From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754673Ab1FJJeH (ORCPT ); Fri, 10 Jun 2011 05:34:07 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:33637 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750774Ab1FJJeF (ORCPT ); Fri, 10 Jun 2011 05:34:05 -0400 Date: Fri, 10 Jun 2011 11:33:54 +0200 From: Ingo Molnar To: Andrew Morton Cc: Hugh Dickins , Peter Zijlstra , Linus Torvalds , Thomas Gleixner , linux-kernel@vger.kernel.org, efault@gmx.de, Arne Jansen Subject: Re: [PATCH 1/3] printk: Release console_sem after logbuf_lock Message-ID: <20110610093354.GH27280@elte.hu> References: <20110609130647.937204592@chello.nl> <20110609131307.493181962@chello.nl> <20110609130617.f8aca966.akpm@linux-foundation.org> <20110609202707.GA28951@elte.hu> <1307652883.2497.1028.camel@laptop> <20110609140714.fc9ea187.akpm@linux-foundation.org> <20110609170804.1b76e853.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110609170804.1b76e853.akpm@linux-foundation.org> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Morton wrote: > > Some notes: > > Stupid thing doesn't explain the magical locking though :( I'm > 99.9% sure that putting an up() inside a spinlock_irq()ed region > was deliberate. My guess would be it's done so that pending irqs that have queued up during our current printk-ing activities do not hit us with the console still locked. Thanks, Ingo