From ae53812b2ccfd7842fa6430081465ed90f18814b Mon Sep 17 00:00:00 2001 From: Shehjar Tikoo Date: Wed, 1 Apr 2009 14:00:06 -0700 Subject: io-threads: Allow scaling to be switched off The default is also to provide no scaling. For both, ordered and unordered request pools, when scaling is off, we maintain atleast the minimum number of threads specified in the volfile. Signed-off-by: Anand V. Avati --- xlators/performance/io-threads/src/io-threads.c | 65 +++++++++++++++++++++---- 1 file changed, 55 insertions(+), 10 deletions(-) (limited to 'xlators/performance/io-threads/src/io-threads.c') diff --git a/xlators/performance/io-threads/src/io-threads.c b/xlators/performance/io-threads/src/io-threads.c index 1d255d972..fbd002267 100644 --- a/xlators/performance/io-threads/src/io-threads.c +++ b/xlators/performance/io-threads/src/io-threads.c @@ -41,6 +41,30 @@ void iot_startup_workers (iot_worker_t **workers, int start_idx, int count, void * iot_worker_unordered (void *arg); void * iot_worker_ordered (void *arg); +int +iot_unordered_request_balancer (iot_conf_t *conf) +{ + long int rand = 0; + int idx = 0; + + /* Decide which thread will service the request. + * FIXME: This should change into some form of load-balancing. + * */ + rand = random (); + + /* If scaling is on, we can choose from any thread + * that has been allocated upto, max_o_threads, but + * with scaling off, we'll never have threads more + * than min_o_threads. + */ + if (iot_unordered_scaling_on (conf)) + idx = (rand % conf->max_u_threads); + else + idx = (rand % conf->min_u_threads); + + return idx; +} + void iot_schedule_unordered (iot_conf_t *conf, inode_t *inode, @@ -50,10 +74,7 @@ iot_schedule_unordered (iot_conf_t *conf, iot_worker_t *selected_worker = NULL; iot_request_t *req = NULL; - /* First decide which thread will service the request. - * FIXME: This should change into some form of load-balancing. - * */ - idx = (random() % conf->max_u_threads); + idx = iot_unordered_request_balancer (conf); selected_worker = conf->uworkers[idx]; req = iot_init_request (stub); @@ -73,6 +94,33 @@ iot_schedule_unordered (iot_conf_t *conf, pthread_mutex_unlock (&selected_worker->qlock); } +/* Assumes inode lock is held. */ +int +iot_ordered_request_balancer (iot_conf_t *conf, + inode_t *inode) +{ + int ctxret = 0; + long int rand = 0; + uint64_t idx = 0; + + ctxret = __inode_ctx_get (inode, conf->this, &idx); + if (ctxret < 0) { + rand = random (); + /* If scaling is on, we can choose from any thread + * that has been allocated upto, max_o_threads, but + * with scaling off, we'll never have threads more + * than min_o_threads. + */ + if (iot_ordered_scaling_on (conf)) + idx = (rand % conf->max_o_threads); + else + idx = (rand % conf->min_o_threads); + __inode_ctx_put (inode, conf->this, idx); + } + + return idx; +} + void iot_schedule_ordered (iot_conf_t *conf, inode_t *inode, @@ -81,7 +129,6 @@ iot_schedule_ordered (iot_conf_t *conf, uint64_t idx = 0; iot_worker_t *selected_worker = NULL; iot_request_t * req = NULL; - int ctxret = 0; if (inode == NULL) { gf_log (conf->this->name, GF_LOG_ERROR, @@ -91,11 +138,7 @@ iot_schedule_ordered (iot_conf_t *conf, req = iot_init_request (stub); LOCK (&inode->lock); { - ctxret = __inode_ctx_get (inode, conf->this, &idx); - if (ctxret < 0) { - idx = (random () % conf->max_o_threads); - __inode_ctx_put (inode, conf->this, idx); - } + idx = iot_ordered_request_balancer (conf, inode); /* inode lock once acquired, cannot be left here * because other gluster main threads might be * contending on it to append a request for this file. @@ -1762,12 +1805,14 @@ init (xlator_t *this) conf->max_u_threads = IOT_MAX_THREADS; conf->min_u_threads = IOT_MIN_THREADS; conf->u_idle_time = IOT_DEFAULT_IDLE; + conf->u_scaling = IOT_SCALING_OFF; /* Init params for ordered workers. */ pthread_mutex_init (&conf->otlock, NULL); conf->max_o_threads = IOT_MAX_THREADS; conf->min_o_threads = IOT_MIN_THREADS; conf->o_idle_time = IOT_DEFAULT_IDLE; + conf->o_scaling = IOT_SCALING_OFF; conf->this = this; workers_init (conf); -- cgit