From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762751AbYFQXMa (ORCPT ); Tue, 17 Jun 2008 19:12:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762272AbYFQXIk (ORCPT ); Tue, 17 Jun 2008 19:08:40 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:51473 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1762269AbYFQXIj (ORCPT ); Tue, 17 Jun 2008 19:08:39 -0400 Date: Tue, 17 Jun 2008 16:08:39 -0700 (PDT) Message-Id: <20080617.160839.112511197.davem@davemloft.net> To: johannes@sipsolutions.net Cc: linux-kernel@vger.kernel.org, mb@bu3sch.de, david@identd.dyndns.org, linux-wireless@vger.kernel.org, mingo@elte.hu, torvalds@linux-foundation.org Subject: Re: [PATCH/RFC] remove irqs_disabled warning from local_bh_enable From: David Miller In-Reply-To: <1213739834.3803.137.camel@johannes.berg> References: <1213739834.3803.137.camel@johannes.berg> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Berg Date: Tue, 17 Jun 2008 23:57:14 +0200 > This warning has started to trigger with mac80211 because it can, under > some circumstances, use spin_lock_bh() protected sections within > irq-disabled sections. Is that a bug? It is a bug. The only legal nesting is base --> BH --> IRQ locking. > Also, if you're going to treat IRQs being enabled as a bug, there's no > point in disabling them right afterwards, is there? It's treating IRQs being "disabled" as a bug. It expects them to be enabled, always. > If you're going to reject this patch, I'll post one that adds the > warning to local_bh_enable_ip() to allow detecting this for everybody > and not just those poor people running UP/NO-PREEMPT :) That might be useful :)