From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758619AbYENWH4 (ORCPT ); Wed, 14 May 2008 18:07:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754093AbYENWHs (ORCPT ); Wed, 14 May 2008 18:07:48 -0400 Received: from vena.lwn.net ([206.168.112.25]:56677 "EHLO vena.lwn.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752349AbYENWHr (ORCPT ); Wed, 14 May 2008 18:07:47 -0400 To: Linus Torvalds cc: Ingo Molnar , Andrew Morton , Peter Zijlstra , Thomas Gleixner , Alan Cox , Alexander Viro , linux-kernel@vger.kernel.org Subject: Re: [announce] "kill the Big Kernel Lock (BKL)" tree From: corbet@lwn.net (Jonathan Corbet) In-reply-to: Your message of "Wed, 14 May 2008 14:56:37 PDT." Date: Wed, 14 May 2008 16:07:47 -0600 Message-ID: <7207.1210802867@vena.lwn.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > I don't think there are *that* many. I found only 83 instances of > "register_chrdev()" in the kernel, so the open methods should be pretty > limited. There's the drivers calling cdev_add() directly as well - another 40ish. Still not a huge list, I guess. > So it literally should be: > - remove one lock_kernel/unlock_kernel pair in fs/char_dev.c > - add max 83 pairs in the places that register those things > - external modules will need to add it themselves some day. This is all certainly doable, but it leaves me with one concern: there will be no signal to external module maintainers that the change needs to be made. So, beyond doubt, quite a few of them will just continue to be shipped unfixed - and they will still run. If any of them actually *need* the BKL, something awful may happen to somebody someday. jon