Commit 699bb9e8 authored by Liu Shixin's avatar Liu Shixin Committed by Ma Wupeng
Browse files

mm/zswap: delay the initializaton of zswap until the first enablement 

hulk inclusion
category: performance
bugzilla: 187468, https://gitee.com/openeuler/kernel/issues/I61HSG



--------------------------------

The zswap initialization consumes some memory. If we don't use zswap,
there's no need to initial it. So delay the initializaton of zswap until
the first enablement.

Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
parent 3286455e

mm/zswap.c

+37 −7
Original line number Diff line number Diff line
@@ -79,6 +79,8 @@ static bool zswap_pool_reached_full; 


#define ZSWAP_PARAM_UNSET ""



static int zswap_setup(void);



/* Enable/disable zswap */

static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON);

static int zswap_enabled_param_set(const char *,
@@ -209,6 +211,8 @@ static atomic_t zswap_pools_count = ATOMIC_INIT(0); 


/* init state */

static int zswap_init_state;

/* used to ensure the integrity of initialization */

static DEFINE_MUTEX(zswap_init_lock);



/* init completed, but couldn't create the initial pool */

static bool zswap_has_pool;
@@ -767,11 +771,17 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, 
	if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool)

		return 0;



	/* if this is load-time (pre-init) param setting,

	/*

	 * if zswap has not been initialized,

	 * don't create a pool; that's done during init.

	 */

	if (zswap_init_state == ZSWAP_UNINIT)

		return param_set_charp(s, kp);

	mutex_lock(&zswap_init_lock);

	if (zswap_init_state == ZSWAP_UNINIT) {

		ret = param_set_charp(s, kp);

		mutex_unlock(&zswap_init_lock);

		return ret;

	}

	mutex_unlock(&zswap_init_lock);



	if (!type) {

		if (!zpool_has_pool(s)) {
@@ -861,6 +871,14 @@ static int zswap_zpool_param_set(const char *val, 
static int zswap_enabled_param_set(const char *val,

				   const struct kernel_param *kp)

{

	if (system_state == SYSTEM_RUNNING) {

		mutex_lock(&zswap_init_lock);

		if (zswap_setup()) {

			mutex_unlock(&zswap_init_lock);

			return -ENODEV;

		}

		mutex_unlock(&zswap_init_lock);

	}

	if (zswap_init_state == ZSWAP_INIT_FAILED) {

		pr_err("can't enable, initialization failed\n");

		return -ENODEV;
@@ -1435,14 +1453,14 @@ static int __init zswap_debugfs_init(void) 
static void __exit zswap_debugfs_exit(void) { }

#endif



/*********************************

* module init and exit

**********************************/

static int __init init_zswap(void)

static int zswap_setup(void)

{

	struct zswap_pool *pool;

	int ret;



	if (zswap_init_state != ZSWAP_UNINIT)

		return 0;



	if (zswap_entry_cache_create()) {

		pr_err("entry cache creation failed\n");

		goto cache_fail;
@@ -1496,6 +1514,18 @@ static int __init init_zswap(void) 
	zswap_enabled = false;

	return -ENOMEM;

}



/*********************************

* module init and exit

**********************************/

static int __init init_zswap(void)

{

	/* skip init if zswap is disabled when system startup */

	if (!zswap_enabled)

		return 0;

	return zswap_setup();

}



/* must be late so crypto has time to come up */

late_initcall(init_zswap);