From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753852Ab1AZATF (ORCPT ); Tue, 25 Jan 2011 19:19:05 -0500 Received: from mga02.intel.com ([134.134.136.20]:46479 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752707Ab1AZATE (ORCPT ); Tue, 25 Jan 2011 19:19:04 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.60,377,1291622400"; d="scan'208";a="596462999" From: Andi Kleen To: arnd@arndb.de Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/20] hpfs: replace BKL with a global mutex In-Reply-To: <1295993854-4971-11-git-send-email-arnd@arndb.de> (Arnd Bergmann's message of "Tue, 25 Jan 2011 23:17:24 +0100") References: <1295993854-4971-1-git-send-email-arnd@arndb.de> <1295993854-4971-11-git-send-email-arnd@arndb.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) Cancel-Lock: sha1:cl7TDsgqLfqlaIQ8OVB4pEoFwr8= Date: Tue, 25 Jan 2011 16:19:09 -0800 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Arnd Bergmann writes: > This removes the BKL in hpfs in a rather awful > way, by replacing it with a mutex that basically > serializes the entire file system. I don't think that's a very good idea, there's danger of holding it over IO and that would be really bad (as in like MINIX[1]) It would be better to do it the i810 way and check for the number of CPUs at module init time and refuse to run if it's > 1 -Andi [1] showing my age -- Andi Kleen Intel Open Source Technology Center