Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752679Ab0HPKtF (ORCPT ); Mon, 16 Aug 2010 06:49:05 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:59936 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750740Ab0HPKtC (ORCPT ); Mon, 16 Aug 2010 06:49:02 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=OJRdG7HwA3DYWAnoLybXxiFmWOpVS7w+1OCuuVrtalh5bdwuFAt10wW6Rvy4WfT8F1 Jz5NPvj9+sCXZmqd+VLfxv8oUWm9M5PtZ5UUXBxe1eVuNng8QeuU/Hlk3f1E+NyMy/JG 28UdEnJCbRGZHX5CL14ewVvkDqXqVGNyJmtJw= Date: Mon, 16 Aug 2010 10:48:59 +0000 From: Jarek Poplawski To: Eric Dumazet Cc: David Miller , torvalds@linux-foundation.org, akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Patrick McHardy Subject: Re: [GIT] Networking Message-ID: <20100816104859.GA9178@ff.dom.local> References: <20100816095325.GA8547@ff.dom.local> <1281955361.2524.35.camel@edumazet-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1281955361.2524.35.camel@edumazet-laptop> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1374 Lines: 32 On Mon, Aug 16, 2010 at 12:42:41PM +0200, Eric Dumazet wrote: > Le lundi 16 ao??t 2010 ?? 09:53 +0000, Jarek Poplawski a ?crit : > > Eric Dumazet wrote: > > > Le dimanche 15 aou^t 2010 a` 12:55 +0200, Eric Dumazet a ?crit : > > ... > > > [PATCH] netfilter: {ip,ip6,arp}_tables: avoid lockdep false positive > > > > > > After commit 24b36f019 (netfilter: {ip,ip6,arp}_tables: dont block > > > bottom half more than necessary), lockdep can raise a warning > > > because we attempt to lock a spinlock with BH enabled, while > > > the same lock is usually locked by another cpu in a softirq context. > > > > Btw, could you remind us how get_counters() are serialized (I guess > > you can't have them on 2 cpus at the same time)? > > > > get_counters() is serialized by the xt_find_table_lock() done from > get_entries(). This use a mutex to guard against changes. > > You are right that if we ever allow two concurrent "iptables -nvL" > operations in the future (using a read lock on a rwlock instead of a > mutex), then we must disable BH even for summing data from the other > cpus. OK, thanks for the explanation, Jarek P. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/