Re: [PATCH v3 00/28] hugetlb/CMA improvements for large systems

From: Andrew Morton
Date: Mon Feb 10 2025 - 18:29:04 EST


On Mon, 10 Feb 2025 10:56:50 -0800 Frank van der Linden <fvdl@xxxxxxxxxx> wrote:

> > Hi Frank,
> >
> > While I plan to keep reviewing the series, I think it would make sense
> > to split this patchset into two smaller ones.
> > The way I see it, we are trying to deal with two different problems and their
> > solutions.
> >
> > 1) pre-hvo at boot time
> > 2) multi-range support of CMA (only used for hugetlb)
> >
> > I did not go through the entire patchset yet, so I ignore whether the
> > respective patches to tackle these two problems are really dependent on
> > each other, but I think that would be very interesting to consider a
> > patchset per solution if that is not the case.
> >
> > IMHO, it would ease review quite a lot.
>
> Hi Oskar,
>
> Thanks a lot for reviewing this series.
>
> I certainly could split it up, but here are the dependencies (it's
> actually 3 parts):
>
> 1. Multi-range CMA (used by hugetlb) (patches 1-4)
> 2. Pre-HVO for hugetlb bootmem pages (patches 5-22)
> 3. Enable hugepages= (and pre-HVO) for CMA (patches 23-28)
>
> 1 and 2 are independent. 3 depends on 1 and 2.
>
> So, I could post 1) and 2) simultaneously, and 3) would have to wait
> until 1) and 2) are resolved.
>
> Andrew, do you have any thoughts on splitting it up?

I don't see much trouble with the above dependencies - we can consider
the three series to be an all-or-nothing thing.

Such a splitup would be the same patches, packaged slightly
differently. The main difference would be the presence of two more
[0/n] cover letters, presumably also repackaging existing material. I
don't see a lot of benefit personally.