Re: [PATCH] x86: v3.4-rc1 s2ram regression

[Konstantin Khlebnikov <khlebnikov@openvz.org>]

Marcelo Tosatti wrote:
> On Sun, Apr 01, 2012 at 05:26:43PM +0400, Konstantin Khlebnikov wrote:
>> commit b74f05d61b73af584d0c39121980171389ecfaaa
>> ("x86: kvmclock: abstract save/restore sched_clock_state")
>> breaks s2ram for my notebook. It hangs (maybe panic) somewhere on resume stage
>> and blinks with all possible leds =) Screen is black, so I don't know what happened.
>>
>> reverting or following patch helps
>>
>> Bisected-by: Konstantin Khlebnikov<khlebnikov@openvz.org>
>> Cc: Thomas Gleixner<tglx@linutronix.de>
>> Cc: Marcelo Tosatti<mtosatti@redhat.com>
>> Cc: Avi Kivity<avi@redhat.com>
>> Cc: Igor Mammedov<imammedo@redhat.com>
>> ---
>>   arch/x86/power/cpu.c |    2 +-
>>   1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
>> index 4793683..2bc5a82 100644
>> --- a/arch/x86/power/cpu.c
>> +++ b/arch/x86/power/cpu.c
>> @@ -231,8 +231,8 @@ static void __restore_processor_state(struct saved_context *ctxt)
>>   /* Needed by apm.c */
>>   void restore_processor_state(void)
>>   {
>> -	x86_platform.restore_sched_clock_state();
>>   	__restore_processor_state(&saved_context);
>> +	x86_platform.restore_sched_clock_state();
>>   }
>>   #ifdef CONFIG_X86_32
>>   EXPORT_SYMBOL(restore_processor_state);
>
> The correct fix is in kvm.git (see below).

Thanks. Your patch works for me too.

>
> Ingo, can you please merge it through x86 tree while the
> kvm.git issues are resolved? It has been forward to you directly.
>
>      x86: call restore_sched_clock_state after %gs is initialized
>
>      restore_sched_clock_state methods use percpu data, therefore they
>      must run after %gs is initialized, but before mtrr_bp_restore (due to
>      lockstat using sched_clock).
>
>      Move it to the correct place.
>
>      Signed-off-by: Marcelo Tosatti<mtosatti@redhat.com>
>      Signed-off-by: Avi Kivity<avi@redhat.com>
>
>