Re: [RFC PATCH 0/5] mm, hugetlb: allocation API and migration improvements

From: Michal Hocko
Date: Fri Dec 15 2017 - 04:33:38 EST


Naoya,
this has passed Mike's review (thanks for that!), you have mentioned
that you can pass this through your testing machinery earlier. While
I've done some testing already I would really appreciate if you could
do that as well. Review would be highly appreciated as well.

Thanks!

On Mon 04-12-17 15:01:12, Michal Hocko wrote:
> Hi,
> this is a follow up for [1] for the allocation API and [2] for the
> hugetlb migration. It wasn't really easy to split those into two
> separate patch series as they share some code.
>
> My primary motivation to touch this code is to make the gigantic pages
> migration working. The giga pages allocation code is just too fragile
> and hacked into the hugetlb code now. This series tries to move giga
> pages closer to the first class citizen. We are not there yet but having
> 5 patches is quite a lot already and it will already make the code much
> easier to follow. I will come with other changes on top after this sees
> some review.
>
> The first two patches should be trivial to review. The third patch
> changes the way how we migrate huge pages. Newly allocated pages are a
> subject of the overcommit check and they participate surplus accounting
> which is quite unfortunate as the changelog explains. This patch doesn't
> change anything wrt. giga pages.
> Patch #4 removes the surplus accounting hack from
> __alloc_surplus_huge_page. I hope I didn't miss anything there and a
> deeper review is really due there.
> Patch #5 finally unifies allocation paths and giga pages shouldn't be
> any special anymore. There is also some renaming going on as well.
>
> Shortlog
> Michal Hocko (5):
> mm, hugetlb: unify core page allocation accounting and initialization
> mm, hugetlb: integrate giga hugetlb more naturally to the allocation path
> mm, hugetlb: do not rely on overcommit limit during migration
> mm, hugetlb: get rid of surplus page accounting tricks
> mm, hugetlb: further simplify hugetlb allocation API
>
> Diffstat:
> include/linux/hugetlb.h | 3 +
> mm/hugetlb.c | 305 +++++++++++++++++++++++++++---------------------
> mm/migrate.c | 3 +-
> 3 files changed, 175 insertions(+), 136 deletions(-)
>
>
> [1] http://lkml.kernel.org/r/20170622193034.28972-1-mhocko@xxxxxxxxxx
> [2] http://lkml.kernel.org/r/20171122152832.iayefrlxbugphorp@xxxxxxxxxxxxxx
>
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--
Michal Hocko
SUSE Labs