Re: [PATCH 2/5] x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader

From: Andy Lutomirski
Date: Fri Dec 11 2015 - 13:03:49 EST


On Fri, Dec 11, 2015 at 12:42 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
>
> On 11/12/2015 08:52, Ingo Molnar wrote:
>>
>> * Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:

>>>
>>> Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>>
>> Thanks. I've added your Reviewed-by to the 1/5 patch as well - to be able to put
>> the whole series into the tip:x86/entry tree. Let me know if you'd like it to be
>> done differently.
>
> The 1/5 patch is entirely in KVM and is not necessary for the rest of
> the series to work. I would like it to be separate, because Marcelo has
> not yet chimed in to say why it was necessary.
>
> Can you just apply patches 2-5?

Yes, please. I don't grok the clock update mechanism in the KVM host
well enough to be sure that patch 1 is actually correct. All I know
is that it works better on my laptop with the patch than without the
patch and that it seems at least conceptually correct.

In any event, patch 1 is a host patch and 2-5 are guest patches, and
they only interact to the extent that it's hard for me to test 2-5 on
the guest without patch 1 on the host because without patch 1 my
laptop's host kernel tends to disable stable kvmclock, thus disabling
the entire mechanism in the guest.

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/