From: Witold Kręcicki <wpk@isc.org>
Date: Tue, 28 Jan 2020 10:05:07 +0000 (+0100)
Subject: Make ns_client mctxpool more thread-friendly by sharding it by netmgr threadid
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d9763b968e192ad105d0351c4d4f380a63c3d7f;p=thirdparty%2Fbind9.git

Make ns_client mctxpool more thread-friendly by sharding it by netmgr threadid
---

diff --git a/bin/named/server.c b/bin/named/server.c
index 6a818a31493..d14f63c866e 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -9544,7 +9544,7 @@ run_server(isc_task_t *task, isc_event_t *event) {
 					  named_g_nm,
 					  named_g_dispatchmgr,
 					  server->task, named_g_udpdisp, geoip,
-					  &server->interfacemgr),
+					  named_g_cpus, &server->interfacemgr),
 		   "creating interface manager");
 
 	CHECKFATAL(isc_timer_create(named_g_timermgr, isc_timertype_inactive,
diff --git a/lib/ns/client.c b/lib/ns/client.c
index d0653d2fa7a..3f60bcee6e2 100644
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -2214,34 +2214,16 @@ ns__client_tcpconn(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
 static void
 get_clientmctx(ns_clientmgr_t *manager, isc_mem_t **mctxp) {
 	isc_mem_t *clientmctx;
-#if CLIENT_NMCTXS > 0
 	unsigned int nextmctx;
-#endif
-
 	MTRACE("clientmctx");
 
-#if CLIENT_NMCTXS > 0
-	LOCK(&manager->lock);
-	if (isc_nm_tid() >= 0) {
-		nextmctx = isc_nm_tid();
-	} else {
-		nextmctx = manager->nextmctx++;
-		if (manager->nextmctx == CLIENT_NMCTXS)
-			manager->nextmctx = 0;
-
-		INSIST(nextmctx < CLIENT_NMCTXS);
+	int tid = isc_nm_tid();
+	if (tid < 0) {
+		tid = isc_random_uniform(manager->ncpus);
 	}
-
+	int rand = isc_random_uniform(CLIENT_NMCTXS_PERCPU);
+	nextmctx = (rand * manager->ncpus) + tid;
 	clientmctx = manager->mctxpool[nextmctx];
-	if (clientmctx == NULL) {
-		isc_mem_create(&clientmctx);
-		isc_mem_setname(clientmctx, "client", NULL);
-		manager->mctxpool[nextmctx] = clientmctx;
-	}
-	UNLOCK(&manager->lock);
-#else
-	clientmctx = manager->mctx;
-#endif
 
 	isc_mem_attach(clientmctx, mctxp);
 }
@@ -2399,21 +2381,18 @@ clientmgr_detach(ns_clientmgr_t **mp) {
 
 static void
 clientmgr_destroy(ns_clientmgr_t *manager) {
-#if CLIENT_NMCTXS > 0
 	int i;
-#endif
 
 	MTRACE("clientmgr_destroy");
 
 	isc_refcount_destroy(&manager->references);
 	manager->magic = 0;
 
-#if CLIENT_NMCTXS > 0
-	for (i = 0; i < CLIENT_NMCTXS; i++) {
-		if (manager->mctxpool[i] != NULL)
-			isc_mem_detach(&manager->mctxpool[i]);
+	for (i = 0; i < manager->ncpus * CLIENT_NMCTXS_PERCPU; i++) {
+		isc_mem_detach(&manager->mctxpool[i]);
 	}
-#endif
+	isc_mem_put(manager->mctx, manager->mctxpool,
+		    manager->ncpus * CLIENT_NMCTXS_PERCPU * sizeof(isc_mem_t*));
 
 	if (manager->interface != NULL) {
 		ns_interface_detach(&manager->interface);
@@ -2440,13 +2419,12 @@ clientmgr_destroy(ns_clientmgr_t *manager) {
 isc_result_t
 ns_clientmgr_create(isc_mem_t *mctx, ns_server_t *sctx, isc_taskmgr_t *taskmgr,
 		    isc_timermgr_t *timermgr, ns_interface_t *interface,
-		    ns_clientmgr_t **managerp)
+		    int ncpus, ns_clientmgr_t **managerp)
 {
 	ns_clientmgr_t *manager;
 	isc_result_t result;
-#if CLIENT_NMCTXS > 0
 	int i;
-#endif
+	int npools;
 
 	manager = isc_mem_get(mctx, sizeof(*manager));
 	*manager = (ns_clientmgr_t) { .magic = 0 };
@@ -2478,11 +2456,17 @@ ns_clientmgr_create(isc_mem_t *mctx, ns_server_t *sctx, isc_taskmgr_t *taskmgr,
 	ns_server_attach(sctx, &manager->sctx);
 
 	ISC_LIST_INIT(manager->recursing);
-#if CLIENT_NMCTXS > 0
-	manager->nextmctx = 0;
-	for (i = 0; i < CLIENT_NMCTXS; i++)
-		manager->mctxpool[i] = NULL; /* will be created on-demand */
-#endif
+
+	manager->ncpus = ncpus;
+	npools = CLIENT_NMCTXS_PERCPU * manager->ncpus;
+	manager->mctxpool = isc_mem_get(manager->mctx,
+					npools * sizeof(isc_mem_t*));
+	for (i = 0; i < npools; i++) {
+		manager->mctxpool[i] = NULL;
+		isc_mem_create(&manager->mctxpool[i]);
+		isc_mem_setname(manager->mctxpool[i], "client", NULL);
+	}
+
 	manager->magic = MANAGER_MAGIC;
 
 	MTRACE("create");
diff --git a/lib/ns/include/ns/client.h b/lib/ns/include/ns/client.h
index d1e4f28f335..ce58ed3d4db 100644
--- a/lib/ns/include/ns/client.h
+++ b/lib/ns/include/ns/client.h
@@ -85,7 +85,7 @@
 #define NS_CLIENT_SEND_BUFFER_SIZE		4096
 #define NS_CLIENT_RECV_BUFFER_SIZE		4096
 
-#define CLIENT_NMCTXS				100
+#define CLIENT_NMCTXS_PERCPU			8
 /*%<
  * Number of 'mctx pools' for clients. (Should this be configurable?)
  * When enabling threads, we use a pool of memory contexts shared by
@@ -166,6 +166,7 @@ struct ns_clientmgr {
 	isc_timermgr_t *	timermgr;
 	isc_task_t *		excl;
 	isc_refcount_t		references;
+	int			ncpus;
 
 	/* Attached by clients, needed for e.g. recursion */
 	isc_task_t **		taskpool;
@@ -180,11 +181,8 @@ struct ns_clientmgr {
 	isc_mutex_t		reclock;
 	client_list_t		recursing;    /*%< Recursing clients */
 
-#if CLIENT_NMCTXS > 0
 	/*%< mctx pool for clients. */
-	unsigned int		nextmctx;
-	isc_mem_t *		mctxpool[CLIENT_NMCTXS];
-#endif
+	isc_mem_t **		mctxpool;
 };
 
 /*% nameserver client structure */
@@ -364,7 +362,7 @@ ns_client_settimeout(ns_client_t *client, unsigned int seconds);
 
 isc_result_t
 ns_clientmgr_create(isc_mem_t *mctx, ns_server_t *sctx, isc_taskmgr_t *taskmgr,
-		    isc_timermgr_t *timermgr, ns_interface_t *ifp,
+		    isc_timermgr_t *timermgr, ns_interface_t *ifp, int ncpus,
 		    ns_clientmgr_t **managerp);
 /*%<
  * Create a client manager.
diff --git a/lib/ns/include/ns/interfacemgr.h b/lib/ns/include/ns/interfacemgr.h
index 0212460cc4d..2ff490a196e 100644
--- a/lib/ns/include/ns/interfacemgr.h
+++ b/lib/ns/include/ns/interfacemgr.h
@@ -103,7 +103,7 @@ ns_interfacemgr_create(isc_mem_t *mctx, ns_server_t *sctx,
 		       isc_socketmgr_t *socketmgr, isc_nm_t *nm,
 		       dns_dispatchmgr_t *dispatchmgr, isc_task_t *task,
 		       unsigned int udpdisp, dns_geoip_databases_t *geoip,
-		       ns_interfacemgr_t **mgrp);
+		       int ncpus, ns_interfacemgr_t **mgrp);
 /*%<
  * Create a new interface manager.
  *
diff --git a/lib/ns/interfacemgr.c b/lib/ns/interfacemgr.c
index df1fe63aab5..982a678bc96 100644
--- a/lib/ns/interfacemgr.c
+++ b/lib/ns/interfacemgr.c
@@ -75,6 +75,7 @@ struct ns_interfacemgr {
 	isc_timermgr_t *	timermgr;	/*%< Timer manager. */
 	isc_socketmgr_t *	socketmgr;	/*%< Socket manager. */
 	isc_nm_t *		nm;		/*%< Net manager. */
+	int			ncpus;		/*%< Number of workers . */
 	dns_dispatchmgr_t *	dispatchmgr;
 	unsigned int		generation;	/*%< Current generation no. */
 	ns_listenlist_t *	listenon4;
@@ -181,6 +182,7 @@ ns_interfacemgr_create(isc_mem_t *mctx,
 		       isc_task_t *task,
 		       unsigned int udpdisp,
 		       dns_geoip_databases_t *geoip,
+		       int ncpus,
 		       ns_interfacemgr_t **mgrp)
 {
 	isc_result_t result;
@@ -219,6 +221,7 @@ ns_interfacemgr_create(isc_mem_t *mctx,
 	mgr->listenon4 = NULL;
 	mgr->listenon6 = NULL;
 	mgr->udpdisp = udpdisp;
+	mgr->ncpus = ncpus;
 	atomic_init(&mgr->shuttingdown, false);
 
 	ISC_LIST_INIT(mgr->interfaces);
@@ -425,7 +428,7 @@ ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
 
 	result = ns_clientmgr_create(mgr->mctx, mgr->sctx,
 				     mgr->taskmgr, mgr->timermgr, ifp,
-				     &ifp->clientmgr);
+				     mgr->ncpus, &ifp->clientmgr);
 	if (result != ISC_R_SUCCESS) {
 		isc_log_write(IFMGR_COMMON_LOGARGS, ISC_LOG_ERROR,
 			      "ns_clientmgr_create() failed: %s",
diff --git a/lib/ns/tests/nstest.c b/lib/ns/tests/nstest.c
index d4314693d2f..b4f1367596d 100644
--- a/lib/ns/tests/nstest.c
+++ b/lib/ns/tests/nstest.c
@@ -237,7 +237,7 @@ create_managers(void) {
 
 	CHECK(ns_interfacemgr_create(mctx, sctx, taskmgr, timermgr,
 				     socketmgr, nm, dispatchmgr, maintask,
-				     ncpus, NULL, &interfacemgr));
+				     ncpus, NULL, 1, &interfacemgr));
 
 	CHECK(ns_listenlist_default(mctx, port, -1, true, &listenon));
 	ns_interfacemgr_setlistenon4(interfacemgr, listenon);