mm, thp: fix mlock statistics

NR_MLOCK is only accounted in single page units: there's no logic to handle transparent hugepages. This patch checks the appropriate number of pages to adjust the statistics by so that the correct amount of memory is reflected. Currently: $ grep Mlocked /proc/meminfo Mlocked: 19636 kB #define MAP_SIZE (4 << 30) /* 4GB */ void *ptr = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); mlock(ptr, MAP_SIZE); $ grep Mlocked /proc/meminfo Mlocked: 29844 kB munlock(ptr, MAP_SIZE); $ grep Mlocked /proc/meminfo Mlocked: 19636 kB And with this patch: $ grep Mlock /proc/meminfo Mlocked: 19636 kB mlock(ptr, MAP_SIZE); $ grep Mlock /proc/meminfo Mlocked: 4213664 kB munlock(ptr, MAP_SIZE); $ grep Mlock /proc/meminfo Mlocked: 19636 kB Signed-off-by: David Rientjes <[email protected]> Reported-by: Hugh Dickens <[email protected]> Acked-by: Hugh Dickins <[email protected]> Reviewed-by: Andrea Arcangeli <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Cc: Johannes Weiner <[email protected]> Reviewed-by: Michel Lespinasse <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
powerwareeasyman · Oct 9, 2012 · 8449d21 · 8449d21
1 parent b676b29
commit 8449d21
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/mm/internal.h b/mm/internal.h
@@ -180,7 +180,8 @@ static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
 		return 0;
 
 	if (!TestSetPageMlocked(page)) {
-		inc_zone_page_state(page, NR_MLOCK);
+		mod_zone_page_state(page_zone(page), NR_MLOCK,
+				    hpage_nr_pages(page));
 		count_vm_event(UNEVICTABLE_PGMLOCKED);
 	}
 	return 1;

diff --git a/mm/mlock.c b/mm/mlock.c
@@ -56,7 +56,8 @@ void clear_page_mlock(struct page *page)
 	if (!TestClearPageMlocked(page))
 		return;
 
-	dec_zone_page_state(page, NR_MLOCK);
+	mod_zone_page_state(page_zone(page), NR_MLOCK,
+			    -hpage_nr_pages(page));
 	count_vm_event(UNEVICTABLE_PGCLEARED);
 	if (!isolate_lru_page(page)) {
 		putback_lru_page(page);
@@ -78,7 +79,8 @@ void mlock_vma_page(struct page *page)
 	BUG_ON(!PageLocked(page));
 
 	if (!TestSetPageMlocked(page)) {
-		inc_zone_page_state(page, NR_MLOCK);
+		mod_zone_page_state(page_zone(page), NR_MLOCK,
+				    hpage_nr_pages(page));
 		count_vm_event(UNEVICTABLE_PGMLOCKED);
 		if (!isolate_lru_page(page))
 			putback_lru_page(page);
@@ -105,7 +107,8 @@ void munlock_vma_page(struct page *page)
 	BUG_ON(!PageLocked(page));
 
 	if (TestClearPageMlocked(page)) {
-		dec_zone_page_state(page, NR_MLOCK);
+		mod_zone_page_state(page_zone(page), NR_MLOCK,
+				    -hpage_nr_pages(page));
 		if (!isolate_lru_page(page)) {
 			int ret = SWAP_AGAIN;