Re: [PATCH v3] srcu: Reduce blocking agressiveness of expedited grace periods further

From: Marc Zyngier
Date: Wed Jul 20 2022 - 03:19:39 EST


Hi Paul,

On Tue, 19 Jul 2022 18:15:47 +0100,
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:
>
> On Tue, Jul 19, 2022 at 09:25:56AM +0100, Marc Zyngier wrote:
> >
> > Is there any chance for this fix to make it into 5.19? The regression
> > is significant enough on low-end systems, and I'd rather see it
> > addressed.
>
> I wasn't planning on it, based on my (possibly quite flawed) assumption
> that it affected only embedded systems running in a virtual environment.

Not quite. This affects any system running virtual machines based on
KVM and using QEMU as the VMM (the machines I run this on don't quite
qualify as "embedded").

> My plan was to send it in my pull request for the next merge window
> next week. My pull request is next week, yes, the merge window opens
> the following Sunday. ;-)
>
> It has a Fixes tag, so it will be backported.
>
> But if it is important to get it into v5.19 rather than v5.19.x for small
> "x", please let me know and I will see what Linus does with the resulting
> v5.19-rc7 pull request.

I think that the sooner we address this in an upstream kernel, the
better, and I'd definitely support you sending this to Linus for -rc7!

Thanks,

M.

--
Without deviation from the norm, progress is not possible.