diff --git a/ChangeLog b/ChangeLog
index 2ae76b730..b2ba41351 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,12 @@
 Changes in version 0.2.1.16-?? - 2009-??-??
+  o Major performance improvements (on 0.2.0.x):
+    - Disable and refactor some debugging checks that forced a linear scan
+      over the whole server-side DNS cache.  These accounted for over 50%
+      of CPU time on a relatively busy exit node's gprof profile. Found by
+      Jacob.
+    - Disable some debugging checks that appeared in exit node profile
+      data.
+
   o Minor bugfixes (on 0.2.0.x):
     - Log correct error messages for DNS-related network errors on
       Windows.
diff --git a/src/or/dns.c b/src/or/dns.c
index ad5b5de40..74852b0f7 100644
--- a/src/or/dns.c
+++ b/src/or/dns.c
@@ -736,15 +736,25 @@ void
 assert_connection_edge_not_dns_pending(edge_connection_t *conn)
 {
   pending_connection_t *pend;
-  cached_resolve_t **resolve;
+  cached_resolve_t search;
 
+#if 1
+  cached_resolve_t *resolve;
+  strlcpy(search.address, conn->_base.address, sizeof(search.address));
+  resolve = HT_FIND(cache_map, &cache_root, &search);
+  if (!resolve)
+    return;
+  for (pend = resolve->pending_connections; pend; pend = pend->next) {
+    tor_assert(pend->conn != conn);
+  }
+#else
+  cached_resolve_t **resolve;
   HT_FOREACH(resolve, cache_map, &cache_root) {
-    for (pend = (*resolve)->pending_connections;
-         pend;
-         pend = pend->next) {
+    for (pend = (*resolve)->pending_connections; pend; pend = pend->next) {
       tor_assert(pend->conn != conn);
     }
   }
+#endif
 }
 
 /** Log an error and abort if any connection waiting for a DNS resolve is
diff --git a/src/or/main.c b/src/or/main.c
index a26fd0eff..8fc712bba 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -451,7 +451,7 @@ conn_read_callback(int fd, short event, void *_conn)
 
   log_debug(LD_NET,"socket %d wants to read.",conn->s);
 
-  assert_connection_ok(conn, time(NULL));
+  /* assert_connection_ok(conn, time(NULL)); */
 
   if (connection_handle_read(conn) < 0) {
     if (!conn->marked_for_close) {
@@ -483,7 +483,7 @@ conn_write_callback(int fd, short events, void *_conn)
 
   LOG_FN_CONN(conn, (LOG_DEBUG, LD_NET, "socket %d wants to write.",conn->s));
 
-  assert_connection_ok(conn, time(NULL));
+  /* assert_connection_ok(conn, time(NULL)); */
 
   if (connection_handle_write(conn, 0) < 0) {
     if (!conn->marked_for_close) {
@@ -529,7 +529,7 @@ conn_close_if_marked(int i)
     return 0; /* nothing to see here, move along */
   now = time(NULL);
   assert_connection_ok(conn, now);
-  assert_all_pending_dns_resolves_ok();
+  /* assert_all_pending_dns_resolves_ok(); */
 
   log_debug(LD_NET,"Cleaning up connection (fd %d).",conn->s);
   if ((conn->s >= 0 || conn->linked_conn) && connection_wants_to_flush(conn)) {