[066/156] mm/page_alloc: drop stale pageblock comment in memmap_init_zone*()

Commit Message

Andrew Morton Oct. 16, 2020, 2:45 a.m. UTC

From: David Hildenbrand <[e-mail]>
Subject: mm/page_alloc: drop stale pageblock comment in memmap_init_zone*()

Commit ac5d2539b238 ("mm: meminit: reduce number of times pageblocks are
set during struct page init") moved the actual zone range check, leaving
only the alignment check for pageblocks.

Let's drop the stale comment and make the pageblock check easier to read.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: David Hildenbrand <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
Reviewed-by: Oscar Salvador <[e-mail]>
Cc: Wei Yang <[e-mail]>
Cc: Baoquan He <[e-mail]>
Cc: Pankaj Gupta <[e-mail]>
Cc: Mel Gorman <[e-mail]>
Cc: Charan Teja Reddy <[e-mail]>
Cc: Dan Williams <[e-mail]>
Cc: Fenghua Yu <[e-mail]>
Cc: Logan Gunthorpe <[e-mail]>
Cc: "Matthew Wilcox (Oracle)" <[e-mail]>
Cc: Mel Gorman <[e-mail]>
Cc: Michel Lespinasse <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Tony Luck <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/page_alloc.c |   14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

Patch

--- a/mm/page_alloc.c~mm-page_alloc-drop-stale-pageblock-comment-in-memmap_init_zone
+++ a/mm/page_alloc.c
@@ -6042,13 +6042,8 @@  void __meminit memmap_init_zone(unsigned
 		 * to reserve their blocks rather than leaking throughout
 		 * the address space during boot when many long-lived
 		 * kernel allocations are made.
-		 *
-		 * bitmap is created for zone's valid pfn range. but memmap
-		 * can be created for invalid pages (for alignment)
-		 * check here not to call set_pageblock_migratetype() against
-		 * pfn out of zone.
 		 */
-		if (!(pfn & (pageblock_nr_pages - 1))) {
+		if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
 			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
 			cond_resched();
 		}
@@ -6111,15 +6106,10 @@  void __ref memmap_init_zone_device(struc
 		 * the address space during boot when many long-lived
 		 * kernel allocations are made.
 		 *
-		 * bitmap is created for zone's valid pfn range. but memmap
-		 * can be created for invalid pages (for alignment)
-		 * check here not to call set_pageblock_migratetype() against
-		 * pfn out of zone.
-		 *
 		 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
 		 * because this is done early in section_activate()
 		 */
-		if (!(pfn & (pageblock_nr_pages - 1))) {
+		if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
 			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
 			cond_resched();
 		}