Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756476AbXJZEdA (ORCPT ); Fri, 26 Oct 2007 00:33:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750875AbXJZEcx (ORCPT ); Fri, 26 Oct 2007 00:32:53 -0400 Received: from gate.crashing.org ([63.228.1.57]:34331 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834AbXJZEcw (ORCPT ); Fri, 26 Oct 2007 00:32:52 -0400 Subject: Re: [interesting] smattering of possible memory ordering bugs From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Nick Piggin Cc: Linux Kernel Mailing List , paulus@samba.org, shaggy@austin.ibm.com, adaplas@gmail.com, "Morton, Andrew" , xfs-masters@oss.sgi.com In-Reply-To: <200710261347.35545.nickpiggin@yahoo.com.au> References: <200710261209.58519.nickpiggin@yahoo.com.au> <1193369717.7018.56.camel@pasglop> <200710261347.35545.nickpiggin@yahoo.com.au> Content-Type: text/plain Date: Fri, 26 Oct 2007 14:32:27 +1000 Message-Id: <1193373147.7018.70.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 719 Lines: 23 On Fri, 2007-10-26 at 13:47 +1000, Nick Piggin wrote: > I don't think the previous code was wrong... it's not a locked section > > and we don't care about ordering previous stores. It's an > allocation, it > > should be fine. In general, bitmap allocators should be allright. > > Well if it is just allocating an arbitrary _number_ out of a bitmap > and nothing else (eg. like the pid allocator), then you don't need > barriers. Yup, that's what it does. Cheers, Ben. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/