From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH] bridge: fdb cleanup runs too often Date: Tue, 15 Jun 2010 09:14:12 -0700 Message-ID: <20100615091412.17e0d656@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from mail.vyatta.com ([76.74.103.46]:37386 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752358Ab0FOQOO (ORCPT ); Tue, 15 Jun 2010 12:14:14 -0400 Sender: netdev-owner@vger.kernel.org List-ID: It is common in end-node, non STP bridges to set forwarding delay to zero; which causes the forwarding database cleanup to run every clock tick. Change to run only as soon as needed or at next ageing timer interval which ever is sooner. Use round_jiffies_up macro rather than attempting round up by changing value. Signed-off-by: Stephen Hemminger --- This is 2.6.35 bug fix, and should also be considered for stable because of the performance impact. --- a/net/bridge/br_fdb.c 2010-06-15 08:47:57.624465674 -0700 +++ b/net/bridge/br_fdb.c 2010-06-15 08:53:45.407855065 -0700 @@ -128,7 +128,7 @@ void br_fdb_cleanup(unsigned long _data) { struct net_bridge *br = (struct net_bridge *)_data; unsigned long delay = hold_time(br); - unsigned long next_timer = jiffies + br->forward_delay; + unsigned long next_timer = jiffies + br->ageing_time; int i; spin_lock_bh(&br->hash_lock); @@ -149,9 +149,7 @@ void br_fdb_cleanup(unsigned long _data) } spin_unlock_bh(&br->hash_lock); - /* Add HZ/4 to ensure we round the jiffies upwards to be after the next - * timer, otherwise we might round down and will have no-op run. */ - mod_timer(&br->gc_timer, round_jiffies(next_timer + HZ/4)); + mod_timer(&br->gc_timer, round_jiffies_up(next_timer)); } /* Completely flush all dynamic entries in forwarding database.*/