Re: [PATCH 00/17] Paravirt CPUs and push task for less vCPU preemption

[Yury Norov <yury.norov@gmail.com>]

On Fri, Dec 05, 2025 at 11:00:18AM +0530, Shrikanth Hegde wrote:
> 
> 
> On 12/4/25 6:58 PM, Ilya Leoshkevich wrote:
> > On Wed, 2025-11-19 at 18:14 +0530, Shrikanth Hegde wrote:

...

> > Others have already commented on the naming, and I would agree that
> > "paravirt" is really misleading. I cannot say that the previous "cpu-
> > avoid" one was perfect, but it was much better.
 
It was my suggestion to switch names. cpu-avoid is definitely a
no-go. Because it doesn't explain anything and only confuses.

I suggested 'paravirt' (notice - only suggested) because the patch
series is mainly discussing paravirtualized VMs. But now I'm not even
sure that the idea of the series is:

1. Applicable only to paravirtualized VMs; and 
2. Preemption and rescheduling throttling requires another in-kernel
   concept other than nohs, isolcpus, cgroups and similar.

Shrikanth, can you please clarify the scope of the new feature? Would
it be useful for non-paravirtualized VMs, for example? Any other
task-cpu bonding problems?

On previous rounds you tried to implement the same with cgroups, as
far as I understood. Can you discuss that? What exactly can't be done
with the existing kernel APIs?

Thanks,
Yury

> > [1] https://github.com/iii-i/linux/commits/iii/poc/cpu-avoid/v3/
> 
> Will look into it. one thing to to be careful are CPU numbers.