From: Evan Hunt <each@isc.org>
Date: Thu, 25 Jul 2013 17:51:31 +0000 (-0700)
Subject: [master] perf: eliminate cache stats attach/detach
X-Git-Tag: v9.10.0a1~190
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d640b4a0ab9dec252749793f78a1ed1e8551ea19;p=thirdparty%2Fbind9.git

[master] perf: eliminate cache stats attach/detach

3622.	[tuning]	Eliminate an unnecessary lock when incrementing
			cache statistics. [RT #34339]
---

diff --git a/CHANGES b/CHANGES
index 5d7e2a1962f..52bbff4c044 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3622.	[tuning]	Eliminate an unnecessary lock when incrementing
+			cache statistics. [RT #34339]
+
 3621.	[security]	Incorrect bounds checking on private type 'keydata'
 			can lead to a remotely triggerable REQUIRE failure
 			(CVE-2013-4854). [RT #34238]
diff --git a/bin/named/query.c b/bin/named/query.c
index c805d26db1c..a592967f83b 100644
--- a/bin/named/query.c
+++ b/bin/named/query.c
@@ -1205,31 +1205,6 @@ query_isduplicate(ns_client_t *client, dns_name_t *name,
 	return (ISC_FALSE);
 }
 
-static void
-update_cachestats(dns_cache_t *cache, isc_result_t result) {
-	isc_stats_t *cachestats = NULL;
-	if (cache == NULL)
-		return;
-
-	isc_stats_attach(dns_cache_getstats(cache), &cachestats);
-	switch (result) {
-	case ISC_R_SUCCESS:
-	case DNS_R_NCACHENXDOMAIN:
-	case DNS_R_NCACHENXRRSET:
-	case DNS_R_CNAME:
-	case DNS_R_DNAME:
-	case DNS_R_GLUE:
-	case DNS_R_ZONECUT:
-		isc_stats_increment(cachestats,
-				    dns_cachestatscounter_queryhits);
-		break;
-	default:
-		isc_stats_increment(cachestats,
-				    dns_cachestatscounter_querymisses);
-	}
-	isc_stats_detach(&cachestats);
-}
-
 static isc_result_t
 query_addadditional(void *arg, dns_name_t *name, dns_rdatatype_t qtype) {
 	ns_client_t *client = arg;
@@ -1362,7 +1337,7 @@ query_addadditional(void *arg, dns_name_t *name, dns_rdatatype_t qtype) {
 				client->now, &node, fname, &cm, &ci,
 				rdataset, sigrdataset);
 
-	update_cachestats(client->view->cache, result);
+	dns_cache_updatestats(client->view->cache, result);
 	if (result == DNS_R_GLUE &&
 	    validate(client, db, fname, rdataset, sigrdataset))
 		result = ISC_R_SUCCESS;
@@ -6294,7 +6269,7 @@ query_find(ns_client_t *client, dns_fetchevent_t *event, dns_rdatatype_t qtype)
 				&node, fname, &cm, &ci, rdataset, sigrdataset);
 
 	if (db == client->view->cachedb)
-		update_cachestats(client->view->cache, result);
+		dns_cache_updatestats(client->view->cache, result);
 
  resume:
 	CTRACE("query_find: resume");
diff --git a/lib/dns/cache.c b/lib/dns/cache.c
index c1a94ed7b68..abe163b35da 100644
--- a/lib/dns/cache.c
+++ b/lib/dns/cache.c
@@ -1300,6 +1300,29 @@ dns_cache_getstats(dns_cache_t *cache) {
 	return (cache->stats);
 }
 
+void
+dns_cache_updatestats(dns_cache_t *cache, isc_result_t result) {
+	REQUIRE(VALID_CACHE(cache));
+	if (cache->stats == NULL)
+		return;
+
+	switch (result) {
+	case ISC_R_SUCCESS:
+	case DNS_R_NCACHENXDOMAIN:
+	case DNS_R_NCACHENXRRSET:
+	case DNS_R_CNAME:
+	case DNS_R_DNAME:
+	case DNS_R_GLUE:
+	case DNS_R_ZONECUT:
+		isc_stats_increment(cache->stats,
+				    dns_cachestatscounter_queryhits);
+		break;
+	default:
+		isc_stats_increment(cache->stats,
+				    dns_cachestatscounter_querymisses);
+	}
+}
+
 /*
  * XXX: Much of the following code has been copied in from statschannel.c.
  * We should refactor this into a generic function in stats.c that can be
diff --git a/lib/dns/include/dns/cache.h b/lib/dns/include/dns/cache.h
index 89a64b49ed0..5e196ffd6f9 100644
--- a/lib/dns/include/dns/cache.h
+++ b/lib/dns/include/dns/cache.h
@@ -320,6 +320,12 @@ dns_cache_dumpstats(dns_cache_t *cache, FILE *fp);
  * Dump cache statistics and status in text to 'fp'
  */
 
+void
+dns_cache_updatestats(dns_cache_t *cache, isc_result_t result);
+/*
+ * Update cache statistics based on result code in 'result'
+ */
+
 #ifdef HAVE_LIBXML2
 int
 dns_cache_renderxml(dns_cache_t *cache, xmlTextWriterPtr writer);
diff --git a/lib/dns/win32/libdns.def b/lib/dns/win32/libdns.def
index 8ecad2337f1..18b67709fad 100644
--- a/lib/dns/win32/libdns.def
+++ b/lib/dns/win32/libdns.def
@@ -74,6 +74,7 @@ dns_cache_renderxml
 dns_cache_setcachesize
 dns_cache_setcleaninginterval
 dns_cache_setfilename
+dns_cache_updatestats
 dns_cert_fromtext
 dns_cert_totext
 dns_clientinfo_init