From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: broken timer Date: Mon, 27 Jul 2009 15:05:40 -0300 Message-ID: <20090727180540.GG4776@poweredge.glommer> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: avi@redhat.com To: kvm@vger.kernel.org Return-path: Received: from mx2.redhat.com ([66.187.237.31]:53372 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403AbZG0R6l (ORCPT ); Mon, 27 Jul 2009 13:58:41 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n6RHwgCb029714 for ; Mon, 27 Jul 2009 13:58:42 -0400 Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: Hello, goodfellas I'm seeing a strange problem in our much loved qemu-kvm.git It's been there before avi left for vacation, at least. The worst part, is that it doesn't happen always, and I don't even think it is deterministic in its nature, IOW, there was nothing I could do to make it more or less likely to happen. It's almost obviously interrupt related, but I can't determine more than that As I haven't, and won't have the time to debug this in the near future, here's the riddle for you all to appreciate: ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 CPU0: QEMU Virtual CPU version 0.10.50 stepping 03 Using local APIC timer interrupts. Detected 0.000 MHz APIC timer. ------------[ cut here ]------------ WARNING: at kernel/time/clockevents.c:46 clockevent_delta2ns+0x37/0x72() (Not tainted) Modules linked in: Pid: 1, comm: swapper Not tainted 2.6.27.5-117.fc10.x86_64 #1 Call Trace: [] warn_on_slowpath+0x60/0x90 [] ? trace_hardirqs_on_thunk+0x3a/0x3c [] ? early_idt_handler+0x0/0x72 [] ? printk+0x3c/0x3e [] clockevent_delta2ns+0x37/0x72 [] setup_boot_APIC_clock+0x1c2/0x24b [] ? printk+0x3c/0x3e [] native_smp_prepare_cpus+0x29e/0x2cf [] kernel_init+0x59/0x214 [] ? trace_hardirqs_on_thunk+0x3a/0x3c [] child_rip+0xa/0x11 [] ? restore_args+0x0/0x30 [] ? kernel_init+0x0/0x214 [] ? child_rip+0x0/0x11 ---[ end trace 4eaa2a86a8e2da22 ]--- APIC frequency too slow, disabling apic timer