[RFC PATCH 4/4] mm/page_isolation: remove migratetype parameter from more functions.

[Zi Yan <ziy@nvidia.com>]

migratetype is no longer overwritten during pageblock isolation,
start_isolate_page_range(), has_unmovable_pages(), and
set_migratetype_isolate() no longer need which migratetype to restore
during isolation failure. For has_unmoable_pages(), it needs to know if
the isolation is for CMA allocation, so adding CMA_ALLOCATION to isolation
flags to provide the information.

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
 include/linux/page-isolation.h |  3 ++-
 mm/memory_hotplug.c            |  1 -
 mm/page_alloc.c                |  4 +++-
 mm/page_isolation.c            | 27 +++++++++++----------------
 4 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index c2a1bd621561..e94117101b6c 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -32,13 +32,14 @@ static inline bool is_migrate_isolate(int migratetype)
 
 #define MEMORY_OFFLINE	0x1
 #define REPORT_FAILURE	0x2
+#define CMA_ALLOCATION	0x4
 
 void set_pageblock_migratetype(struct page *page, int migratetype);
 
 bool move_freepages_block_isolate(struct zone *zone, struct page *page);
 
 int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
-			     int migratetype, int flags, gfp_t gfp_flags);
+			     int flags, gfp_t gfp_flags);
 
 void undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn);
 
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 4265272faf4c..fe0b71e0f307 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1993,7 +1993,6 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
 
 	/* set above range as isolated */
 	ret = start_isolate_page_range(start_pfn, end_pfn,
-				       MIGRATE_MOVABLE,
 				       MEMORY_OFFLINE | REPORT_FAILURE,
 				       GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL);
 	if (ret) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4d06932ba69a..c60bb95d7e65 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6607,7 +6607,9 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end,
 	 * put back to page allocator so that buddy can use them.
 	 */
 
-	ret = start_isolate_page_range(start, end, migratetype, 0, gfp_mask);
+	ret = start_isolate_page_range(start, end,
+			migratetype == MIGRATE_CMA ? CMA_ALLOCATION : 0,
+			gfp_mask);
 	if (ret)
 		goto done;
 
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 4c65157d78ef..07c58b82db76 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -31,7 +31,7 @@
  *
  */
 static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long end_pfn,
-				int migratetype, int flags)
+				int flags)
 {
 	struct page *page = pfn_to_page(start_pfn);
 	struct zone *zone = page_zone(page);
@@ -46,7 +46,7 @@ static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long e
 		 * isolate CMA pageblocks even when they are not movable in fact
 		 * so consider them movable here.
 		 */
-		if (is_migrate_cma(migratetype))
+		if (flags & CMA_ALLOCATION)
 			return NULL;
 
 		return page;
@@ -144,7 +144,7 @@ static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long e
  * present in [start_pfn, end_pfn). The pageblock must intersect with
  * [start_pfn, end_pfn).
  */
-static int set_migratetype_isolate(struct page *page, int migratetype, int isol_flags,
+static int set_migratetype_isolate(struct page *page, int isol_flags,
 			unsigned long start_pfn, unsigned long end_pfn)
 {
 	struct zone *zone = page_zone(page);
@@ -179,7 +179,7 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_
 				  end_pfn);
 
 	unmovable = has_unmovable_pages(check_unmovable_start, check_unmovable_end,
-			migratetype, isol_flags);
+			isol_flags);
 	if (!unmovable) {
 		if (!move_freepages_block_isolate(zone, page)) {
 			spin_unlock_irqrestore(&zone->lock, flags);
@@ -290,7 +290,6 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages)
  * @isolate_before:	isolate the pageblock before the boundary_pfn
  * @skip_isolation:	the flag to skip the pageblock isolation in second
  *			isolate_single_pageblock()
- * @migratetype:	migrate type to set in error recovery.
  *
  * Free and in-use pages can be as big as MAX_PAGE_ORDER and contain more than one
  * pageblock. When not all pageblocks within a page are isolated at the same
@@ -306,8 +305,7 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages)
  * the in-use page then splitting the free page.
  */
 static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
-			gfp_t gfp_flags, bool isolate_before, bool skip_isolation,
-			int migratetype)
+			gfp_t gfp_flags, bool isolate_before, bool skip_isolation)
 {
 	unsigned long start_pfn;
 	unsigned long isolate_pageblock;
@@ -333,11 +331,9 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
 				      zone->zone_start_pfn);
 
 	if (skip_isolation) {
-		int mt __maybe_unused = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));
-
-		VM_BUG_ON(!is_migrate_isolate(mt));
+		VM_BUG_ON(!get_pageblock_isolate(pfn_to_page(isolate_pageblock)));
 	} else {
-		ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock), migratetype,
+		ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock),
 				flags, isolate_pageblock, isolate_pageblock + pageblock_nr_pages);
 
 		if (ret)
@@ -436,7 +432,6 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
  * start_isolate_page_range() - mark page range MIGRATE_ISOLATE
  * @start_pfn:		The first PFN of the range to be isolated.
  * @end_pfn:		The last PFN of the range to be isolated.
- * @migratetype:	Migrate type to set in error recovery.
  * @flags:		The following flags are allowed (they can be combined in
  *			a bit mask)
  *			MEMORY_OFFLINE - isolate to offline (!allocate) memory
@@ -478,7 +473,7 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
  * Return: 0 on success and -EBUSY if any part of range cannot be isolated.
  */
 int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
-			     int migratetype, int flags, gfp_t gfp_flags)
+			     int flags, gfp_t gfp_flags)
 {
 	unsigned long pfn;
 	struct page *page;
@@ -490,7 +485,7 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
 
 	/* isolate [isolate_start, isolate_start + pageblock_nr_pages) pageblock */
 	ret = isolate_single_pageblock(isolate_start, flags, gfp_flags, false,
-			skip_isolation, migratetype);
+			skip_isolation);
 	if (ret)
 		return ret;
 
@@ -499,7 +494,7 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
 
 	/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */
 	ret = isolate_single_pageblock(isolate_end, flags, gfp_flags, true,
-			skip_isolation, migratetype);
+			skip_isolation);
 	if (ret) {
 		unset_migratetype_isolate(pfn_to_page(isolate_start));
 		return ret;
@@ -510,7 +505,7 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
 	     pfn < isolate_end - pageblock_nr_pages;
 	     pfn += pageblock_nr_pages) {
 		page = __first_valid_page(pfn, pageblock_nr_pages);
-		if (page && set_migratetype_isolate(page, migratetype, flags,
+		if (page && set_migratetype_isolate(page, flags,
 					start_pfn, end_pfn)) {
 			undo_isolate_page_range(isolate_start, pfn);
 			unset_migratetype_isolate(
-- 
2.45.2