From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jack Steiner Subject: Re: [RFC - V2] - Mapping ACPI tables as CACHED Date: Wed, 8 Dec 2010 15:22:44 -0600 Message-ID: <20101208212244.GA24280@sgi.com> References: <20100722152220.GA18290@sgi.com> <20100724001449.GA9618@khazad-dum.debian.net> <4C743C0F.2010101@zytor.com> <20100826171704.GA21584@sgi.com> <4C76AD82.2030105@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from relay3.sgi.com ([192.48.152.1]:35679 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750951Ab0LHVY1 (ORCPT ); Wed, 8 Dec 2010 16:24:27 -0500 Content-Disposition: inline In-Reply-To: <4C76AD82.2030105@zytor.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "H. Peter Anvin" , lenb@kernel.org Cc: hmh@hmh.eng.br, mingo@elte.hu, tglx@linutronix.de, tony.luck@gmail.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, gbeshers@sgi.com On Thu, Aug 26, 2010 at 11:08:02AM -0700, H. Peter Anvin wrote: > On 08/26/2010 10:17 AM, Jack Steiner wrote: > > Map ACPI tables as WB on x86_64. No substantive changes to IA64. > > > > > > Signed-off-by: Jack Steiner > > > > --- > > V2 - Change the patch to unconditionally map ACPI tables as WB on x86_64. > > I'm still some paranoid about this because of the potential imapct on > > some platforms with weird BIOSs. However, note that on EFI-enabled > > systems (like UV), the ACPI tables are already mapped as WB memory. > > This is done in the EFI function efi_enter_virtual_mode(). > > The ACPI code in acpi_os_map_memory() is not currently aware of the > > EFI mapping & currently maps the memory as UC. This seems like a bug. > > > > I really think that it's all a consequence of the fact that ioremap() > became implicitly UC when we added PAT support (being the more > conservative choice.) > > Len, want to take this one or should I? > > -hpa What is the upstream status of this patch? See the LKML discussion at: http://marc.info/?l=linux-kernel&m=128206079905826&w=2 http://marc.info/?l=linux-acpi&m=128284304032481&w=2 We would like to get this patch into the distros but need upstream acceptance first. This patch substantially reduces the time to run ACPIDUMP on a large system: 527 seconds without the patch 8 seconds with the patch Is there something I should be doing? I can resend the patch if needed. --- jack