io-threads: remove least-rate-limit option and code

This will be unnecessary, and mostly in the way, as real fairness
guarantees are implemented.

Change-Id: Ic61ec1c9e9add58385f1a4eafcfe2cc554ceefc8
BUG: 1360402
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-on: http://review.gluster.org/14989
Smoke: Gluster Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: Gluster Build System <jenkins@build.gluster.org>

2 files changed, 2 insertions, 96 deletions

diff --git a/xlators/performance/io-threads/src/io-threads.c b/xlators/performance/io-threads/src/io-threads.c
index dd2aba3fd0a..c0bcea48e3d 100644
--- a/xlators/performance/io-threads/src/io-threads.c
+++ b/xlators/performance/io-threads/src/io-threads.c
@@ -49,69 +49,17 @@ struct volume_options options[];
         } while (0)
 
 call_stub_t *
-__iot_dequeue (iot_conf_t *conf, int *pri, struct timespec *sleep)
+__iot_dequeue (iot_conf_t *conf, int *pri)
 {
         call_stub_t  *stub = NULL;
         int           i = 0;
-	struct timeval curtv = {0,}, difftv = {0,};
 
         *pri = -1;
-	sleep->tv_sec = 0;
-	sleep->tv_nsec = 0;
         for (i = 0; i < IOT_PRI_MAX; i++) {
                 if (list_empty (&conf->reqs[i]) ||
                    (conf->ac_iot_count[i] >= conf->ac_iot_limit[i]))
                         continue;
 
-		if (i == IOT_PRI_LEAST) {
-			pthread_mutex_lock(&conf->throttle.lock);
-			if (!conf->throttle.sample_time.tv_sec) {
-				/* initialize */
-				gettimeofday(&conf->throttle.sample_time, NULL);
-			} else {
-				/*
-				 * Maintain a running count of least priority
-				 * operations that are handled over a particular
-				 * time interval. The count is provided via
-				 * state dump and is used as a measure against
-				 * least priority op throttling.
-				 */
-				gettimeofday(&curtv, NULL);
-				timersub(&curtv, &conf->throttle.sample_time,
-					 &difftv);
-				if (difftv.tv_sec >= IOT_LEAST_THROTTLE_DELAY) {
-					conf->throttle.cached_rate =
-						conf->throttle.sample_cnt;
-					conf->throttle.sample_cnt = 0;
-					conf->throttle.sample_time = curtv;
-				}
-
-				/*
-				 * If we're over the configured rate limit,
-				 * provide an absolute time to the caller that
-				 * represents the soonest we're allowed to
-				 * return another least priority request.
-				 */
-				if (conf->throttle.rate_limit &&
-				    conf->throttle.sample_cnt >=
-						conf->throttle.rate_limit) {
-					struct timeval delay;
-					delay.tv_sec = IOT_LEAST_THROTTLE_DELAY;
-					delay.tv_usec = 0;
-
-					timeradd(&conf->throttle.sample_time,
-						 &delay, &curtv);
-					TIMEVAL_TO_TIMESPEC(&curtv, sleep);
-
-					pthread_mutex_unlock(
-						&conf->throttle.lock);
-					break;
-				}
-			}
-			conf->throttle.sample_cnt++;
-			pthread_mutex_unlock(&conf->throttle.lock);
-		}
-
                 stub = list_entry (conf->reqs[i].next, call_stub_t, list);
                 conf->ac_iot_count[i]++;
                 *pri = i;
@@ -155,7 +103,6 @@ iot_worker (void *data)
         int               pri = -1;
         char              timeout = 0;
         char              bye = 0;
-	struct timespec	  sleep = {0,};
 
         conf = data;
         this = conf->this;
@@ -196,13 +143,7 @@ iot_worker (void *data)
                                 }
                         }
 
-                        stub = __iot_dequeue (conf, &pri, &sleep);
-			if (!stub && (sleep.tv_sec || sleep.tv_nsec)) {
-				pthread_cond_timedwait(&conf->cond,
-						       &conf->mutex, &sleep);
-				pthread_mutex_unlock(&conf->mutex);
-				continue;
-			}
+                        stub = __iot_dequeue (conf, &pri);
                 }
                 pthread_mutex_unlock (&conf->mutex);
 
@@ -914,10 +855,6 @@ iot_priv_dump (xlator_t *this)
         gf_proc_dump_write("least_priority_threads", "%d",
                            conf->ac_iot_limit[IOT_PRI_LEAST]);
 
-	gf_proc_dump_write("cached least rate", "%u",
-			   conf->throttle.cached_rate);
-	gf_proc_dump_write("least rate limit", "%u", conf->throttle.rate_limit);
-
         return 0;
 }
 
@@ -949,9 +886,6 @@ reconfigure (xlator_t *this, dict_t *options)
         GF_OPTION_RECONF ("enable-least-priority", conf->least_priority,
                           options, bool, out);
 
-	GF_OPTION_RECONF("least-rate-limit", conf->throttle.rate_limit, options,
-			 int32, out);
-
 	ret = 0;
 out:
 	return ret;
@@ -1021,15 +955,6 @@ init (xlator_t *this)
         GF_OPTION_INIT ("enable-least-priority", conf->least_priority,
                         bool, out);
 
-	GF_OPTION_INIT("least-rate-limit", conf->throttle.rate_limit, int32,
-		       out);
-        if ((ret = pthread_mutex_init(&conf->throttle.lock, NULL)) != 0) {
-                gf_msg (this->name, GF_LOG_ERROR, 0,
-                        IO_THREADS_MSG_INIT_FAILED,
-                        "pthread_mutex_init failed (%d)", ret);
-                goto out;
-        }
-
         conf->this = this;
 
         for (i = 0; i < IOT_PRI_MAX; i++) {
@@ -1179,14 +1104,6 @@ struct volume_options options[] = {
          .max   = 0x7fffffff,
          .default_value = "120",
         },
-	{.key	= {"least-rate-limit"},
-	 .type	= GF_OPTION_TYPE_INT,
-	 .min	= 0,
-         .max	= INT_MAX,
-	 .default_value = "0",
-	 .description = "Max number of least priority operations to handle "
-			"per-second"
-	},
 	{ .key  = {NULL},
         },
 };
diff --git a/xlators/performance/io-threads/src/io-threads.h b/xlators/performance/io-threads/src/io-threads.h
index d8eea2cf77a..6d9ea255909 100644
--- a/xlators/performance/io-threads/src/io-threads.h
+++ b/xlators/performance/io-threads/src/io-threads.h
@@ -48,15 +48,6 @@ typedef enum {
         IOT_PRI_MAX,
 } iot_pri_t;
 
-#define IOT_LEAST_THROTTLE_DELAY 1	/* sample interval in seconds */
-struct iot_least_throttle {
-	struct timeval	sample_time;	/* timestamp of current sample */
-	uint32_t	sample_cnt;	/* sample count for active interval */
-	uint32_t	cached_rate;	/* the most recently measured rate */
-	int32_t		rate_limit;	/* user-specified rate limit */
-	pthread_mutex_t	lock;
-};
-
 struct iot_conf {
         pthread_mutex_t      mutex;
         pthread_cond_t       cond;
@@ -78,8 +69,6 @@ struct iot_conf {
 
         xlator_t            *this;
         size_t              stack_size;
-
-	struct iot_least_throttle throttle;
 };
 
 typedef struct iot_conf iot_conf_t;