From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evgeniy Polyakov Subject: Re: REDIRECT in nat OUTPUT Date: Sun, 13 Jul 2008 18:09:30 +0400 Message-ID: <20080713140930.GA23238@2ka.mipt.ru> References: <200807120424.56462.denys@visp.net.lb> <20080712062812.GA7609@2ka.mipt.ru> <200807121655.44547.denys@visp.net.lb> <200807121740.25789.denys@visp.net.lb> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, David Miller , Eric Dumazet To: Denys Fedoryshchenko Return-path: Received: from relay.2ka.mipt.ru ([194.85.80.65]:53096 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751972AbYGMOJn (ORCPT ); Sun, 13 Jul 2008 10:09:43 -0400 Content-Disposition: inline In-Reply-To: <200807121740.25789.denys@visp.net.lb> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Sat, Jul 12, 2008 at 05:40:25PM +0300, Denys Fedoryshchenko (denys@visp.net.lb) wrote: > Seems i found something. After issuing ethtool -K lo tso on i got significant performance improvement. > Why it is not on by default? > Without it performance is VERY poor. TSO over loopback turns to be GSO, which allows to aggregate multiple packets into single frame. If system is not CPU bound, then it is likely REDIRECT problem. If I understood you corerctly, loopback performance is always good without REDIRECT, but fails to miserable level when apprpriate rule is used? -- Evgeniy Polyakov