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authorMel Gorman <mel@csn.ul.ie>2011-01-13 15:45:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 17:32:33 -0800
commitee64fc9354e515a79c7232cfde65c88ec627308b (patch)
treefb5fb6c0045ff5467ed5870d5f64806784deba2d /mm/vmscan.c
parentb7aba6984dc048503b69c2a885098cdd430832bf (diff)
mm: vmscan: convert lumpy_mode into a bitmask
Currently lumpy_mode is an enum and determines if lumpy reclaim is off, syncronous or asyncronous. In preparation for using compaction instead of lumpy reclaim, this patch converts the flags into a bitmap. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c46
1 files changed, 28 insertions, 18 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index cacdf668497..3464312bde0 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -51,11 +51,20 @@
#define CREATE_TRACE_POINTS
#include <trace/events/vmscan.h>
-enum lumpy_mode {
- LUMPY_MODE_NONE,
- LUMPY_MODE_ASYNC,
- LUMPY_MODE_SYNC,
-};
+/*
+ * lumpy_mode determines how the inactive list is shrunk
+ * LUMPY_MODE_SINGLE: Reclaim only order-0 pages
+ * LUMPY_MODE_ASYNC: Do not block
+ * LUMPY_MODE_SYNC: Allow blocking e.g. call wait_on_page_writeback
+ * LUMPY_MODE_CONTIGRECLAIM: For high-order allocations, take a reference
+ * page from the LRU and reclaim all pages within a
+ * naturally aligned range
+ */
+typedef unsigned __bitwise__ lumpy_mode;
+#define LUMPY_MODE_SINGLE ((__force lumpy_mode)0x01u)
+#define LUMPY_MODE_ASYNC ((__force lumpy_mode)0x02u)
+#define LUMPY_MODE_SYNC ((__force lumpy_mode)0x04u)
+#define LUMPY_MODE_CONTIGRECLAIM ((__force lumpy_mode)0x08u)
struct scan_control {
/* Incremented by the number of inactive pages that were scanned */
@@ -88,7 +97,7 @@ struct scan_control {
* Intend to reclaim enough continuous memory rather than reclaim
* enough amount of memory. i.e, mode for high order allocation.
*/
- enum lumpy_mode lumpy_reclaim_mode;
+ lumpy_mode lumpy_reclaim_mode;
/* Which cgroup do we reclaim from */
struct mem_cgroup *mem_cgroup;
@@ -274,13 +283,13 @@ unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc,
bool sync)
{
- enum lumpy_mode mode = sync ? LUMPY_MODE_SYNC : LUMPY_MODE_ASYNC;
+ lumpy_mode syncmode = sync ? LUMPY_MODE_SYNC : LUMPY_MODE_ASYNC;
/*
* Some reclaim have alredy been failed. No worth to try synchronous
* lumpy reclaim.
*/
- if (sync && sc->lumpy_reclaim_mode == LUMPY_MODE_NONE)
+ if (sync && sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE)
return;
/*
@@ -288,17 +297,18 @@ static void set_lumpy_reclaim_mode(int priority, struct scan_control *sc,
* trouble getting a small set of contiguous pages, we
* will reclaim both active and inactive pages.
*/
+ sc->lumpy_reclaim_mode = LUMPY_MODE_CONTIGRECLAIM;
if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
- sc->lumpy_reclaim_mode = mode;
+ sc->lumpy_reclaim_mode |= syncmode;
else if (sc->order && priority < DEF_PRIORITY - 2)
- sc->lumpy_reclaim_mode = mode;
+ sc->lumpy_reclaim_mode |= syncmode;
else
- sc->lumpy_reclaim_mode = LUMPY_MODE_NONE;
+ sc->lumpy_reclaim_mode = LUMPY_MODE_SINGLE | LUMPY_MODE_ASYNC;
}
static void disable_lumpy_reclaim_mode(struct scan_control *sc)
{
- sc->lumpy_reclaim_mode = LUMPY_MODE_NONE;
+ sc->lumpy_reclaim_mode = LUMPY_MODE_SINGLE | LUMPY_MODE_ASYNC;
}
static inline int is_page_cache_freeable(struct page *page)
@@ -429,7 +439,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
* first attempt to free a range of pages fails.
*/
if (PageWriteback(page) &&
- sc->lumpy_reclaim_mode == LUMPY_MODE_SYNC)
+ (sc->lumpy_reclaim_mode & LUMPY_MODE_SYNC))
wait_on_page_writeback(page);
if (!PageWriteback(page)) {
@@ -622,7 +632,7 @@ static enum page_references page_check_references(struct page *page,
referenced_page = TestClearPageReferenced(page);
/* Lumpy reclaim - ignore references */
- if (sc->lumpy_reclaim_mode != LUMPY_MODE_NONE)
+ if (sc->lumpy_reclaim_mode & LUMPY_MODE_CONTIGRECLAIM)
return PAGEREF_RECLAIM;
/*
@@ -739,7 +749,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
* for any page for which writeback has already
* started.
*/
- if (sc->lumpy_reclaim_mode == LUMPY_MODE_SYNC &&
+ if ((sc->lumpy_reclaim_mode & LUMPY_MODE_SYNC) &&
may_enter_fs)
wait_on_page_writeback(page);
else {
@@ -1324,7 +1334,7 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
return false;
/* Only stall on lumpy reclaim */
- if (sc->lumpy_reclaim_mode == LUMPY_MODE_NONE)
+ if (sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE)
return false;
/* If we have relaimed everything on the isolated list, no stall */
@@ -1375,7 +1385,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
if (scanning_global_lru(sc)) {
nr_taken = isolate_pages_global(nr_to_scan,
&page_list, &nr_scanned, sc->order,
- sc->lumpy_reclaim_mode == LUMPY_MODE_NONE ?
+ sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE ?
ISOLATE_INACTIVE : ISOLATE_BOTH,
zone, 0, file);
zone->pages_scanned += nr_scanned;
@@ -1388,7 +1398,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
} else {
nr_taken = mem_cgroup_isolate_pages(nr_to_scan,
&page_list, &nr_scanned, sc->order,
- sc->lumpy_reclaim_mode == LUMPY_MODE_NONE ?
+ sc->lumpy_reclaim_mode & LUMPY_MODE_SINGLE ?
ISOLATE_INACTIVE : ISOLATE_BOTH,
zone, sc->mem_cgroup,
0, file);