Make the critbit cooling off period a parameter.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@4715 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/hash_critbit.c

@@ -340,8 +340,6 @@ static struct cli_proto hcb_cmds[] = {
 
 /**********************************************************************/
 
-#define COOL_DURATION	60		/* seconds */
-
 static void *
 hcb_cleaner(void *priv)
 {
@@ -363,7 +361,7 @@ hcb_cleaner(void *priv)
 			y = (void *)&oh->u;
 			if (y->leaf[0] || y->leaf[1])
 				continue;
-			if (++oh->digest[0] > COOL_DURATION) {
+			if (++oh->digest[0] > params->critbit_cooloff) {
 				VTAILQ_REMOVE(&laylow, oh, coollist);
 #ifdef PHK
 				fprintf(stderr, "OH %p is cold enough\n", oh);

bin/varnishd/heritage.h

@@ -199,6 +199,8 @@ struct params {
 	unsigned		syslog_cli_traffic;
 
 	unsigned		http_range_support;
+
+	double			critbit_cooloff;
 };
 
 /*

bin/varnishd/mgt_param.c

@@ -817,6 +817,13 @@ static const struct parspec input_parspec[] = {
 		"Enable support for HTTP Range headers.\n",
 		EXPERIMENTAL,
 		"off", "bool" },
+	{ "critbit_cooloff", tweak_timeout_double,
+		&master.critbit_cooloff, 60, UINT_MAX,
+		"How long time the critbit hasher keeps deleted objheads "
+		"on the cooloff list.\n"
+		"A value of zero disables the ban lurker.",
+		EXPERIMENTAL,
+		"180.0", "s" },
 	{ NULL, NULL, NULL }
 };