Re: [PATCH 3/3] KVM: s390: clear kicked_mask if not idle after set

Christian Borntraeger
2021-10-20T10:52:37Z

Am 20.10.21 um 12:45 schrieb Halil Pasic:
> On Wed, 20 Oct 2021 12:31:19 +0200
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>
>>> Before releasing something like this, where none of us is sure if
>>> it really saves cpu cost, I'd prefer to run some measurement with
>>> the whole kicked_mask logic removed and to compare the number of
>>> vcpu wake ups with the number of interrupts to be processed by
>>> the gib alert mechanism in a slightly over committed host while
>>> driving with Matthews test load.
>>
>> But I think patch 1 and 2 can go immediately as they measurably or
>> testable fix things. Correct?
>
> I think so as well. And if patch 3 is going to be dropped, I would
> really like to keep the unconditional clear in kvm_arch_vcpu_runnable(),
> as my analysis in the discussion points out: I think it can save us
> form trouble this patch is trying to address.

Yes, lets keep patch 1 and 2 as us and let us look deeper into this patch.
I will apply and queue 1 and 2 soon.