Merge "mm: zcache: shrink zcache on memory pressure" (a515f83f) · Commits · e / devices / android_kernel_xiaomi_markw

mm/zcache.c

+68 −0

Original line number	Diff line number	Diff line
		@@ -69,6 +69,9 @@ static u64 zcache_evict_zpages;
		static u64 zcache_evict_filepages;
		static u64 zcache_inactive_pages_refused;
		static u64 zcache_reclaim_fail;
		static u64 zcache_pool_shrink;
		static u64 zcache_pool_shrink_fail;
		static u64 zcache_pool_shrink_pages;
		static atomic_t zcache_stored_pages = ATOMIC_INIT(0);

		#define GFP_ZCACHE \
		@@ -154,6 +157,64 @@ static void zcache_rbnode_cache_destroy(void)
		kmem_cache_destroy(zcache_rbnode_cache);
		}

		static unsigned long zcache_count(struct shrinker *s,
		struct shrink_control *sc)
		{
		unsigned long active_file;
		long file_gap;

		active_file = global_page_state(NR_ACTIVE_FILE);
		file_gap = zcache_pool_pages - active_file;
		if (file_gap < 0)
		file_gap = 0;
		return file_gap;
		}

		static unsigned long zcache_scan(struct shrinker s, struct shrink_control sc)
		{
		unsigned long active_file;
		long file_gap;
		unsigned long freed = 0;
		static bool running;
		struct zcache_pool *zpool = zcache.pools[0];

		if (running)
		goto end;

		running = true;
		active_file = global_page_state(NR_ACTIVE_FILE);

		/*
		* file_gap == 0 means that the number of pages
		* stored by zcache is around twice as many as the
		* number of active file pages.
		*/
		file_gap = zcache_pool_pages - active_file;
		if (file_gap < 0)
		file_gap = 0;
		else
		zcache_pool_shrink++;
		while (file_gap-- > 0) {
		if (zbud_reclaim_page(zpool->pool, 8)) {
		zcache_pool_shrink_fail++;
		break;
		}
		freed++;
		}

		zcache_pool_shrink_pages += freed;
		zcache_pool_pages = zbud_get_pool_size(zpool->pool);
		running = false;
		end:
		return freed;
		}

		static struct shrinker zcache_shrinker = {
		.scan_objects = zcache_scan,
		.count_objects = zcache_count,
		.seeks = DEFAULT_SEEKS * 16
		};

		/*
		* Compression functions
		* (Below functions are copyed from zswap!)
		@@ -895,6 +956,12 @@ static int __init zcache_debugfs_init(void)
		&zcache_reclaim_fail);
		debugfs_create_u64("inactive_pages_refused", S_IRUGO,
		zcache_debugfs_root, &zcache_inactive_pages_refused);
		debugfs_create_u64("pool_shrink_count", S_IRUGO,
		zcache_debugfs_root, &zcache_pool_shrink);
		debugfs_create_u64("pool_shrink_fail", S_IRUGO,
		zcache_debugfs_root, &zcache_pool_shrink_fail);
		debugfs_create_u64("pool_shrink_pages", S_IRUGO,
		zcache_debugfs_root, &zcache_pool_shrink_pages);
		return 0;
		}

		@@ -940,6 +1007,7 @@ static int __init init_zcache(void)

		if (zcache_debugfs_init())
		pr_warn("debugfs initialization failed\n");
		register_shrinker(&zcache_shrinker);
		return 0;
		pcpufail:
		zcache_comp_exit();