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>
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index c255fcc..be76429 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -25,13 +25,13 @@
#define trace_reclaim_flags(page, sync) ( \
(page_is_file_cache(page) ? RECLAIM_WB_FILE : RECLAIM_WB_ANON) | \
- (sync == LUMPY_MODE_SYNC ? RECLAIM_WB_SYNC : RECLAIM_WB_ASYNC) \
+ (sync & LUMPY_MODE_SYNC ? RECLAIM_WB_SYNC : RECLAIM_WB_ASYNC) \
)
#define trace_shrink_flags(file, sync) ( \
- (sync == LUMPY_MODE_SYNC ? RECLAIM_WB_MIXED : \
+ (sync & LUMPY_MODE_SYNC ? RECLAIM_WB_MIXED : \
(file ? RECLAIM_WB_FILE : RECLAIM_WB_ANON)) | \
- (sync == LUMPY_MODE_SYNC ? RECLAIM_WB_SYNC : RECLAIM_WB_ASYNC) \
+ (sync & LUMPY_MODE_SYNC ? RECLAIM_WB_SYNC : RECLAIM_WB_ASYNC) \
)
TRACE_EVENT(mm_vmscan_kswapd_sleep,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index cacdf66..3464312 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 @@
* 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 @@
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 @@
* 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 @@
* 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 @@
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 @@
* 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 @@
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 @@
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 @@
} 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);