Messages in this thread | | | Date | Tue, 09 Jun 2009 21:30:43 +0300 | From | Avi Kivity <> | Subject | Re: [Bug #13116] Can't boot with nosmp |
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Dan Williams wrote: > On Mon, Jun 8, 2009 at 5:04 PM, Stephen Hemminger<shemminger@vyatta.com> wrote: > >> I did some more debugging, and the problem appears to be that >> booting with nosmp still leaves all the CPU's present in the cpu >> possible mask. So code like dma engine (or loopback device), that >> use alloc_percpu get broken. >> >> Not sure why all the cpu's are still showing up in the possible mask. >> Rusty? do you have an answer. >> > > Would this recent commit also fix this issue? > > commit a4c0364be3f43d3e17fe19270f8b3d64881606e6 > Author: Avi Kivity <avi@redhat.com> > Date: Sat Jun 6 12:34:39 2009 +0300 > > KVM: Explicity initialize cpus_hardware_enabled > > Under CONFIG_MAXSMP, cpus_hardware_enabled is allocated from the heap and > not statically initialized. This causes a crash on reboot when kvm thinks > vmx is enabled on random nonexistent cpus and accesses nonexistent percpu > lists. > > Fix by explicitly clearing the variable. > > Cc: stable@kernel.org > Reported-and-tested-by: Yinghai Lu <yinghai@kernel.org> > Signed-off-by: Avi Kivity <avi@redhat.com> >
This only affects reboots. But yes, the cpumask code has bugs. Does the .config involved select MAXSMP?
-- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
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