From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933045AbXGQJEO (ORCPT ); Tue, 17 Jul 2007 05:04:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760834AbXGQJD7 (ORCPT ); Tue, 17 Jul 2007 05:03:59 -0400 Received: from mx10.go2.pl ([193.17.41.74]:54194 "EHLO poczta.o2.pl" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756295AbXGQJD6 (ORCPT ); Tue, 17 Jul 2007 05:03:58 -0400 Date: Tue, 17 Jul 2007 11:12:53 +0200 From: Jarek Poplawski To: Olaf Kirch Cc: Ingo Molnar , Linus Torvalds , linux-kernel@vger.kernel.org, davem@davemloft.net Subject: Re: [patch] revert: [NET]: Fix races in net_rx_action vs netpoll Message-ID: <20070717091253.GA2049@ff.dom.local> References: <20070716091236.GA10718@elte.hu> <20070717061458.GB1640@ff.dom.local> <200707170955.38536.olaf.kirch@oracle.com> <200707171028.36451.olaf.kirch@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200707171028.36451.olaf.kirch@oracle.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 17, 2007 at 10:28:34AM +0200, Olaf Kirch wrote: > On Tuesday 17 July 2007 09:55, Olaf Kirch wrote: > > What I find more problematic about this portion of code though > > is that once a net_device is over quota, net_rx_action will > > loop for up to one jiffy, even if there's just this one device on > > the poll_list. > > Duh, wrong. For every loop, it'll add dev->weight to dev->quota, > so it'll be fine very soon. After your patch only two things can be different here: dev->poll_list and this flag. Since Ingo offered testing it should be easy to check after moving the check of "your" flag to __netif_rx_complete, and skipping only list_del on true. Jarek P.