diff options
| -rw-r--r-- | thread.c | 30 |
1 files changed, 24 insertions, 6 deletions
@@ -47,8 +47,10 @@ static CQ_ITEM *cqi_freelist; static pthread_mutex_t cqi_freelist_lock; static pthread_mutex_t *item_locks; -/* TODO: Make this a function of the # of threads */ -#define ITEM_LOCKS 4000 +/* size of the item lock hash table */ +static uint32_t item_lock_count; +/* size - 1 for lookup masking */ +static uint32_t item_lock_mask; static LIBEVENT_DISPATCHER_THREAD dispatcher_thread; @@ -69,11 +71,11 @@ static pthread_cond_t init_cond; static void thread_libevent_process(int fd, short which, void *arg); void item_lock(uint32_t hv) { - mutex_lock(&item_locks[hv % ITEM_LOCKS]); + mutex_lock(&item_locks[hv & item_lock_mask]); } void item_unlock(uint32_t hv) { - pthread_mutex_unlock(&item_locks[hv % ITEM_LOCKS]); + pthread_mutex_unlock(&item_locks[hv & item_lock_mask]); } /* @@ -623,6 +625,7 @@ void slab_stats_aggregate(struct thread_stats *stats, struct slab_stats *out) { */ void thread_init(int nthreads, struct event_base *main_base) { int i; + int power; pthread_mutex_init(&cache_lock, NULL); pthread_mutex_init(&stats_lock, NULL); @@ -633,12 +636,27 @@ void thread_init(int nthreads, struct event_base *main_base) { pthread_mutex_init(&cqi_freelist_lock, NULL); cqi_freelist = NULL; - item_locks = calloc(ITEM_LOCKS, sizeof(pthread_mutex_t)); + /* Want a wide lock table, but don't waste memory */ + if (nthreads < 3) { + power = 10; + } else if (nthreads < 4) { + power = 11; + } else if (nthreads < 5) { + power = 12; + } else { + /* 8192 buckets, and central locks don't scale much past 5 threads */ + power = 13; + } + + item_lock_count = ((unsigned long int)1 << (power)); + item_lock_mask = item_lock_count - 1; + + item_locks = calloc(item_lock_count, sizeof(pthread_mutex_t)); if (! item_locks) { perror("Can't allocate item locks"); exit(1); } - for (i = 0; i < ITEM_LOCKS; i++) { + for (i = 0; i < item_lock_count; i++) { pthread_mutex_init(&item_locks[i], NULL); } |