From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964797AbWAWFiN (ORCPT ); Mon, 23 Jan 2006 00:38:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964802AbWAWFiN (ORCPT ); Mon, 23 Jan 2006 00:38:13 -0500 Received: from smtp.osdl.org ([65.172.181.4]:40675 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S964797AbWAWFiM (ORCPT ); Mon, 23 Jan 2006 00:38:12 -0500 Date: Sun, 22 Jan 2006 21:37:41 -0800 From: Andrew Morton To: Alasdair G Kergon Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/9] device-mapper log bitset: fix endian Message-Id: <20060122213741.7d2ed8ef.akpm@osdl.org> In-Reply-To: <20060120211300.GC4724@agk.surrey.redhat.com> References: <20060120211300.GC4724@agk.surrey.redhat.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alasdair G Kergon wrote: > > - set_bit(bit, (unsigned long *) bs); > + ext2_set_bit(bit, (unsigned long *) bs); We really should give those things a more appropriate name. ext2_set_bit() is non-atomic, so the above code must provide its own locking against other CPUs (and threads, if preempt) performing modification of this memory. Is such locking present? If not, we should use ext2_set_bit_atomic(). (And if so, the old code could have used __set_bit)