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-rw-r--r--mm/zsmalloc.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b7b4a5612ec7..27b9661c8fa6 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -246,6 +246,14 @@ struct zs_pool {
atomic_long_t pages_allocated;
struct zs_pool_stats stats;
+
+ /* Compact classes */
+ struct shrinker shrinker;
+ /*
+ * To signify that register_shrinker() was successful
+ * and unregister_shrinker() will not Oops.
+ */
+ bool shrinker_enabled;
#ifdef CONFIG_ZSMALLOC_STAT
struct dentry *stat_dentry;
#endif
@@ -1778,6 +1786,69 @@ void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats)
}
EXPORT_SYMBOL_GPL(zs_pool_stats);
+static unsigned long zs_shrinker_scan(struct shrinker *shrinker,
+ struct shrink_control *sc)
+{
+ unsigned long pages_freed;
+ struct zs_pool *pool = container_of(shrinker, struct zs_pool,
+ shrinker);
+
+ pages_freed = pool->stats.pages_compacted;
+ /*
+ * Compact classes and calculate compaction delta.
+ * Can run concurrently with a manually triggered
+ * (by user) compaction.
+ */
+ pages_freed = zs_compact(pool) - pages_freed;
+
+ return pages_freed ? pages_freed : SHRINK_STOP;
+}
+
+static unsigned long zs_shrinker_count(struct shrinker *shrinker,
+ struct shrink_control *sc)
+{
+ int i;
+ struct size_class *class;
+ unsigned long pages_to_free = 0;
+ struct zs_pool *pool = container_of(shrinker, struct zs_pool,
+ shrinker);
+
+ if (!pool->shrinker_enabled)
+ return 0;
+
+ for (i = zs_size_classes - 1; i >= 0; i--) {
+ class = pool->size_class[i];
+ if (!class)
+ continue;
+ if (class->index != i)
+ continue;
+
+ spin_lock(&class->lock);
+ pages_to_free += zs_can_compact(class);
+ spin_unlock(&class->lock);
+ }
+
+ return pages_to_free;
+}
+
+static void zs_unregister_shrinker(struct zs_pool *pool)
+{
+ if (pool->shrinker_enabled) {
+ unregister_shrinker(&pool->shrinker);
+ pool->shrinker_enabled = false;
+ }
+}
+
+static int zs_register_shrinker(struct zs_pool *pool)
+{
+ pool->shrinker.scan_objects = zs_shrinker_scan;
+ pool->shrinker.count_objects = zs_shrinker_count;
+ pool->shrinker.batch = 0;
+ pool->shrinker.seeks = DEFAULT_SEEKS;
+
+ return register_shrinker(&pool->shrinker);
+}
+
/**
* zs_create_pool - Creates an allocation pool to work from.
* @flags: allocation flags used to allocate pool metadata
@@ -1863,6 +1934,12 @@ struct zs_pool *zs_create_pool(char *name, gfp_t flags)
if (zs_pool_stat_create(name, pool))
goto err;
+ /*
+ * Not critical, we still can use the pool
+ * and user can trigger compaction manually.
+ */
+ if (zs_register_shrinker(pool) == 0)
+ pool->shrinker_enabled = true;
return pool;
err:
@@ -1875,6 +1952,7 @@ void zs_destroy_pool(struct zs_pool *pool)
{
int i;
+ zs_unregister_shrinker(pool);
zs_pool_stat_destroy(pool);
for (i = 0; i < zs_size_classes; i++) {