On Wed, Jan 12, 2022 at 11:54:49AM +0100, David Hildenbrand wrote:
> On 05.01.22 22:47, Zi Yan wrote:
> > From: Zi Yan <z...@nvidia.com>
> >
> > This is done in addition to MIGRATE_ISOLATE pageblock merge avoidance.
> > It prepares for the upcoming removal of the MAX_ORDER-1 alignment
> > requirement for CMA and alloc_contig_range().
> >
> > MIGRARTE_HIGHATOMIC should not merge with other migratetypes like
> > MIGRATE_ISOLATE and MIGRARTE_CMA[1], so this commit prevents that too.
> > Also add MIGRARTE_HIGHATOMIC to fallbacks array for completeness.
> >
> > [1]
> > https://lore.kernel.org/linux-mm/20211130100853.gp3...@techsingularity.net/
> >
> > Signed-off-by: Zi Yan <z...@nvidia.com>
> > ---
> > include/linux/mmzone.h | 6 ++++++
> > mm/page_alloc.c | 28 ++++++++++++++++++----------
> > 2 files changed, 24 insertions(+), 10 deletions(-)
> >
...
> > @@ -3545,8 +3553,8 @@ int __isolate_free_page(struct page *page, unsigned
> > int order)
> > struct page *endpage = page + (1 << order) - 1;
> > for (; page < endpage; page += pageblock_nr_pages) {
> > int mt = get_pageblock_migratetype(page);
> > - if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
> > - && !is_migrate_highatomic(mt))
> > + /* Only change normal pageblock */
> > + if (migratetype_has_fallback(mt))
> > set_pageblock_migratetype(page,
> > MIGRATE_MOVABLE);
> > }
>
> That part is a nice cleanup IMHO. Although the "has fallback" part is a
> bit imprecise. "migratetype_is_mergable()" might be a bit clearer.
> ideally "migratetype_is_mergable_with_other_types()". Can we come up
> with a nice name for that?
migratetype_is_mergable() kinda implies "_with_other_types", no?
I like migratetype_is_mergable() more than _has_fallback().
My $0.02 to bikeshedding :)
> --
> Thanks,
>
> David / dhildenb
>
>
--
Sincerely yours,
Mike.
