Re: x86: kvmclock: abstract save/restore sched_clock_state

[Igor Mammedov <imammedo@redhat.com>]

On 02/10/2012 01:33 PM, Marcelo Tosatti wrote:
> On Fri, Feb 10, 2012 at 10:32:16AM -0200, Marcelo Tosatti wrote:
>> On Fri, Feb 10, 2012 at 03:32:11PM +0530, Amit Shah wrote:
>>> On (Thu) 09 Feb 2012 [16:13:29], Igor Mammedov wrote:
>>>
>>>> Stalls are probably caused by uninitialized percpu hv_clock, with
>>>> following patch I don't see stalls. Although I might be just lucky.
>>>> http://git.kernel.org/?p=virt/kvm/kvm.git;a=commit;h=e2971ac7e1d186af059e088d305496c5cb47d487
>>>
>>> Your commit does make things better, I don't see any stalls on the
>>> first resume.
>>>
>>> However, a subsequent s4 causes the stall to re-appear on resume, and
>>> this time there are no stall messages; the kernel just sits there
>>> spinning on something.  I've not found the solution to this one yet (I
>>> had a commit similar to Marcelo's in the works, which got me to the
>>> previous works-but-stalls behaviour).
>>
>> I cannot reproduce it here. Suspend/resume are operating normally after
>> several iterations. Igor do you see anything similar?

I wasn't able to reproduce it either but I haven't tried with Amit's config
yet.

>>
>> Amit, can you please enable CONFIG_PRINTK_TIME=y and post a full dmesg
>> (both during suspend and also the new kernel during resume).
>
> Also is it reproducible with UP guest?

Another thing is to try smp guest without kvmclock and see if it helps.
It might be just something else.

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-- 
Thanks,
  Igor