From: Yann Ylavic <ylavic@apache.org>
Date: Sat, 25 Jun 2016 18:56:28 +0000 (+0000)
Subject: Follow up to r1737447: fix max_spare_threads lower bound.
X-Git-Tag: 2.5.0-alpha~1471
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7932f3c76b053cb5ab90adaa38812c1a23ec6f7f;p=thirdparty%2Fapache%2Fhttpd.git

Follow up to r1737447: fix max_spare_threads lower bound.
Suggested by: Rick Houser <rick.houser jackson.com>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1750218 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/server/mpm/event/event.c b/server/mpm/event/event.c
index 58ff4307fcd..28a2bc0ebb2 100644
--- a/server/mpm/event/event.c
+++ b/server/mpm/event/event.c
@@ -3145,10 +3145,16 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s)
         ap_daemons_limit = num_buckets;
     if (ap_daemons_to_start < num_buckets)
         ap_daemons_to_start = num_buckets;
+    /* We want to create as much children at a time as the number of buckets,
+     * so to optimally accept connections (evenly distributed accross buckets).
+     * Thus min_spare_threads should at least maintain num_buckets children,
+     * and max_spare_threads allow num_buckets more children w/o triggering
+     * immediately (e.g. num_buckets idle threads margin, one per bucket).
+     */
     if (min_spare_threads < threads_per_child * (num_buckets - 1) + num_buckets)
         min_spare_threads = threads_per_child * (num_buckets - 1) + num_buckets;
-    if (max_spare_threads < min_spare_threads + threads_per_child * num_buckets)
-        max_spare_threads = min_spare_threads + threads_per_child * num_buckets;
+    if (max_spare_threads < min_spare_threads + (threads_per_child + 1) * num_buckets)
+        max_spare_threads = min_spare_threads + (threads_per_child + 1) * num_buckets;
 
     /* If we're doing a graceful_restart then we're going to see a lot
      * of children exiting immediately when we get into the main loop
diff --git a/server/mpm/worker/worker.c b/server/mpm/worker/worker.c
index 9c49d832cc5..d5846d768e7 100644
--- a/server/mpm/worker/worker.c
+++ b/server/mpm/worker/worker.c
@@ -1838,10 +1838,16 @@ static int worker_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s)
         ap_daemons_limit = num_buckets;
     if (ap_daemons_to_start < num_buckets)
         ap_daemons_to_start = num_buckets;
+    /* We want to create as much children at a time as the number of buckets,
+     * so to optimally accept connections (evenly distributed accross buckets).
+     * Thus min_spare_threads should at least maintain num_buckets children,
+     * and max_spare_threads allow num_buckets more children w/o triggering
+     * immediately (e.g. num_buckets idle threads margin, one per bucket).
+     */
     if (min_spare_threads < threads_per_child * (num_buckets - 1) + num_buckets)
         min_spare_threads = threads_per_child * (num_buckets - 1) + num_buckets;
-    if (max_spare_threads < min_spare_threads + threads_per_child * num_buckets)
-        max_spare_threads = min_spare_threads + threads_per_child * num_buckets;
+    if (max_spare_threads < min_spare_threads + (threads_per_child + 1) * num_buckets)
+        max_spare_threads = min_spare_threads + (threads_per_child + 1) * num_buckets;
 
     /* If we're doing a graceful_restart then we're going to see a lot
      * of children exiting immediately when we get into the main loop