[PATCH 4.1 144/159] fib_trie: Drop unnecessary calls to leaf_pull_suffix

Greg Kroah-Hartman
2015-09-26T21:21:37Z

From: Alexander Duyck <alexander.h.duyck@redhat.com>

[ 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>
---
net/ipv4/fib_trie.c | 4 ----
1 file changed, 4 deletions(-)

--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1780,8 +1780,6 @@ void fib_table_flush_external(struct fib
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);
}
}