remove unnecessary argument to find_deepest_zonecut()

a minor bit of code refactoring - the 'node' argument wasn't being used; it was just being treated as a local variable.
experiment: improve locking around decref()
2024-09-16 17:08:34 -07:00 · 2024-09-16 17:08:34 -07:00 · 2024-09-16 17:08:34 -07:00 · 2024-09-16 17:08:34 -07:00 · 2024-09-16 17:08:34 -07:00 · 2024-09-16 17:08:34 -07:00
8 changed files with 389 additions and 559 deletions
--- a/lib/dns/include/dns/rdataslab.h
+++ b/lib/dns/include/dns/rdataslab.h
@@ -75,7 +75,7 @@ struct dns_slabheader {
 	dns_ttl_t	      ttl;
 	dns_typepair_t	      type;
 	atomic_uint_least16_t attributes;
-	dns_trust_t	      trust;
+	atomic_uint_fast16_t  trust;

 	unsigned int heap_index;
 	/*%<
--- a/lib/dns/qp.c
+++ b/lib/dns/qp.c
@@ -1058,7 +1058,7 @@ dns_qpmulti_memusage(dns_qpmulti_t *multi) {

 	dns_qp_memusage_t memusage = dns_qp_memusage(qp);

-	if (qp->transaction_mode == QP_UPDATE) {
+	if (qp->transaction_mode == QP_UPDATE && qp->usage != NULL) {
 		memusage.bytes -= QP_CHUNK_BYTES;
 		memusage.bytes += qp->usage[qp->bump].used *
 				  sizeof(dns_qpnode_t);
--- a/lib/dns/qp_p.h
+++ b/lib/dns/qp_p.h
@@ -141,7 +141,7 @@ enum {
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 #define QP_CHUNK_LOG 7
 #else
-#define QP_CHUNK_LOG 10
+#define QP_CHUNK_LOG 12
 #endif

 STATIC_ASSERT(6 <= QP_CHUNK_LOG && QP_CHUNK_LOG <= 20,
--- a/lib/dns/qpcache.c
+++ b/lib/dns/qpcache.c
--- a/lib/dns/rdataslab.c
+++ b/lib/dns/rdataslab.c
@@ -1413,9 +1413,7 @@ static void
 rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust) {
 	dns_slabheader_t *header = dns_slabheader_fromrdataset(rdataset);

-	dns_db_locknode(header->db, header->node, isc_rwlocktype_write);
 	header->trust = rdataset->trust = trust;
-	dns_db_unlocknode(header->db, header->node, isc_rwlocktype_write);
 }

 static void
--- a/lib/isc/include/isc/loop.h
+++ b/lib/isc/include/isc/loop.h
@@ -225,4 +225,14 @@ isc_loop_shuttingdown(isc_loop_t *loop);
 *
 * \li 'loop' is a valid loop and the loop tid matches the current tid.
 */
+
+void
+isc_loop_rcu_barrier(isc_loop_t *loop);
+/*%<
+ * Triggers an rcu_barrier() call at the end of the current loop tick.
+ *
+ * Requires:
+ *
+ * \li 'loop' is a valid loop and the loop tid matches the current tid.
+ */
 ISC_LANG_ENDDECLS
--- a/lib/isc/loop.c
+++ b/lib/isc/loop.c
@@ -237,7 +237,7 @@ loop_init(isc_loop_t *loop, isc_loopmgr_t *loopmgr, uint32_t tid,

 static void
 quiescent_cb(uv_prepare_t *handle) {
-	UNUSED(handle);
+	isc_loop_t *loop = uv_handle_get_data(handle);

 #if defined(RCU_QSBR)
 	/* safe memory reclamation */
@@ -248,6 +248,10 @@ quiescent_cb(uv_prepare_t *handle) {
 #else
 	INSIST(!rcu_read_ongoing());
 #endif
+
+	if (loop->rcu_barrier) {
+		rcu_barrier();
+	}
 }

 static void
@@ -693,3 +697,11 @@ isc_loop_shuttingdown(isc_loop_t *loop) {

 	return (loop->shuttingdown);
 }
+
+void
+isc_loop_rcu_barrier(isc_loop_t *loop) {
+	REQUIRE(VALID_LOOP(loop));
+	REQUIRE(loop->tid == isc_tid());
+
+	loop->rcu_barrier = true;
+}
--- a/lib/isc/loop_p.h
+++ b/lib/isc/loop_p.h
@@ -76,6 +76,8 @@ struct isc_loop {

 	/* safe memory reclamation */
 	uv_prepare_t quiescent;
+
+	bool rcu_barrier;
 };

 /*
Author	SHA1	Message	Date
Evan Hunt	7a2b054275	remove unnecessary argument to find_deepest_zonecut() a minor bit of code refactoring - the 'node' argument wasn't being used; it was just being treated as a local variable.	2024-09-16 17:08:34 -07:00
Evan Hunt	92157a8279	experiment: improve locking around decref() instead of always calling decref() with a node lock, we now only acquire the lock if the node needs to be cleaned or deleted.	2024-09-16 17:08:34 -07:00
Evan Hunt	5011360deb	experiment: make header->trust atomic	2024-09-16 17:08:34 -07:00
Evan Hunt	3577c748f4	experiment: increase QP chunk size	2024-09-16 17:08:34 -07:00
Evan Hunt	5a07bea738	in findnode, use a read transaction when possible when findnode() is called with the 'create' flag set, instead of automatically opening a write transaction, we will now try to look up the name with a read transaction, and only open a write transaction if that failed.	2024-09-16 17:08:34 -07:00
Evan Hunt	c7cb8e2143	reduce node locking some calls to bindrdataset were node-locked; this is no longer necessary.	2024-09-16 17:08:34 -07:00
Evan Hunt	63920bcaa8	access node attributes atomically in the qpcnode struct, the .delegating, .nsec, and .dirty members are now atomic, enabling us to avoid acquiring the node lock when those are the only things we need to check. also, renamed the check_zonecut() function to the more correctly descriptive has_dname().	2024-09-16 17:08:34 -07:00
Ondřej Surý	be0f1bcdf7	compact the cache database less often to speed up the cache, compact the database only when nodes have been added or removed.	2024-09-16 17:08:34 -07:00
Ondřej Surý	93aa99802e	add an isc_loop_rcu_barrier() for memory cleanup to finish when adding data to the cache while over memory limits, add an RCU barrier to ensure that memory is cleaned right away.	2024-09-16 17:08:34 -07:00
Ondřej Surý	9b79e9761b	Add a function to call rcu_barrier once per loop isc_loop_rcu_barrier() sets a flag so that rcu_barrier() will be called at the end of the current loop tick. This allows us to minimize time spent synchronizing between threads.	2024-09-16 17:08:34 -07:00
Evan Hunt	18ad5314cb	use dns_qpmulti instead of dns_qp in the cache replace the single-threaded dns_qp objects in the qpcache database with dns_qpmulti and eliminate the tree lock.	2024-09-16 17:08:28 -07:00