From mboxrd@z Thu Jan 1 00:00:00 1970
From: bugzilla-daemon@bugzilla.kernel.org
Subject: [Bug 75331] New: "soft lockup CPU#0 stuck for 23s" regression on
32bit 3.13.0+ kernels.
Date: Fri, 02 May 2014 22:35:18 +0000
Message-ID:
Mime-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
To: kvm@vger.kernel.org
Return-path:
Received: from mail.kernel.org ([198.145.19.201]:43234 "EHLO mail.kernel.org"
rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
id S1751655AbaEBWfW (ORCPT );
Fri, 2 May 2014 18:35:22 -0400
Received: from mail.kernel.org (localhost [127.0.0.1])
by mail.kernel.org (Postfix) with ESMTP id 7C473203AC
for ; Fri, 2 May 2014 22:35:21 +0000 (UTC)
Received: from bugzilla2.web.kernel.org (bugzilla2.web.kernel.org [172.20.200.52])
by mail.kernel.org (Postfix) with ESMTP id E63F72038D
for ; Fri, 2 May 2014 22:35:18 +0000 (UTC)
Sender: kvm-owner@vger.kernel.org
List-ID:
https://bugzilla.kernel.org/show_bug.cgi?id=75331
Bug ID: 75331
Summary: "soft lockup CPU#0 stuck for 23s" regression on 32bit
3.13.0+ kernels.
Product: Virtualization
Version: unspecified
Kernel Version: 3.13.0+
Hardware: All
OS: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: kvm
Assignee: virtualization_kvm@kernel-bugs.osdl.org
Reporter: iive@yahoo.com
Regression: No
Created attachment 134761
--> https://bugzilla.kernel.org/attachment.cgi?id=134761&action=edit
dmesg log and kernel .config
I'm getting "soft lockup CPU#0 stuck for 23s" when running qemu 1.7.0 with kvm
on vanilla kernels 3.13.0 and above. All builds are 32 bit.
The lockup happens shortly after starting the guest OS, sometimes even before
the guest boot is complete. The cpu graph shows one core running in kernel
mode, the guest freezes, qemu is still responsive. Sometimes the lockup goes
away after a while, then comes back.
The first time I didn't kill qemu and it managed to lock my system.
I'm not using virtio/xen or other frameworks. Just bare qemu. I've tried to
remove network and sound devices but it had no measurable impact. Having -usb
and -smp 4 seems to make triggering the lockup much easier/faster but removing
them doesn't eliminate lockups. (Or lockups may be random and not related to
these options.)
With some help, I started a `git bisect` on the Linus' repository. I did manage
to locate a commit that when reversed eliminates the problem completely (tested
on 3.14.1 kernel that previously had this problem).
The commit is :
---------
commit e0f6dec35f9286e78879fe1ac92803fd69fc4fdc
Author: H. Peter Anvin
Date: Wed Dec 4 14:31:28 2013 -0800
x86, bitops: Correct the assembly constraints to testing bitops
---------
I'm with gcc-4.8.2 on latest Slackware.
To this bugreport I'm attaching tgz archive with the 3.14.0 kernel `.config`
file and `dmesg` extracted from the vmcore.
On request I could provide vmcore and vmlinux of 3.14.0 compiled with debug
info. (75MB each, when gzipped/stripped by `makedumpfile`)
Qemu is compiled with: ./configure --disable-strip
--audio-drv-list=oss,alsa,sdl --disable-bsd-user --enable-vnc
--target-list=i386-softmmu,i386-linux-user
Qemu is started with : qemu -smp 4 -usb -enable-kvm -vga cirrus -net none
-ctrl-grab -display sdl -hda guest.qcow2
--
You are receiving this mail because:
You are watching the assignee of the bug.