dhcp/backport-optimize-the-slabheader-placement-for-certain-RRtype.patch

From 8ef414a7f38a04cfc11df44adaedaf3126fa3878 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Mon, 29 Jan 2024 16:36:30 +0100
Subject: [PATCH] Optimize the slabheader placement for certain RRTypes
 
Mark the infrastructure RRTypes as "priority" types and place them at
the beginning of the rdataslab header data graph.  The non-priority
types either go right after the priority types (if any).
 
(cherry picked from commit 3ac482be7fd058d284e89873021339579fad0615)
 
Conflict:NA
Reference:https://gitlab.isc.org/isc-projects/bind9/-/commit/8ef414a7f38a04cfc11df44adaedaf3126fa3878
 
---
 bind/bind-9.11.36/lib/dns/rbtdb.c | 44 +++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)
 
diff --git a/bind/bind-9.11.36/lib/dns/rbtdb.c b/bind/bind-9.11.36/lib/dns/rbtdb.c
index 3ee1876..3d76ca1 100644
--- a/bind/bind-9.11.36/lib/dns/rbtdb.c
+++ b/bind/bind-9.11.36/lib/dns/rbtdb.c
@@ -1164,6 +1164,30 @@ set_ttl(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, dns_ttl_t newttl) {
 		isc_heap_decreased(heap, header->heap_index);
 }
 
+static bool
+prio_type(rbtdb_rdatatype_t type) {
+	switch (type) {
+	case dns_rdatatype_soa:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_soa):
+	case dns_rdatatype_a:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_a):
+	case dns_rdatatype_aaaa:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_aaaa):
+	case dns_rdatatype_nsec:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec):
+	case dns_rdatatype_nsec3:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_nsec3):
+	case dns_rdatatype_ns:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_ns):
+	case dns_rdatatype_ds:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_ds):
+	case dns_rdatatype_cname:
+	case RBTDB_RDATATYPE_VALUE(dns_rdatatype_rrsig, dns_rdatatype_cname):
+		return (true);
+	}
+	return (false);
+}
+
 /*%
  * These functions allow the heap code to rank the priority of each
  * element.  It returns true if v1 happens "sooner" than v2.
@@ -6176,6 +6200,7 @@ add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, rbtdb_version_t *rbtversion,
 {
 	rbtdb_changed_t *changed = NULL;
 	rdatasetheader_t *topheader, *topheader_prev, *header, *sigheader;
+	rdatasetheader_t *prioheader = NULL;
 	unsigned char *merged;
 	isc_result_t result;
 	bool header_nx;
@@ -6317,6 +6342,9 @@ add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, rbtdb_version_t *rbtversion,
 	for (topheader = rbtnode->data;
 	     topheader != NULL;
 	     topheader = topheader->next) {
+		if (prio_type(topheader->type)) {
+			prioheader = topheader;
+		}
 		if (topheader->type == newheader->type ||
 		    topheader->type == negtype)
 			break;
@@ -6672,9 +6700,21 @@ add32(dns_rbtdb_t *rbtdb, dns_rbtnode_t *rbtnode, rbtdb_version_t *rbtversion,
 			/*
 			 * No rdatasets of the given type exist at the node.
 			 */
-			newheader->next = rbtnode->data;
 			newheader->down = NULL;
-			rbtnode->data = newheader;
+
+			if (prio_type(newheader->type)) {
+				/* This is a priority type, prepend it */
+				newheader->next = rbtnode->data;
+				rbtnode->data = newheader;
+			} else if (prioheader != NULL) {
+				/* Append after the priority headers */
+				newheader->next = prioheader->next;
+				prioheader->next = newheader;
+			} else {
+				/* There were no priority headers */
+				newheader->next = rbtnode->data;
+				rbtnode->data = newheader;
+			}
 		}
 	}
 
-- 
2.33.0