Re: Lag after resume culprit found

From: Andriy Gapon <avg_at_FreeBSD.org> Date: Thu, 17 May 2018 10:56:53 +0300 · This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:16 UTC

On 17/05/2018 10:46, Johannes Lundberg wrote:
> On Thu, May 17, 2018 at 7:43 AM, Andriy Gapon <avg_at_freebsd.org
> <mailto:avg_at_freebsd.org>> wrote:
> 
>     On 17/05/2018 02:07, Johannes Lundberg wrote:
>     > https://github.com/freebsd/freebsd/commit/66f063557f257baa9c8aeab9f933171eaa6e1cfa
>     <https://github.com/freebsd/freebsd/commit/66f063557f257baa9c8aeab9f933171eaa6e1cfa>
>     > x86 cpususpend_handler: call wbinvd after setting suspend state bits
> 
>     That's very interesting and surprising.
>     That commit changes something that happens before suspend, it should not have
>     any effect on the system state after resume.
> 
>     Does anyone have a theory of what could be wrong?
> 
> Nope but moving
>         CPU_CLR_ATOMIC(cpu, &suspended_cpus);
> back to the end of that scope fixes it.

That's interesting.
Thank you for testing it!
And let me think about it.

>     > How to test (i915kms)
>     >
>     > Start X with glxgears
>     > Confirm running stable at 60 fps
>     > suspend/resume (S3)
>     > glxgears is now fluctuating between 10-40 fps.

-- 
Andriy Gapon