Re: [PATCH 1/4] xen: disable non-boot VCPUs during suspend

From: David Vrabel
Date: Thu Jun 20 2013 - 06:01:32 EST


On 19/06/13 18:11, Konrad Rzeszutek Wilk wrote:
> On Wed, Jun 19, 2013 at 04:25:20PM +0100, David Vrabel wrote:
>> From: David Vrabel <david.vrabel@xxxxxxxxxx>
>>
>> syscore_suspend() and syscore_resume() expect there to be only one
>> online CPU. e.g., hrtimers_resume() only triggers events for the
>> current CPU. Xen's suspend path was leaving all VCPUs online and then
>> attempting to fixup problems afterwards (e.g., with an explicit call
>> to clock_was_set() to trigger pending high resolution timers).
>>
>> Instead, disable non-boot CPUs before calling stop_machine() and
>> reenable them afterwards.
>>
>> This is then similar to what the kexec code does before and after a
>> kexec jump (see kernel_kexec() in kernel/kexec.c).
>>
>> Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
>
> Looks like a bug-fix. But considering that the VCPU hotplug code
> in PVHVM had bugs in until v3.10 it probably shouldn't even hit
> stable tree.

I don't think actually fixes any bugs so it doesn't need to go to stable.

David
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