seems like it might be bad APIC programming, but I > haven't gone through those mods to look for suspects... Also tickless? (NO_HZ ?) I think I've seen some emails about tickless and keystrokes being needed to cause interrupts... but I'm not postive about it. but you said "any ideas" --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code ***