Re: [PATCH -v2 0/9] mm: make movable onlining suck less

From: Michal Hocko
Date: Mon Apr 10 2017 - 13:53:43 EST


On Mon 10-04-17 12:35:53, Jerome Glisse wrote:
> On Mon, Apr 10, 2017 at 01:03:42PM +0200, Michal Hocko wrote:
> > Hi,
> > The last version of this series has been posted here [1]. It has seen
> > some more serious testing (thanks to Reza Arbab) and fixes for the found
> > issues. I have also decided to drop patch 1 [2] because it turned out to
> > be more complicated than I initially thought [3]. Few more patches were
> > added to deal with expectation on zone/node initialization.
> >
> > I have rebased on top of the current mmotm-2017-04-07-15-53. It
> > conflicts with HMM because it touches memory hotplug as
> > well. We have discussed [4] with Jérôme and he agreed to
> > rebase on top of this rework [5] so I have reverted his series
> > before applyig mine. I will help him to resolve the resulting
> > conflicts. You can find the whole series including the HMM revers in
> > git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git branch
> > attempts/rewrite-mem_hotplug
> >
>
> So updated HMM patchset :
> https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-v20
>
> I am not posting yet as it seems there is couple thing you need to
> fix in your patchset first. However if you could review :

I assume I will resubmit v3 after all the feedback is addressed here.

> https://cgit.freedesktop.org/~glisse/linux/commit/?h=hmm-v20&id=84fc68534e781cf6125d02b3bfdba4a51e82d9c9
>
> As it was your idea, i just want to make sure i didn't denatured
> it :)

OK, looks good to me. I would be more specific in the changelog though.
"
mm, memory_hotplug: introduce add_pages

There are new users of memory hotplug emerging. Some of them require
different subset of arch_add_memory. There are some which only require
allocation of struct pages without mapping those pages to the kernel
address space. We currently have __add_pages for that purpose. But this
is rather lowlevel and not very suitable for the code outside of the
memory hotplug. E.g. x86_64 wants to update max_pfn which should be
done by the caller. Introduce add_pages() which should care about those
details if they are needed. Each architecture should define its
implementation and select CONFIG_ARCH_HAS_ADD_PAGES. All others use
the currently existing __add_pages.
"

--
Michal Hocko
SUSE Labs