From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] ipv4: tcp: dont cache unconfirmed intput dst Date: Wed, 27 Jun 2012 17:08:30 -0700 (PDT) Message-ID: <20120627.170830.811332455348620174.davem@davemloft.net> References: <20120627.153454.30398632011109264.davem@davemloft.net> <20120627.164418.1928194990434756968.davem@davemloft.net> <20120627.170101.99084491660488389.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, hans.schillstrom@ericsson.com To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:48342 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753427Ab2F1AIb (ORCPT ); Wed, 27 Jun 2012 20:08:31 -0400 In-Reply-To: <20120627.170101.99084491660488389.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: From: David Miller Date: Wed, 27 Jun 2012 17:01:01 -0700 (PDT) > There are quite a number of unwanted side effects from this change, so > I think we'll have to revert unless you can fix up all of the relevant > cases quickly. Actually I've decided to revert it now. Whilst this was a swell idea, there is no way for you to know if we should really create a cached route or not. Even if you could, there is a lot of logic you'll need to code up so that, f.e., once we determine that we've got a DST_NOCACHE route when we move to established state, we can insert it into the routing cache and not mark it DST_NOCACHE any longer. But even if we did that, we're going to eat 2 uncached route lookups for every new incoming legitimate connection.