From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751304AbWBWWmd (ORCPT ); Thu, 23 Feb 2006 17:42:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751774AbWBWWmd (ORCPT ); Thu, 23 Feb 2006 17:42:33 -0500 Received: from kanga.kvack.org ([66.96.29.28]:32650 "EHLO kanga.kvack.org") by vger.kernel.org with ESMTP id S1751304AbWBWWmd (ORCPT ); Thu, 23 Feb 2006 17:42:33 -0500 Date: Thu, 23 Feb 2006 17:37:29 -0500 From: Benjamin LaHaise To: Alan Stern Cc: Andrew Morton , sekharan@us.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Avoid calling down_read and down_write during startup Message-ID: <20060223223729.GE30329@kvack.org> References: <20060223110350.49c8b869.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 23, 2006 at 05:36:56PM -0500, Alan Stern wrote: > This patch (as660) changes the registration and unregistration routines > for blocking notifier chains. During system startup, when task switching > is illegal, the routines will avoid calling down_write(). Why is that necessary? The down_write() will immediately succeed as no other process can possibly be holding the lock when the system is booting, so the special casing doesn't fix anything. -ben -- "Ladies and gentlemen, I'm sorry to interrupt, but the police are here and they've asked us to stop the party." Don't Email: .