mm/zswap: Convert pool to hotplug state machine
Install the callbacks via the state machine. Multi state is used to address the
per-pool notifier. Uppon adding of the intance the callback is invoked for all
online CPUs so the manual init can go.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mm@kvack.org
Cc: Seth Jennings <sjenning@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161126231350.10321-13-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 62f51a4..c7d0d76 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -66,6 +66,7 @@ enum cpuhp_state {
CPUHP_TRACE_RB_PREPARE,
CPUHP_MM_ZS_PREPARE,
CPUHP_MM_ZSWP_MEM_PREPARE,
+ CPUHP_MM_ZSWP_POOL_PREPARE,
CPUHP_TIMERS_DEAD,
CPUHP_NOTF_ERR_INJ_PREPARE,
CPUHP_MIPS_SOC_PREPARE,
diff --git a/mm/zswap.c b/mm/zswap.c
index b13aa57..067a0d6 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -118,7 +118,7 @@ struct zswap_pool {
struct kref kref;
struct list_head list;
struct work_struct work;
- struct notifier_block notifier;
+ struct hlist_node node;
char tfm_name[CRYPTO_MAX_ALG_NAME];
};
@@ -376,77 +376,34 @@ static int zswap_dstmem_dead(unsigned int cpu)
return 0;
}
-static int __zswap_cpu_comp_notifier(struct zswap_pool *pool,
- unsigned long action, unsigned long cpu)
+static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
{
+ struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
struct crypto_comp *tfm;
- switch (action) {
- case CPU_UP_PREPARE:
- if (WARN_ON(*per_cpu_ptr(pool->tfm, cpu)))
- break;
- tfm = crypto_alloc_comp(pool->tfm_name, 0, 0);
- if (IS_ERR_OR_NULL(tfm)) {
- pr_err("could not alloc crypto comp %s : %ld\n",
- pool->tfm_name, PTR_ERR(tfm));
- return NOTIFY_BAD;
- }
- *per_cpu_ptr(pool->tfm, cpu) = tfm;
- break;
- case CPU_DEAD:
- case CPU_UP_CANCELED:
- tfm = *per_cpu_ptr(pool->tfm, cpu);
- if (!IS_ERR_OR_NULL(tfm))
- crypto_free_comp(tfm);
- *per_cpu_ptr(pool->tfm, cpu) = NULL;
- break;
- default:
- break;
+ if (WARN_ON(*per_cpu_ptr(pool->tfm, cpu)))
+ return 0;
+
+ tfm = crypto_alloc_comp(pool->tfm_name, 0, 0);
+ if (IS_ERR_OR_NULL(tfm)) {
+ pr_err("could not alloc crypto comp %s : %ld\n",
+ pool->tfm_name, PTR_ERR(tfm));
+ return -ENOMEM;
}
- return NOTIFY_OK;
-}
-
-static int zswap_cpu_comp_notifier(struct notifier_block *nb,
- unsigned long action, void *pcpu)
-{
- unsigned long cpu = (unsigned long)pcpu;
- struct zswap_pool *pool = container_of(nb, typeof(*pool), notifier);
-
- return __zswap_cpu_comp_notifier(pool, action, cpu);
-}
-
-static int zswap_cpu_comp_init(struct zswap_pool *pool)
-{
- unsigned long cpu;
-
- memset(&pool->notifier, 0, sizeof(pool->notifier));
- pool->notifier.notifier_call = zswap_cpu_comp_notifier;
-
- cpu_notifier_register_begin();
- for_each_online_cpu(cpu)
- if (__zswap_cpu_comp_notifier(pool, CPU_UP_PREPARE, cpu) ==
- NOTIFY_BAD)
- goto cleanup;
- __register_cpu_notifier(&pool->notifier);
- cpu_notifier_register_done();
+ *per_cpu_ptr(pool->tfm, cpu) = tfm;
return 0;
-
-cleanup:
- for_each_online_cpu(cpu)
- __zswap_cpu_comp_notifier(pool, CPU_UP_CANCELED, cpu);
- cpu_notifier_register_done();
- return -ENOMEM;
}
-static void zswap_cpu_comp_destroy(struct zswap_pool *pool)
+static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
{
- unsigned long cpu;
+ struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
+ struct crypto_comp *tfm;
- cpu_notifier_register_begin();
- for_each_online_cpu(cpu)
- __zswap_cpu_comp_notifier(pool, CPU_UP_CANCELED, cpu);
- __unregister_cpu_notifier(&pool->notifier);
- cpu_notifier_register_done();
+ tfm = *per_cpu_ptr(pool->tfm, cpu);
+ if (!IS_ERR_OR_NULL(tfm))
+ crypto_free_comp(tfm);
+ *per_cpu_ptr(pool->tfm, cpu) = NULL;
+ return 0;
}
/*********************************
@@ -527,6 +484,7 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
struct zswap_pool *pool;
char name[38]; /* 'zswap' + 32 char (max) num + \0 */
gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
+ int ret;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool) {
@@ -551,7 +509,9 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
goto error;
}
- if (zswap_cpu_comp_init(pool))
+ ret = cpuhp_state_add_instance(CPUHP_MM_ZSWP_POOL_PREPARE,
+ &pool->node);
+ if (ret)
goto error;
pr_debug("using %s compressor\n", pool->tfm_name);
@@ -605,7 +565,7 @@ static void zswap_pool_destroy(struct zswap_pool *pool)
{
zswap_pool_debug("destroying", pool);
- zswap_cpu_comp_destroy(pool);
+ cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node);
free_percpu(pool->tfm);
zpool_destroy_pool(pool->zpool);
kfree(pool);
@@ -1212,6 +1172,13 @@ static int __init init_zswap(void)
goto dstmem_fail;
}
+ ret = cpuhp_setup_state_multi(CPUHP_MM_ZSWP_POOL_PREPARE,
+ "mm/zswap_pool:prepare",
+ zswap_cpu_comp_prepare,
+ zswap_cpu_comp_dead);
+ if (ret)
+ goto hp_fail;
+
pool = __zswap_pool_create_fallback();
if (!pool) {
pr_err("pool creation failed\n");
@@ -1228,6 +1195,8 @@ static int __init init_zswap(void)
return 0;
pool_fail:
+ cpuhp_remove_state_nocalls(CPUHP_MM_ZSWP_POOL_PREPARE);
+hp_fail:
cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);
dstmem_fail:
zswap_entry_cache_destroy();