From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [Bug #13116] Can't boot with nosmp Date: Tue, 9 Jun 2009 13:58:46 -0700 Message-ID: <20090609135846.43260595@nehalam> References: <20090608091544.53a94235@nehalam> <20090608170437.1c2386a5@nehalam> <4A2EAA53.7060006@redhat.com> <20090609113656.46ed6335@nehalam> <4A2EAD2F.5010505@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4A2EAD2F.5010505-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Avi Kivity Cc: Dan Williams , Rusty Russell , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List On Tue, 09 Jun 2009 21:42:55 +0300 Avi Kivity wrote: > Stephen Hemminger wrote: > > > > >> This only affects reboots. But yes, the cpumask code has bugs. Does > >> the .config involved select MAXSMP? > >> > >> > > > > Patch does not fix the problem. Not sure if it is KVM only problem. > > Look like possible cpumask always equals what ACPI / SMP tables report. > > So currently looking into alloc_percpu which may not handle the possible > > but never used cpus. > > > > > > Right, it shouldn't have. > > > It is x86-64 config and does not have MAXSMP set. It does have NR_CPUS set. > > > > So it's not cpumask. Dare I suggest a bisect? > I did some testing of different versions. * Problem does not exist with 2.6.30-rc8 (so regression should be closed). * Problem does exist with 2.6.29.4 * Happens with both nosmp and maxcpus=1 Given that it is fixed in 2.6.30, at this point there really is no urgency to spend more time investigating the issue. There are certainly bigger problems to deal with. --