diff options
Diffstat (limited to 'libglusterfs/src/mem-pool.c')
| -rw-r--r-- | libglusterfs/src/mem-pool.c | 311 |
1 files changed, 169 insertions, 142 deletions
diff --git a/libglusterfs/src/mem-pool.c b/libglusterfs/src/mem-pool.c index ea9cc6881b1..2d5a12b0a00 100644 --- a/libglusterfs/src/mem-pool.c +++ b/libglusterfs/src/mem-pool.c @@ -362,6 +362,30 @@ free: FREE(ptr); } +#if defined(GF_DISABLE_MEMPOOL) + +struct mem_pool * +mem_pool_new_fn(glusterfs_ctx_t *ctx, unsigned long sizeof_type, + unsigned long count, char *name) +{ + struct mem_pool *new; + + new = GF_MALLOC(sizeof(struct mem_pool), gf_common_mt_mem_pool); + if (!new) + return NULL; + + new->sizeof_type = sizeof_type; + return new; +} + +void +mem_pool_destroy(struct mem_pool *pool) +{ + GF_FREE(pool); +} + +#else /* !GF_DISABLE_MEMPOOL */ + static pthread_mutex_t pool_lock = PTHREAD_MUTEX_INITIALIZER; static struct list_head pool_threads; static pthread_mutex_t pool_free_lock = PTHREAD_MUTEX_INITIALIZER; @@ -371,12 +395,10 @@ static size_t pool_list_size; static __thread per_thread_pool_list_t *thread_pool_list = NULL; -#if !defined(GF_DISABLE_MEMPOOL) #define N_COLD_LISTS 1024 #define POOL_SWEEP_SECS 30 typedef struct { - struct list_head death_row; pooled_obj_hdr_t *cold_lists[N_COLD_LISTS]; unsigned int n_cold_lists; } sweep_state_t; @@ -393,36 +415,33 @@ static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER; static unsigned int init_count = 0; static pthread_t sweeper_tid; -gf_boolean_t +static bool collect_garbage(sweep_state_t *state, per_thread_pool_list_t *pool_list) { unsigned int i; per_thread_pool_t *pt_pool; - gf_boolean_t poisoned; (void)pthread_spin_lock(&pool_list->lock); - poisoned = pool_list->poison != 0; - if (!poisoned) { - for (i = 0; i < NPOOLS; ++i) { - pt_pool = &pool_list->pools[i]; - if (pt_pool->cold_list) { - if (state->n_cold_lists >= N_COLD_LISTS) { - break; - } - state->cold_lists[state->n_cold_lists++] = pt_pool->cold_list; + for (i = 0; i < NPOOLS; ++i) { + pt_pool = &pool_list->pools[i]; + if (pt_pool->cold_list) { + if (state->n_cold_lists >= N_COLD_LISTS) { + (void)pthread_spin_unlock(&pool_list->lock); + return true; } - pt_pool->cold_list = pt_pool->hot_list; - pt_pool->hot_list = NULL; + state->cold_lists[state->n_cold_lists++] = pt_pool->cold_list; } + pt_pool->cold_list = pt_pool->hot_list; + pt_pool->hot_list = NULL; } (void)pthread_spin_unlock(&pool_list->lock); - return poisoned; + return false; } -void +static void free_obj_list(pooled_obj_hdr_t *victim) { pooled_obj_hdr_t *next; @@ -434,82 +453,96 @@ free_obj_list(pooled_obj_hdr_t *victim) } } -void * +static void * pool_sweeper(void *arg) { sweep_state_t state; per_thread_pool_list_t *pool_list; - per_thread_pool_list_t *next_pl; - per_thread_pool_t *pt_pool; - unsigned int i; - gf_boolean_t poisoned; + uint32_t i; + bool pending; /* * This is all a bit inelegant, but the point is to avoid doing * expensive things (like freeing thousands of objects) while holding a - * global lock. Thus, we split each iteration into three passes, with + * global lock. Thus, we split each iteration into two passes, with * only the first and fastest holding the lock. */ + pending = true; + for (;;) { - sleep(POOL_SWEEP_SECS); + /* If we know there's pending work to do (or it's the first run), we + * do collect garbage more often. */ + sleep(pending ? POOL_SWEEP_SECS / 5 : POOL_SWEEP_SECS); + (void)pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL); - INIT_LIST_HEAD(&state.death_row); state.n_cold_lists = 0; + pending = false; /* First pass: collect stuff that needs our attention. */ (void)pthread_mutex_lock(&pool_lock); - list_for_each_entry_safe(pool_list, next_pl, &pool_threads, thr_list) + list_for_each_entry(pool_list, &pool_threads, thr_list) { - (void)pthread_mutex_unlock(&pool_lock); - poisoned = collect_garbage(&state, pool_list); - (void)pthread_mutex_lock(&pool_lock); - - if (poisoned) { - list_move(&pool_list->thr_list, &state.death_row); + if (collect_garbage(&state, pool_list)) { + pending = true; } } (void)pthread_mutex_unlock(&pool_lock); - /* Second pass: free dead pools. */ - (void)pthread_mutex_lock(&pool_free_lock); - list_for_each_entry_safe(pool_list, next_pl, &state.death_row, thr_list) - { - for (i = 0; i < NPOOLS; ++i) { - pt_pool = &pool_list->pools[i]; - free_obj_list(pt_pool->cold_list); - free_obj_list(pt_pool->hot_list); - pt_pool->hot_list = pt_pool->cold_list = NULL; - } - list_del(&pool_list->thr_list); - list_add(&pool_list->thr_list, &pool_free_threads); - } - (void)pthread_mutex_unlock(&pool_free_lock); - - /* Third pass: free cold objects from live pools. */ + /* Second pass: free cold objects from live pools. */ for (i = 0; i < state.n_cold_lists; ++i) { free_obj_list(state.cold_lists[i]); } (void)pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL); } + + return NULL; } void -mem_pool_thread_destructor(void) +mem_pool_thread_destructor(per_thread_pool_list_t *pool_list) { - per_thread_pool_list_t *pool_list = thread_pool_list; + per_thread_pool_t *pt_pool; + uint32_t i; - /* The pool-sweeper thread will take it from here. - * - * We can change 'poison' here without taking locks because the change - * itself doesn't interact with other parts of the code and a simple write - * is already atomic from the point of view of the processor. - * - * This change can modify what mem_put() does, but both possibilities are - * fine until the sweeper thread kicks in. The real synchronization must be - * between mem_put() and the sweeper thread. */ + if (pool_list == NULL) { + pool_list = thread_pool_list; + } + + /* The current thread is terminating. None of the allocated objects will + * be used again. We can directly destroy them here instead of delaying + * it until the next sweeper loop. */ if (pool_list != NULL) { - pool_list->poison = 1; + /* Remove pool_list from the global list to avoid that sweeper + * could touch it. */ + pthread_mutex_lock(&pool_lock); + list_del(&pool_list->thr_list); + pthread_mutex_unlock(&pool_lock); + + /* We need to protect hot/cold changes from potential mem_put() calls + * that reference this pool_list. Once poison is set to true, we are + * sure that no one else will touch hot/cold lists. The only possible + * race is when at the same moment a mem_put() is adding a new item + * to the hot list. We protect from that by taking pool_list->lock. + * After that we don't need the lock to destroy the hot/cold lists. */ + pthread_spin_lock(&pool_list->lock); + pool_list->poison = true; + pthread_spin_unlock(&pool_list->lock); + + for (i = 0; i < NPOOLS; i++) { + pt_pool = &pool_list->pools[i]; + + free_obj_list(pt_pool->hot_list); + pt_pool->hot_list = NULL; + + free_obj_list(pt_pool->cold_list); + pt_pool->cold_list = NULL; + } + + pthread_mutex_lock(&pool_free_lock); + list_add(&pool_list->thr_list, &pool_free_threads); + pthread_mutex_unlock(&pool_free_lock); + thread_pool_list = NULL; } } @@ -537,6 +570,22 @@ mem_pools_preinit(void) init_done = GF_MEMPOOL_INIT_EARLY; } +static __attribute__((destructor)) void +mem_pools_postfini(void) +{ + /* TODO: This function should destroy all per thread memory pools that + * are still alive, but this is not possible right now because glibc + * starts calling destructors as soon as exit() is called, and + * gluster doesn't ensure that all threads have been stopped before + * calling exit(). Existing threads would crash when they try to use + * memory or they terminate if we destroy things here. + * + * When we propertly terminate all threads, we can add the needed + * code here. Till then we need to leave the memory allocated. Most + * probably this function will be executed on process termination, + * so the memory will be released anyway by the system. */ +} + /* Call mem_pools_init() once threading has been configured completely. This * prevent the pool_sweeper thread from getting killed once the main() thread * exits during deamonizing. */ @@ -569,10 +618,6 @@ mem_pools_fini(void) */ break; case 1: { - per_thread_pool_list_t *pool_list; - per_thread_pool_list_t *next_pl; - unsigned int i; - /* if mem_pools_init() was not called, sweeper_tid will be invalid * and the functions will error out. That is not critical. In all * other cases, the sweeper_tid will be valid and the thread gets @@ -580,32 +625,11 @@ mem_pools_fini(void) (void)pthread_cancel(sweeper_tid); (void)pthread_join(sweeper_tid, NULL); - /* At this point all threads should have already terminated, so - * it should be safe to destroy all pending per_thread_pool_list_t - * structures that are stored for each thread. */ - mem_pool_thread_destructor(); - - /* free all objects from all pools */ - list_for_each_entry_safe(pool_list, next_pl, &pool_threads, - thr_list) - { - for (i = 0; i < NPOOLS; ++i) { - free_obj_list(pool_list->pools[i].hot_list); - free_obj_list(pool_list->pools[i].cold_list); - pool_list->pools[i].hot_list = NULL; - pool_list->pools[i].cold_list = NULL; - } - - list_del(&pool_list->thr_list); - FREE(pool_list); - } - - list_for_each_entry_safe(pool_list, next_pl, &pool_free_threads, - thr_list) - { - list_del(&pool_list->thr_list); - FREE(pool_list); - } + /* There could be threads still running in some cases, so we can't + * destroy pool_lists in use. We can also not destroy unused + * pool_lists because some allocated objects may still be pointing + * to them. */ + mem_pool_thread_destructor(NULL); init_done = GF_MEMPOOL_INIT_DESTROY; /* Fall through. */ @@ -616,21 +640,29 @@ mem_pools_fini(void) pthread_mutex_unlock(&init_mutex); } -#else -void -mem_pools_init(void) -{ -} void -mem_pools_fini(void) -{ -} -void -mem_pool_thread_destructor(void) +mem_pool_destroy(struct mem_pool *pool) { -} + if (!pool) + return; -#endif + /* remove this pool from the owner (glusterfs_ctx_t) */ + LOCK(&pool->ctx->lock); + { + list_del(&pool->owner); + } + UNLOCK(&pool->ctx->lock); + + /* free this pool, but keep the mem_pool_shared */ + GF_FREE(pool); + + /* + * Pools are now permanent, so the mem_pool->pool is kept around. All + * of the objects *in* the pool will eventually be freed via the + * pool-sweeper thread, and this way we don't have to add a lot of + * reference-counting complexity. + */ +} struct mem_pool * mem_pool_new_fn(glusterfs_ctx_t *ctx, unsigned long sizeof_type, @@ -681,6 +713,7 @@ mem_pool_new_fn(glusterfs_ctx_t *ctx, unsigned long sizeof_type, new->sizeof_type = sizeof_type; new->count = count; new->name = name; + new->xl_name = THIS->name; new->pool = pool; GF_ATOMIC_INIT(new->active, 0); #ifdef DEBUG @@ -698,21 +731,6 @@ mem_pool_new_fn(glusterfs_ctx_t *ctx, unsigned long sizeof_type, return new; } -void * -mem_get0(struct mem_pool *mem_pool) -{ - void *ptr = mem_get(mem_pool); - if (ptr) { -#if defined(GF_DISABLE_MEMPOOL) - memset(ptr, 0, mem_pool->sizeof_type); -#else - memset(ptr, 0, AVAILABLE_SIZE(mem_pool->pool->power_of_two)); -#endif - } - - return ptr; -} - per_thread_pool_list_t * mem_get_pool_list(void) { @@ -747,13 +765,21 @@ mem_get_pool_list(void) } } + /* There's no need to take pool_list->lock, because this is already an + * atomic operation and we don't need to synchronize it with any change + * in hot/cold lists. */ + pool_list->poison = false; + (void)pthread_mutex_lock(&pool_lock); - pool_list->poison = 0; list_add(&pool_list->thr_list, &pool_threads); (void)pthread_mutex_unlock(&pool_lock); thread_pool_list = pool_list; + /* Ensure that all memory objects associated to the new pool_list are + * destroyed when the thread terminates. */ + gf_thread_needs_cleanup(); + return pool_list; } @@ -813,6 +839,23 @@ mem_get_from_pool(struct mem_pool *mem_pool) return retval; } +#endif /* GF_DISABLE_MEMPOOL */ + +void * +mem_get0(struct mem_pool *mem_pool) +{ + void *ptr = mem_get(mem_pool); + if (ptr) { +#if defined(GF_DISABLE_MEMPOOL) + memset(ptr, 0, mem_pool->sizeof_type); +#else + memset(ptr, 0, AVAILABLE_SIZE(mem_pool->pool->power_of_two)); +#endif + } + + return ptr; +} + void * mem_get(struct mem_pool *mem_pool) { @@ -857,6 +900,14 @@ mem_put(void *ptr) /* Not one of ours; don't touch it. */ return; } + + if (!hdr->pool_list) { + gf_msg_callingfn("mem-pool", GF_LOG_CRITICAL, EINVAL, + LG_MSG_INVALID_ARG, + "invalid argument hdr->pool_list NULL"); + return; + } + pool_list = hdr->pool_list; pt_pool = &pool_list->pools[hdr->power_of_two - POOL_SMALLEST]; @@ -879,27 +930,3 @@ mem_put(void *ptr) } #endif /* GF_DISABLE_MEMPOOL */ } - -void -mem_pool_destroy(struct mem_pool *pool) -{ - if (!pool) - return; - - /* remove this pool from the owner (glusterfs_ctx_t) */ - LOCK(&pool->ctx->lock); - { - list_del(&pool->owner); - } - UNLOCK(&pool->ctx->lock); - - /* free this pool, but keep the mem_pool_shared */ - GF_FREE(pool); - - /* - * Pools are now permanent, so the mem_pool->pool is kept around. All - * of the objects *in* the pool will eventually be freed via the - * pool-sweeper thread, and this way we don't have to add a lot of - * reference-counting complexity. - */ -} |