[PATCH v1 12/12] mm: remove "count" parameter from has_unmovable_pages()

David Hildenbrand
2019-10-31T14:30:56Z

Now that the memory isolate notifier is gone, the parameter is always 0.
Drop it and cleanup has_unmovable_pages().

Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Arun KS <arunks@codeaurora.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
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 561371ead39a..81e38e699e23 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1149,7 +1149,7 @@ 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 12f3ce09d33d..efcce493452c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8182,17 +8182,15 @@ 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";
@@ -8218,13 +8216,11 @@ 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;
@@ -8273,11 +8269,9 @@ 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
@@ -8291,8 +8285,7 @@ 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 20d87d18c7cc..c0ecae9f5f93 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))
ret = 0;

/*
--
2.21.0