Re: [PATCH 3/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap

[Alexander Duyck <alexander.duyck@gmail.com>]

On Wed, Sep 12, 2018 at 8:54 AM Pasha Tatashin
<Pavel.Tatashin@microsoft.com> wrote:
>
>
>
> On 9/12/18 11:48 AM, Alexander Duyck wrote:
> > On Wed, Sep 12, 2018 at 6:59 AM Pasha Tatashin
> > <Pavel.Tatashin@microsoft.com> wrote:
> >>
> >> Hi Alex,
> >
> > Hi Pavel,
> >
> >> Please re-base on linux-next,  memmap_init_zone() has been updated there
> >> compared to mainline. You might even find a way to unify some parts of
> >> memmap_init_zone and memmap_init_zone_device as memmap_init_zone() is a
> >> lot simpler now.
> >
> > This patch applied to the linux-next tree with only a little bit of
> > fuzz. It looks like it is mostly due to some code you had added above
> > the function as well. I have updated this patch so that it will apply
> > to both linux and linux-next by just moving the new function to
> > underneath memmap_init_zone instead of above it.
> >
> >> I think __init_single_page() should stay local to page_alloc.c to keep
> >> the inlining optimization.
> >
> > I agree. In addition it will make pulling common init together into
> > one space easier. I would rather not have us create an opportunity for
> > things to further diverge by making it available for anybody to use.
> >
> >> I will review you this patch once you send an updated version.
> >
> > Other than moving the new function from being added above versus below
> > there isn't much else that needs to change, at least for this patch. I
> > have some follow-up patches I am planning that will be targeted for
> > linux-next. Those I think will focus more on what you have in mind in
> > terms of combining this new function
>
> Hi Alex,
>
> I'd like see the combining to be part of the same series. May be this
> patch can be pulled from this series and merged with your upcoming
> patches series?
>
> Thank you,
> Pavel

The problem is the issue is somewhat time sensitive, and the patches I
put out in this set needed to be easily backported. That is one of the
reasons this patch set is as conservative as it is.

I was hoping to make 4.20 with this patch set at the latest. My
follow-up patches are more of what I would consider 4.21 material as
it will be something we will probably want to give some testing time,
and I figure there will end up being a few revisions. I would probably
have them ready for review in another week or so.

Thanks.

- Alex