From cab7a7e5b6c5c2638b00c72559ff9fb715583c98 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Sun, 27 Nov 2016 00:13:40 +0100 Subject: 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 Cc: linux-mm@kvack.org Cc: Seth Jennings Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161126231350.10321-13-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- mm/zswap.c | 99 +++++++++++++++++++++----------------------------------------- 1 file changed, 34 insertions(+), 65 deletions(-) (limited to 'mm/zswap.c') diff --git a/mm/zswap.c b/mm/zswap.c index b13aa5706348..067a0d62f318 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; - } - 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); -} + if (WARN_ON(*per_cpu_ptr(pool->tfm, cpu))) + return 0; -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(); + 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; + } + *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(); -- cgit v1.2.3-59-g8ed1b