fib_trie: Drop unnecessary calls to leaf_pull_suffix

[ Upstream commit 1513069edcf8dd86cfd8d5daef482b97d6b93df6 ]

It was reported that update_suffix was taking a long time on systems where
a large number of leaves were attached to a single node.  As it turns out
fib_table_flush was calling update_suffix for each leaf that didn't have all
of the aliases stripped from it.  As a result, on this large node removing
one leaf would result in us calling update_suffix for every other leaf on
the node.

The fix is to just remove the calls to leaf_pull_suffix since they are
redundant as we already have a call in resize that will go through and
update the suffix length for the node before we exit out of
fib_table_flush or fib_table_flush_external.

Reported-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 09b62e17dd8cba4b1041de5f208180d278010604..210ceca2640c1b3ba6b92a4163a2f867537c3df3 100644 (file)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1780,8 +1780,6 @@ void fib_table_flush_external(struct fib_table *tb)
                if (hlist_empty(&n->leaf)) {
                        put_child_root(pn, n->key, NULL);
                        node_free(n);
-               } else {
-                       leaf_pull_suffix(pn, n);
                }
        }
 }
@@ -1852,8 +1850,6 @@ int fib_table_flush(struct fib_table *tb)
                if (hlist_empty(&n->leaf)) {
                        put_child_root(pn, n->key, NULL);
                        node_free(n);
-               } else {
-                       leaf_pull_suffix(pn, n);
                }
        }