From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net: implement emergency route cache rebulds when gc_elasticity is exceeded Date: Sun, 05 Oct 2008 10:34:54 -0700 (PDT) Message-ID: <20081005.103454.247312994.davem@davemloft.net> References: <20080930.070804.26007839.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: herbert@gondor.apana.org.au, nhorman@tuxdriver.com, netdev@vger.kernel.org, kuznet@ms2.inr.ac.ru, pekkas@netcore.fi, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net To: whydna@whydna.net Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:34100 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755001AbYJERfU (ORCPT ); Sun, 5 Oct 2008 13:35:20 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: "Andrew Dickinson" Date: Sat, 4 Oct 2008 21:45:27 -0700 > Here's the patch that Herbert's referring to. The basic idea is that > we have a flag which indicates whether or not we need to invalidate > the route cache. If any chain exceeds gc_elasticity, we set the flag > and reschedule the timer. In the worst-case, we'll invalidate the > route cache once every secret_interval; in the best-case, we never > invalidate the cache. This is a very interesting patch and idea, but... Eric showed clearly that on a completely normal well loaded system, the chain lengths exceed the elasticity all the time and it's not like these are entries we can get rid of because their refcounts are all > 1