From a0c5e813f087dffc0d9b173d2e7d3328b1482fd5 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hughd@google.com>
Date: Mon, 8 Oct 2012 16:33:21 -0700
Subject: [PATCH] mm: remove free_page_mlock
We should not be seeing non-0 unevictable_pgs_mlockfreed any longer. So
remove free_page_mlock() from the page freeing paths: __PG_MLOCKED is
already in PAGE_FLAGS_CHECK_AT_FREE, so free_pages_check() will now be
checking it, reporting "BUG: Bad page state" if it's ever found set.
Comment UNEVICTABLE_MLOCKFREED and unevictable_pgs_mlockfreed always 0.
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/vm_event_item.h | 2 +-
mm/page_alloc.c | 17 -----------------
mm/vmstat.c | 2 +-
3 files changed, 2 insertions(+), 19 deletions(-)
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 57f7b1091511b..ede4ddd466959 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -52,7 +52,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
UNEVICTABLE_PGMUNLOCKED,
UNEVICTABLE_PGCLEARED, /* on COW, page truncate */
UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */
- UNEVICTABLE_MLOCKFREED,
+ UNEVICTABLE_MLOCKFREED, /* no longer useful: always zero */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
THP_FAULT_ALLOC,
THP_FAULT_FALLBACK,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 00750bc08a3ad..dbb53866c3aa9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -598,17 +598,6 @@ static inline void __free_one_page(struct page *page,
zone->free_area[order].nr_free++;
}
-/*
- * free_page_mlock() -- clean up attempts to free and mlocked() page.
- * Page should not be on lru, so no need to fix that up.
- * free_pages_check() will verify...
- */
-static inline void free_page_mlock(struct page *page)
-{
- __dec_zone_page_state(page, NR_MLOCK);
- __count_vm_event(UNEVICTABLE_MLOCKFREED);
-}
-
static inline int free_pages_check(struct page *page)
{
if (unlikely(page_mapcount(page) |
@@ -728,15 +717,12 @@ static bool free_pages_prepare(struct page *page, unsigned int order)
static void __free_pages_ok(struct page *page, unsigned int order)
{
unsigned long flags;
- int wasMlocked = __TestClearPageMlocked(page);
int migratetype;
if (!free_pages_prepare(page, order))
return;
local_irq_save(flags);
- if (unlikely(wasMlocked))
- free_page_mlock(page);
__count_vm_events(PGFREE, 1 << order);
migratetype = get_pageblock_migratetype(page);
set_freepage_migratetype(page, migratetype);
@@ -1310,7 +1296,6 @@ void free_hot_cold_page(struct page *page, int cold)
struct per_cpu_pages *pcp;
unsigned long flags;
int migratetype;
- int wasMlocked = __TestClearPageMlocked(page);
if (!free_pages_prepare(page, 0))
return;
@@ -1318,8 +1303,6 @@ void free_hot_cold_page(struct page *page, int cold)
migratetype = get_pageblock_migratetype(page);
set_freepage_migratetype(page, migratetype);
local_irq_save(flags);
- if (unlikely(wasMlocked))
- free_page_mlock(page);
__count_vm_event(PGFREE);
/*
diff --git a/mm/vmstat.c b/mm/vmstat.c
index acbd85c983e63..05e3a99137444 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -782,7 +782,7 @@ const char * const vmstat_text[] = {
"unevictable_pgs_munlocked",
"unevictable_pgs_cleared",
"unevictable_pgs_stranded",
- "unevictable_pgs_mlockfreed",
+ "unevictable_pgs_mlockfreed", /* no longer useful: always zero */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
"thp_fault_alloc",
--
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