Merge "mm: zcache: clear zcache when low on file pages" (2ed7ea55) · Commits · e / devices / android_kernel_xiaomi_markw

mm/zcache.c

+28 −5

Original line number	Diff line number	Diff line
		@@ -58,6 +58,8 @@ module_param_named(compressor, zcache_compressor, charp, 0);
		static unsigned int zcache_max_pool_percent = 10;
		module_param_named(max_pool_percent, zcache_max_pool_percent, uint, 0644);

		static unsigned int zcache_clear_percent = 4;
		module_param_named(clear_percent, zcache_clear_percent, uint, 0644);
		/*
		* zcache statistics
		*/
		@@ -188,36 +190,53 @@ static unsigned long zcache_count(struct shrinker *s,
		static unsigned long zcache_scan(struct shrinker s, struct shrink_control sc)
		{
		unsigned long active_file;
		unsigned long file;
		long file_gap;
		unsigned long freed = 0;
		unsigned long pool;
		static bool running;
		int i = 0;
		int retries;

		if (running)
		goto end;

		running = true;
		active_file = global_page_state(NR_ACTIVE_FILE);
		file = global_page_state(NR_FILE_PAGES);
		pool = zcache_pages();

		file_gap = pool - file;

		if ((file_gap >= 0) &&
		(totalram_pages * zcache_clear_percent / 100 > file)) {
		file_gap = pool;
		zcache_pool_shrink++;
		goto reclaim;
		}

		/*
		* 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_pages() - active_file;
		file_gap = pool - active_file;
		if (file_gap < 0)
		file_gap = 0;
		else
		zcache_pool_shrink++;

		while (file_gap > 0) {
		reclaim:
		retries = file_gap;
		while ((file_gap > 0) && retries) {
		struct zcache_pool *zpool =
		zcache.pools[i++ % MAX_ZCACHE_POOLS];
		if (!zpool \|\| !zpool->size)
		continue;
		if (zbud_reclaim_page(zpool->pool, 8)) {
		zcache_pool_shrink_fail++;
		break;
		retries--;
		continue;
		}
		freed++;
		file_gap--;
		@@ -379,8 +398,12 @@ cleanup:
		*/
		static bool zcache_is_full(void)
		{
		return totalram_pages * zcache_max_pool_percent / 100 <
		zcache_pages();
		long file = global_page_state(NR_FILE_PAGES);

		return ((totalram_pages * zcache_max_pool_percent / 100 <
		zcache_pages()) \|\|
		(totalram_pages * zcache_clear_percent / 100 >
		file));
		}

		/*