zebra: improve efficiency of depends_find()

Do less malloc and free in depends_find(), when looking for
a singleton nexthop in the nhg hash.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
index e920ab812b83934db889d4932608262c31ff1d85..4f41406a5ca69d775029dac091b0968e614b9c18 100644 (file)
--- a/zebra/zebra_nhg.c
+++ b/zebra/zebra_nhg.c
@@ -49,7 +49,8 @@ DEFINE_MTYPE_STATIC(ZEBRA, NHG_CTX, "Nexthop Group Context");
 /* id counter to keep in sync with kernel */
 uint32_t id_counter;
 
-static struct nhg_hash_entry *depends_find(struct nexthop *nh, afi_t afi);
+static struct nhg_hash_entry *depends_find(const struct nexthop *nh,
+                                          afi_t afi);
 static void depends_add(struct nhg_connected_tree_head *head,
                        struct nhg_hash_entry *depend);
 static struct nhg_hash_entry *
@@ -1047,25 +1048,24 @@ int zebra_nhg_kernel_del(uint32_t id)
 }
 
 /* Some dependency helper functions */
-static struct nhg_hash_entry *depends_find(struct nexthop *nh, afi_t afi)
+static struct nhg_hash_entry *depends_find(const struct nexthop *nh, afi_t afi)
 {
-       struct nexthop *lookup = NULL;
+       struct nexthop lookup;
        struct nhg_hash_entry *nhe = NULL;
 
        if (!nh)
                goto done;
 
-       copy_nexthops(&lookup, nh, NULL);
-
-       /* Clear it, in case its a group */
-       nexthops_free(lookup->next);
-       nexthops_free(lookup->prev);
-       lookup->next = NULL;
-       lookup->prev = NULL;
+       /* Capture a snapshot of this single nh; it might be part of a list,
+        * so we need to make a standalone copy.
+        */
+       memset(&lookup, 0, sizeof(lookup));
+       nexthop_copy(&lookup, nh, NULL);
 
-       nhe = zebra_nhg_find_nexthop(0, lookup, afi, 0);
+       nhe = zebra_nhg_find_nexthop(0, &lookup, afi, 0);
 
-       nexthops_free(lookup);
+       /* The copy may have allocated labels; free them if necessary. */
+       nexthop_del_labels(&lookup);
 
 done:
        return nhe;