we have isolated mapped page and re-add it into LRU's head. It's
unnecessary CPU overhead and makes LRU churning.
Of course, when we isolate the page, the page might be mapped but when we
try to migrate the page, the page would be not mapped. So it could be
migrated. But race is rare and although it happens, it's no big deal.
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
#define ISOLATE_ACTIVE ((__force fmode_t)0x2)
/* Isolate clean file */
#define ISOLATE_CLEAN ((__force fmode_t)0x4)
#define ISOLATE_ACTIVE ((__force fmode_t)0x2)
/* Isolate clean file */
#define ISOLATE_CLEAN ((__force fmode_t)0x4)
+/* Isolate unmapped file */
+#define ISOLATE_UNMAPPED ((__force fmode_t)0x8)
+
/* LRU Isolation modes. */
typedef unsigned __bitwise__ isolate_mode_t;
/* LRU Isolation modes. */
typedef unsigned __bitwise__ isolate_mode_t;
if ((mode & ISOLATE_CLEAN) && (PageDirty(page) || PageWriteback(page)))
return ret;
if ((mode & ISOLATE_CLEAN) && (PageDirty(page) || PageWriteback(page)))
return ret;
+ if ((mode & ISOLATE_UNMAPPED) && page_mapped(page))
+ return ret;
+
if (likely(get_page_unless_zero(page))) {
/*
* Be careful not to clear PageLRU until after we're
if (likely(get_page_unless_zero(page))) {
/*
* Be careful not to clear PageLRU until after we're
reclaim_mode |= ISOLATE_ACTIVE;
lru_add_drain();
reclaim_mode |= ISOLATE_ACTIVE;
lru_add_drain();
+
+ if (!sc->may_unmap)
+ reclaim_mode |= ISOLATE_UNMAPPED;
+ if (!sc->may_writepage)
+ reclaim_mode |= ISOLATE_CLEAN;
+
spin_lock_irq(&zone->lru_lock);
if (scanning_global_lru(sc)) {
spin_lock_irq(&zone->lru_lock);
if (scanning_global_lru(sc)) {
struct page *page;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
unsigned long nr_rotated = 0;
struct page *page;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
unsigned long nr_rotated = 0;
+ isolate_mode_t reclaim_mode = ISOLATE_ACTIVE;
+
+ if (!sc->may_unmap)
+ reclaim_mode |= ISOLATE_UNMAPPED;
+ if (!sc->may_writepage)
+ reclaim_mode |= ISOLATE_CLEAN;
+
spin_lock_irq(&zone->lru_lock);
if (scanning_global_lru(sc)) {
nr_taken = isolate_pages_global(nr_pages, &l_hold,
&pgscanned, sc->order,
spin_lock_irq(&zone->lru_lock);
if (scanning_global_lru(sc)) {
nr_taken = isolate_pages_global(nr_pages, &l_hold,
&pgscanned, sc->order,
1, file);
zone->pages_scanned += pgscanned;
} else {
nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
&pgscanned, sc->order,
1, file);
zone->pages_scanned += pgscanned;
} else {
nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
&pgscanned, sc->order,
sc->mem_cgroup, 1, file);
/*
* mem_cgroup_isolate_pages() keeps track of
sc->mem_cgroup, 1, file);
/*
* mem_cgroup_isolate_pages() keeps track of