Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754340AbXEXVP1 (ORCPT ); Thu, 24 May 2007 17:15:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752833AbXEXVPS (ORCPT ); Thu, 24 May 2007 17:15:18 -0400 Received: from sj-iport-2-in.cisco.com ([171.71.176.71]:34060 "EHLO sj-iport-2.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751491AbXEXVPQ (ORCPT ); Thu, 24 May 2007 17:15:16 -0400 X-IronPort-AV: i="4.14,575,1170662400"; d="scan'208"; a="376024274:sNHT44246458" To: Andrew Morton Cc: Ben Collins , linux-kernel@vger.kernel.org, Zachary Amsden Subject: Re: [PATCH 4/6] RTC: Ratelimit "lost interrupts" message X-Message-Flag: Warning: May contain useful information References: <98cd38b5.git.bcollins@ubuntu.com> <20070524134822.ed020127.akpm@linux-foundation.org> <1180040212.12570.279.camel@cunning> <20070524140956.12ff7c99.akpm@linux-foundation.org> From: Roland Dreier Date: Thu, 24 May 2007 14:15:12 -0700 In-Reply-To: <20070524140956.12ff7c99.akpm@linux-foundation.org> (Andrew Morton's message of "Thu, 24 May 2007 14:09:56 -0700") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) XEmacs/21.4.19 (linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 24 May 2007 21:15:14.0605 (UTC) FILETIME=[9F046DD0:01C79E48] Authentication-Results: sj-dkim-1; header.From=rdreier@cisco.com; dkim=pass ( sig from cisco.com/sjdkim1004 verified; ); Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1036 Lines: 21 > > I got it a lot when using any sort of virtualization on my Core2Duo > > (kvm, vmware, qemu). Just a big spew. Honestly, I was getting this with > > 2.6.20, and haven't tested again with latest kernel. > > OK, a bit of googling finds things like this: > http://chxo.com/be2/20060821_3333.html, so I assume that it's some sort of > generic problem with the hypervisor's emulation of the RTC. Actually I saw this "lost interrupts" spew on the host (ie the non-virtualized kernel) running just plain qemu (no kvm or anything scary like that). It seemed to be some long irqs-off latency in the tun/tap or bridging code (it went away when I stopped using "-net tap" on the qemu command line), but I never succeeded in getting Ingo's latency tracer to be able to track it down. - R. - 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/