From a5b4ace6e5ae840f47effc03b63115ddd283ea24 Mon Sep 17 00:00:00 2001
From: David Hows <howsdav@gmail.com>
Date: Fri, 27 Nov 2015 14:45:42 +1100
Subject: WTPERF - Add a multiplier to the truncate stones to deal with very
 high throughput cases

---
 bench/wtperf/wtperf.c          |  2 --
 bench/wtperf/wtperf.h          |  1 +
 bench/wtperf/wtperf_truncate.c | 27 ++++++++++++++++++++++++---
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/bench/wtperf/wtperf.c b/bench/wtperf/wtperf.c
index 9ac96862fa1..6edc29b6106 100644
--- a/bench/wtperf/wtperf.c
+++ b/bench/wtperf/wtperf.c
@@ -559,8 +559,6 @@ worker(void *arg)
 					trk = &thread->truncate;
 				else
 					trk = &thread->truncate_sleep;
-				/* Pause between truncate attempts */
-				(void)usleep(1000);
 				break;
 			}
 			goto op_err;
diff --git a/bench/wtperf/wtperf.h b/bench/wtperf/wtperf.h
index e4b9fc00798..b26e978c13b 100644
--- a/bench/wtperf/wtperf.h
+++ b/bench/wtperf/wtperf.h
@@ -116,6 +116,7 @@ struct __truncate_struct {
 	uint64_t last_total_inserts;
 	uint64_t num_stones;
 	uint64_t last_key;
+	uint64_t catchup_multiplier;
 };
 
 /* Queue entry for use with the Truncate Logic */
diff --git a/bench/wtperf/wtperf_truncate.c b/bench/wtperf/wtperf_truncate.c
index 581d1987947..7b6fc1e70ed 100644
--- a/bench/wtperf/wtperf_truncate.c
+++ b/bench/wtperf/wtperf_truncate.c
@@ -54,6 +54,9 @@ setup_truncate(CONFIG *cfg, CONFIG_THREAD *thread, WT_SESSION *session) {
 	    session, cfg->uris[0], NULL, NULL, &cursor)) != 0)
 		goto err;
 
+	/* If we find the workload getting behind we multiply the stone gap */
+	trunc_cfg->catchup_multiplier = 1;
+
 	/* How many entries between each stone. */
 	trunc_cfg->stone_gap =
 	    (workload->truncate_count * workload->truncate_pct) / 100;
@@ -133,6 +136,7 @@ run_truncate(CONFIG *cfg, CONFIG_THREAD *thread,
 	TRUNCATE_QUEUE_ENTRY *truncate_item;
 	char *truncate_key;
 	int ret, t_ret;
+	uint64_t used_stone_gap;
 
 	ret = 0;
 	trunc_cfg = &thread->trunc_cfg;
@@ -145,11 +149,28 @@ run_truncate(CONFIG *cfg, CONFIG_THREAD *thread,
 	trunc_cfg->last_total_inserts = trunc_cfg->total_inserts;
 
 	/* We are done if there isn't enough data to trigger a new milestone. */
-	if (trunc_cfg->expected_total <= trunc_cfg->needed_stones)
+	if (trunc_cfg->expected_total <= thread->workload->truncate_count)
 		return (0);
 
+	used_stone_gap = trunc_cfg->stone_gap;
+	/*
+	 * If we are falling behind and using more than one stone per lap we
+	 * should widen the stone gap for this lap to try and catch up quicker.
+	 */
+	if (trunc_cfg->expected_total >
+	    thread->workload->truncate_count + trunc_cfg->stone_gap) {
+		if (trunc_cfg->catchup_multiplier < trunc_cfg->needed_stones-1)
+			trunc_cfg->catchup_multiplier++;
+		used_stone_gap =
+		    trunc_cfg->stone_gap * trunc_cfg->catchup_multiplier;
+	} else {
+		/* Back off if we start seeing an improvement */
+		if (trunc_cfg->catchup_multiplier > 1)
+			trunc_cfg->catchup_multiplier--;
+	}
+
 	while (trunc_cfg->num_stones < trunc_cfg->needed_stones) {
-		trunc_cfg->last_key += trunc_cfg->stone_gap;
+		trunc_cfg->last_key += used_stone_gap;
 		truncate_key = calloc(cfg->key_sz, 1);
 		if (truncate_key == NULL) {
 			lprintf(cfg, ENOMEM, 0,
@@ -165,7 +186,7 @@ run_truncate(CONFIG *cfg, CONFIG_THREAD *thread,
 		}
 		generate_key(cfg, truncate_key, trunc_cfg->last_key);
 		truncate_item->key = truncate_key;
-		truncate_item->diff = trunc_cfg->stone_gap;
+		truncate_item->diff = used_stone_gap;
 		TAILQ_INSERT_TAIL(&cfg->stone_head, truncate_item, q);
 		trunc_cfg->num_stones++;
 	}
-- 
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