Re: [External] Re: [PATCH v2] mm: add new syscall pidfd_set_mempolicy().

From: Michal Hocko
Date: Tue Nov 22 2022 - 03:40:23 EST


On Tue 22-11-22 16:33:09, Zhongkun He wrote:
> Hi Michal, thanks for your replay and suggestions.
>
> >
> > Yes the memory consumption is going to increase but the question is
> > whether this is something that is a real problem. Is it really common to
> > have many vmas with a dedicated policy?
>
> Yes, it does not a realy problem.
>
> >
> > What I am arguing here is that there are essentially 2 ways forward.
> > Either we continue to build up on top of the existing and arguably very
> > fragile code and make it even more subtle or follow a general pattern of
> > a proper reference counting (with usual tricks to reduce cache line
> > bouncing and similar issues). I do not really see why memory policies
> > should be any different and require very special treatment.
> >
>
> I got it. It is rather subtle and easy to get wrong if we push forward
> with the existing way and it is a good opportunity to get from the
> existing subtle model. I will try that on next version.

Thanks for being receptive to the review feedback!
--
Michal Hocko
SUSE Labs