On Thu 14-11-19 14:19:11, David Hildenbrand wrote:
> Now that the memory isolate notifier is gone, the parameter is always 0.
> Drop it and cleanup has_unmovable_pages().
>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> Cc: Qian Cai <cai@xxxxxx>
> Cc: Pingfan Liu <kernelfans@xxxxxxxxx>
> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> Cc: Vlastimil Babka <vbabka@xxxxxxx>
> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
> Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
> Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Cc: Alexander Potapenko <glider@xxxxxxxxxx>
> Cc: Arun KS <arunks@xxxxxxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
yay again! I have to say that this was a head scratcher when I've seen
that for the first time. It is really great to see it go
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!
> ---
> include/linux/page-isolation.h | 4 ++--
> mm/memory_hotplug.c | 2 +-
> mm/page_alloc.c | 21 +++++++--------------
> mm/page_isolation.c | 2 +-
> 4 files changed, 11 insertions(+), 18 deletions(-)
>
> diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
> index 6861df759fad..148e65a9c606 100644
> --- a/include/linux/page-isolation.h
> +++ b/include/linux/page-isolation.h
> @@ -33,8 +33,8 @@ static inline bool is_migrate_isolate(int migratetype)
> #define MEMORY_OFFLINE 0x1
> #define REPORT_FAILURE 0x2
>
> -bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> - int migratetype, int flags);
> +bool has_unmovable_pages(struct zone *zone, struct page *page, int migratetype,
> + int flags);
> void set_pageblock_migratetype(struct page *page, int migratetype);
> int move_freepages_block(struct zone *zone, struct page *page,
> int migratetype, int *num_movable);
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 3b5cee4d3f4e..f06d33748607 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1158,7 +1158,7 @@ static bool is_pageblock_removable_nolock(unsigned long pfn)
> if (!zone_spans_pfn(zone, pfn))
> return false;
>
> - return !has_unmovable_pages(zone, page, 0, MIGRATE_MOVABLE,
> + return !has_unmovable_pages(zone, page, MIGRATE_MOVABLE,
> MEMORY_OFFLINE);
> }
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index f5ecbacb0e04..e4d8f3a1a6b6 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8270,17 +8270,15 @@ void *__init alloc_large_system_hash(const char *tablename,
>
> /*
> * This function checks whether pageblock includes unmovable pages or not.
> - * If @count is not zero, it is okay to include less @count unmovable pages
> *
> * PageLRU check without isolation or lru_lock could race so that
> * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
> * check without lock_page also may miss some movable non-lru pages at
> * race condition. So you can't expect this function should be exact.
> */
> -bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> - int migratetype, int flags)
> +bool has_unmovable_pages(struct zone *zone, struct page *page, int migratetype,
> + int flags)
> {
> - unsigned long found;
> unsigned long iter = 0;
> unsigned long pfn = page_to_pfn(page);
> const char *reason = "unmovable page";
> @@ -8306,13 +8304,11 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> goto unmovable;
> }
>
> - for (found = 0; iter < pageblock_nr_pages; iter++) {
> - unsigned long check = pfn + iter;
> -
> - if (!pfn_valid_within(check))
> + for (; iter < pageblock_nr_pages; iter++) {
> + if (!pfn_valid_within(pfn + iter))
> continue;
>
> - page = pfn_to_page(check);
> + page = pfn_to_page(pfn + iter);
>
> if (PageReserved(page))
> goto unmovable;
> @@ -8361,11 +8357,9 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
> continue;
>
> - if (__PageMovable(page))
> + if (__PageMovable(page) || PageLRU(page))
> continue;
>
> - if (!PageLRU(page))
> - found++;
> /*
> * If there are RECLAIMABLE pages, we need to check
> * it. But now, memory offline itself doesn't call
> @@ -8379,8 +8373,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
> * is set to both of a memory hole page and a _used_ kernel
> * page at boot.
> */
> - if (found > count)
> - goto unmovable;
> + goto unmovable;
> }
> return false;
> unmovable:
> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> index 21af88b718aa..1f8b9dfecbe8 100644
> --- a/mm/page_isolation.c
> +++ b/mm/page_isolation.c
> @@ -37,7 +37,7 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_
> * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
> * We just check MOVABLE pages.
> */
> - if (!has_unmovable_pages(zone, page, 0, migratetype, isol_flags)) {
> + if (!has_unmovable_pages(zone, page, migratetype, isol_flags)) {
> unsigned long nr_pages;
> int mt = get_pageblock_migratetype(page);
>
> --
> 2.21.0
--
Michal Hocko
SUSE Labs
