From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] loopback: better handling of packet drops Date: Fri, 17 Apr 2009 03:51:12 -0700 (PDT) Message-ID: <20090417.035112.171173490.davem@davemloft.net> References: <49E84B99.1080502@cosmosbay.com> <49E854A4.1010204@cosmosbay.com> <49E85AFD.6080407@cosmosbay.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: dada1@cosmosbay.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:49339 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1759920AbZDQKvV (ORCPT ); Fri, 17 Apr 2009 06:51:21 -0400 In-Reply-To: <49E85AFD.6080407@cosmosbay.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Fri, 17 Apr 2009 12:33:33 +0200 > Splitting netif_rx() with a helper function boosts tbench > performance by 1%, because we can avoid two tests (about netpoll and > timestamping) Loopback is not a special device no matter how much you wish it might be :-) This is why I haven't really pursued any further those patches I showed you that treat local TCP connections specially, it just had the realy possibility to break clever things people might be doing over loopback using the packet scheduler classifier and packet scheduler actions. I also think it is valid to use netpoll over loopback, especially for testing. So please undo this part of the patch. You always try to combine multiple distinct changes, and I would have taken just your TX drop change if you hadn't added this __netif_rx() stuff to it :-(