2 files changed, 53 insertions, 33 deletions

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 65f36d728714..8e76ddca0999 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -341,27 +341,26 @@ out:
 /*
  * ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab
  *
- * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how
- * many objects (pages) we have in total.
+ * 'nr_to_scan' is the number of objects to scan for freeing.
  *
  * 'gfp_mask' is the mask of the allocation that got us into this mess.
  *
- * Return value is the number of objects (pages) remaining, or -1 if we cannot
+ * Return value is the number of objects freed or -1 if we cannot
  * proceed without risk of deadlock (due to gfp_mask).
  *
  * We approximate LRU via least-recently-unpinned, jettisoning unpinned partial
  * chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan'
  * pages freed.
  */
-static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static unsigned long
+ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
 	struct ashmem_range *range, *next;
+	unsigned long freed = 0;
 
 	/* We might recurse into filesystem code, so bail out if necessary */
-	if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
-		return -1;
-	if (!sc->nr_to_scan)
-		return lru_count;
+	if (!(sc->gfp_mask & __GFP_FS))
+		return SHRINK_STOP;
 
 	mutex_lock(&ashmem_mutex);
 	list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) {
@@ -374,17 +373,32 @@ static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
 		range->purged = ASHMEM_WAS_PURGED;
 		lru_del(range);
 
-		sc->nr_to_scan -= range_size(range);
-		if (sc->nr_to_scan <= 0)
+		freed += range_size(range);
+		if (--sc->nr_to_scan <= 0)
 			break;
 	}
 	mutex_unlock(&ashmem_mutex);
+	return freed;
+}
 
+static unsigned long
+ashmem_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	/*
+	 * note that lru_count is count of pages on the lru, not a count of
+	 * objects on the list. This means the scan function needs to return the
+	 * number of pages freed, not the number of objects scanned.
+	 */
 	return lru_count;
 }
 
 static struct shrinker ashmem_shrinker = {
-	.shrink = ashmem_shrink,
+	.count_objects = ashmem_shrink_count,
+	.scan_objects = ashmem_shrink_scan,
+	/*
+	 * XXX (dchinner): I wish people would comment on why they need on
+	 * significant changes to the default value here
+	 */
 	.seeks = DEFAULT_SEEKS * 4,
 };
 
@@ -690,14 +704,11 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (capable(CAP_SYS_ADMIN)) {
 			struct shrink_control sc = {
 				.gfp_mask = GFP_KERNEL,
-				.nr_to_scan = 0,
+				.nr_to_scan = LONG_MAX,
 			};
 
 			nodes_setall(sc.nodes_to_scan);
-
-			ret = ashmem_shrink(&ashmem_shrinker, &sc);
-			sc.nr_to_scan = ret;
-			ashmem_shrink(&ashmem_shrinker, &sc);
+			ashmem_shrink_scan(&ashmem_shrinker, &sc);
 		}
 		break;
 	}
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index fe74494868ef..6f094b37f1f1 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -66,11 +66,20 @@ static unsigned long lowmem_deathpending_timeout;
 			pr_info(x);			\
 	} while (0)
 
-static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static unsigned long lowmem_count(struct shrinker *s,
+				  struct shrink_control *sc)
+{
+	return global_page_state(NR_ACTIVE_ANON) +
+		global_page_state(NR_ACTIVE_FILE) +
+		global_page_state(NR_INACTIVE_ANON) +
+		global_page_state(NR_INACTIVE_FILE);
+}
+
+static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
 {
 	struct task_struct *tsk;
 	struct task_struct *selected = NULL;
-	int rem = 0;
+	unsigned long rem = 0;
 	int tasksize;
 	int i;
 	short min_score_adj = OOM_SCORE_ADJ_MAX + 1;
@@ -92,19 +101,17 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
 			break;
 		}
 	}
-	if (sc->nr_to_scan > 0)
-		lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
-				sc->nr_to_scan, sc->gfp_mask, other_free,
-				other_file, min_score_adj);
-	rem = global_page_state(NR_ACTIVE_ANON) +
-		global_page_state(NR_ACTIVE_FILE) +
-		global_page_state(NR_INACTIVE_ANON) +
-		global_page_state(NR_INACTIVE_FILE);
-	if (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
-		lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
-			     sc->nr_to_scan, sc->gfp_mask, rem);
-		return rem;
+
+	lowmem_print(3, "lowmem_scan %lu, %x, ofree %d %d, ma %hd\n",
+			sc->nr_to_scan, sc->gfp_mask, other_free,
+			other_file, min_score_adj);
+
+	if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
+		lowmem_print(5, "lowmem_scan %lu, %x, return 0\n",
+			     sc->nr_to_scan, sc->gfp_mask);
+		return 0;
 	}
+
 	selected_oom_score_adj = min_score_adj;
 
 	rcu_read_lock();
@@ -154,16 +161,18 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
 		lowmem_deathpending_timeout = jiffies + HZ;
 		send_sig(SIGKILL, selected, 0);
 		set_tsk_thread_flag(selected, TIF_MEMDIE);
-		rem -= selected_tasksize;
+		rem += selected_tasksize;
 	}
-	lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
+
+	lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n",
 		     sc->nr_to_scan, sc->gfp_mask, rem);
 	rcu_read_unlock();
 	return rem;
 }
 
 static struct shrinker lowmem_shrinker = {
-	.shrink = lowmem_shrink,
+	.scan_objects = lowmem_scan,
+	.count_objects = lowmem_count,
 	.seeks = DEFAULT_SEEKS * 16
 };