Patch "fib_trie: Drop unnecessary calls to leaf_pull_suffix" has been added to the 4.1-stable tree

Patch "fib_trie: Drop unnecessary calls to leaf_pull_suffix" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    fib_trie: Drop unnecessary calls to leaf_pull_suffix

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     fib_trie-drop-unnecessary-calls-to-leaf_pull_suffix.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Sep 26 11:13:07 PDT 2015
From: Alexander Duyck <alexander.h.duyck@redhat.com>
Date: Mon, 27 Jul 2015 13:08:06 -0700
Subject: fib_trie: Drop unnecessary calls to leaf_pull_suffix

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);
 		}
 	}
 


Patches currently in stable-queue which might be from alexander.h.duyck@redhat.com are

queue-4.1/ipv4-off-by-one-in-continuation-handling-in-proc-net-route.patch
queue-4.1/fib_trie-drop-unnecessary-calls-to-leaf_pull_suffix.patch