From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: RFC: x86: cap iomem_resource to addressable physical memory Date: Mon, 22 Jun 2009 00:54:14 -0700 Message-ID: <4A3F38A6.80906@linux.intel.com> References: <4A2F0D45.2040602@linux.intel.com> <86802c440906111343g513a2ceau1e2bfdf14c295b2d@mail.gmail.com> <4A316D3C.7080403@linux.intel.com> <20090621064201.GD1656@ucw.cz> <4A3DE3F3.4000100@linux.intel.com> <20090621205534.GA4324@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090621205534.GA4324@elf.ucw.cz> Sender: linux-pci-owner@vger.kernel.org To: Pavel Machek Cc: Yinghai Lu , Matthew Wilcox , Jesse Barnes , Martin Mares , LKML , linux-pci@vger.kernel.org, the arch/x86 maintainers , David Woodhouse , linux-arch@vger.kernel.org List-Id: linux-arch.vger.kernel.org Pavel Machek wrote: > > Ok... and is there enough locking in there so that it is actually ok > to change mask during hotplug? (Is it okay because it is single long > and all the writers are somehow serialized by hotplug mechanism?) > Pavel Making it a locked reference probably would be a good idea (although I personally think it will never actually matter in practice). Although on 32 bits (PAE) it can be more than one long, it doesn't matter because only the upper long can actually be modified. It does, however, complicate the actual code somewhat... I'll look at it tomorrow. -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com ([134.134.136.24]:12212 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752374AbZFVHyM (ORCPT ); Mon, 22 Jun 2009 03:54:12 -0400 Message-ID: <4A3F38A6.80906@linux.intel.com> Date: Mon, 22 Jun 2009 00:54:14 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: RFC: x86: cap iomem_resource to addressable physical memory References: <4A2F0D45.2040602@linux.intel.com> <86802c440906111343g513a2ceau1e2bfdf14c295b2d@mail.gmail.com> <4A316D3C.7080403@linux.intel.com> <20090621064201.GD1656@ucw.cz> <4A3DE3F3.4000100@linux.intel.com> <20090621205534.GA4324@elf.ucw.cz> In-Reply-To: <20090621205534.GA4324@elf.ucw.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Pavel Machek Cc: Yinghai Lu , Matthew Wilcox , Jesse Barnes , Martin Mares , LKML , linux-pci@vger.kernel.org, the arch/x86 maintainers , David Woodhouse , linux-arch@vger.kernel.org Message-ID: <20090622075414.9bI82D-BJtXqGnv8sp41aaZb-xUL5i1iWSy2EliGa_c@z> Pavel Machek wrote: > > Ok... and is there enough locking in there so that it is actually ok > to change mask during hotplug? (Is it okay because it is single long > and all the writers are somehow serialized by hotplug mechanism?) > Pavel Making it a locked reference probably would be a good idea (although I personally think it will never actually matter in practice). Although on 32 bits (PAE) it can be more than one long, it doesn't matter because only the upper long can actually be modified. It does, however, complicate the actual code somewhat... I'll look at it tomorrow. -hpa