[rrd-developers] [PATCH 2/2] Introduce "-m" argument to reduce calls to realloc().

[kevin brintnall]

---
 doc/rrdcached.pod |    9 +++++++++
 src/rrd_daemon.c  |   23 ++++++++++++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/doc/rrdcached.pod b/doc/rrdcached.pod
index 043e020..5e8728f 100644
--- a/doc/rrdcached.pod
+++ b/doc/rrdcached.pod
@@ -18,6 +18,7 @@ B<rrdcached>
 [-F]
 [-g]
 [B<-b>E<nbsp>I<base_dir>E<nbsp>[B<-B>]]
+[B<-m>E<nbsp>I<alloc_size>]
 
 =head1 DESCRIPTION
 
@@ -197,6 +198,14 @@ Only permit writes into the base directory specified in B<-b> (and any
 sub-directories).  This does B<NOT> detect symbolic links.  Paths
 containing C<../> will also be blocked.
 
+=item B<-m> I<alloc_size>
+
+Allocate value pointers in chunks of I<alloc_size>.  This may improve CPU
+utilization on machines with slow C<realloc()> implementations, in
+exchange for slightly higher memory utilization.  The default isE<nbsp>1.
+Do not set this more than the B<-w> value divided by your average RRD step
+size.
+
 =back
 
 =head1 AFFECTED RRDTOOL COMMANDS
diff --git a/src/rrd_daemon.c b/src/rrd_daemon.c
index 4c84f19..79ea17b 100644
--- a/src/rrd_daemon.c
+++ b/src/rrd_daemon.c
@@ -174,7 +174,8 @@ struct cache_item_s
 {
   char *file;
   char **values;
-  size_t values_num;
+  size_t values_num;		/* number of valid pointers */
+  size_t values_alloc;		/* number of allocated pointers */
   time_t last_flush_time;
   time_t last_update_stamp;
 #define CI_FLAGS_IN_TREE  (1<<0)
@@ -251,6 +252,7 @@ static char *config_pid_file = NULL;
 static char *config_base_dir = NULL;
 static size_t _config_base_dir_len = 0;
 static int config_write_base_only = 0;
+static size_t config_alloc_chunk = 1;
 
 static listen_socket_t **config_listen_address_list = NULL;
 static size_t config_listen_address_list_len = 0;
@@ -638,6 +640,7 @@ static void wipe_ci_values(cache_item_t *ci, time_t when)
 {
   ci->values = NULL;
   ci->values_num = 0;
+  ci->values_alloc = 0;
 
   ci->last_flush_time = when;
   if (config_write_jitter > 0)
@@ -1434,7 +1437,8 @@ static int handle_request_update (HANDLER_PROTO) /* {{{ */
     else
       ci->last_update_stamp = stamp;
 
-    if (!rrd_add_strdup(&ci->values, &ci->values_num, value))
+    if (!rrd_add_strdup_chunk(&ci->values, &ci->values_num, value,
+                              &ci->values_alloc, config_alloc_chunk))
     {
       RRDD_LOG (LOG_ERR, "handle_request_update: rrd_add_strdup failed.");
       continue;
@@ -2746,7 +2750,7 @@ static int read_options (int argc, char **argv) /* {{{ */
   char **permissions = NULL;
   size_t permissions_len = 0;
 
-  while ((option = getopt(argc, argv, "gl:P:f:w:z:t:Bb:p:Fj:h?")) != -1)
+  while ((option = getopt(argc, argv, "gl:P:f:w:z:t:Bb:p:Fj:m:h?")) != -1)
   {
     switch (option)
     {
@@ -3003,6 +3007,19 @@ static int read_options (int argc, char **argv) /* {{{ */
       }
       break;
 
+      case 'm':
+      {
+        int temp = atoi(optarg);
+        if (temp > 0)
+          config_alloc_chunk = temp;
+        else
+        {
+          fprintf(stderr, "Invalid allocation size: %s\n", optarg);
+          status = 10;
+        }
+      }
+      break;
+
       case 'h':
       case '?':
         printf ("RRDCacheD %s\n"
-- 
1.6.4