From: Xishi Qiu <qiuxishi@huawei.com>
Date: Fri, 7 Oct 2016 23:58:09 +0000 (-0700)
Subject: mm: fix set pageblock migratetype in deferred struct page init
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e780149bcd4be171421535db0514fa9ff556cb87;p=linux-beck.git

mm: fix set pageblock migratetype in deferred struct page init

On x86_64 MAX_ORDER_NR_PAGES is usually 4M, and a pageblock is usually
2M, so we only set one pageblock's migratetype in deferred_free_range()
if pfn is aligned to MAX_ORDER_NR_PAGES.  That means it causes
uninitialized migratetype blocks, you can see from "cat
/proc/pagetypeinfo", almost half blocks are Unmovable.

Also we missed freeing the last block in deferred_init_memmap(), it
causes memory leak.

Fixes: ac5d2539b238 ("mm: meminit: reduce number of times pageblocks are set during struct page init")
Link: http://lkml.kernel.org/r/57A3260F.4050709@huawei.com
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 26246fdf45b5..0c34633720c0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1393,15 +1393,18 @@ static void __init deferred_free_range(struct page *page,
 		return;
 
 	/* Free a large naturally-aligned chunk if possible */
-	if (nr_pages == MAX_ORDER_NR_PAGES &&
-	    (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
+	if (nr_pages == pageblock_nr_pages &&
+	    (pfn & (pageblock_nr_pages - 1)) == 0) {
 		set_pageblock_migratetype(page, MIGRATE_MOVABLE);
-		__free_pages_boot_core(page, MAX_ORDER-1);
+		__free_pages_boot_core(page, pageblock_order);
 		return;
 	}
 
-	for (i = 0; i < nr_pages; i++, page++)
+	for (i = 0; i < nr_pages; i++, page++, pfn++) {
+		if ((pfn & (pageblock_nr_pages - 1)) == 0)
+			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
 		__free_pages_boot_core(page, 0);
+	}
 }
 
 /* Completion tracking for deferred_init_memmap() threads */
@@ -1469,9 +1472,9 @@ static int __init deferred_init_memmap(void *data)
 
 			/*
 			 * Ensure pfn_valid is checked every
-			 * MAX_ORDER_NR_PAGES for memory holes
+			 * pageblock_nr_pages for memory holes
 			 */
-			if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+			if ((pfn & (pageblock_nr_pages - 1)) == 0) {
 				if (!pfn_valid(pfn)) {
 					page = NULL;
 					goto free_range;
@@ -1484,7 +1487,7 @@ static int __init deferred_init_memmap(void *data)
 			}
 
 			/* Minimise pfn page lookups and scheduler checks */
-			if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
+			if (page && (pfn & (pageblock_nr_pages - 1)) != 0) {
 				page++;
 			} else {
 				nr_pages += nr_to_free;
@@ -1520,6 +1523,9 @@ free_range:
 			free_base_page = NULL;
 			free_base_pfn = nr_to_free = 0;
 		}
+		/* Free the last block of pages to allocator */
+		nr_pages += nr_to_free;
+		deferred_free_range(free_base_page, free_base_pfn, nr_to_free);
 
 		first_init_pfn = max(end_pfn, first_init_pfn);
 	}