From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755823Ab0ENW7T (ORCPT ); Fri, 14 May 2010 18:59:19 -0400 Received: from relay3.sgi.com ([192.48.152.1]:37008 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752861Ab0ENW7R (ORCPT ); Fri, 14 May 2010 18:59:17 -0400 Message-ID: <4BEDD5BF.5030005@sgi.com> Date: Fri, 14 May 2010 15:59:11 -0700 From: Mike Travis User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Jesse Barnes CC: Bjorn Helgaas , Mike Habeck , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, Jacob Pan , Tejun Heo , LKML , Yinghai , "linux-pci@vger.kernel.org" , Myron Stowe Subject: Re: [Patch 1/1] x86 pci: Add option to not assign BAR's if not already assigned References: <4BEAF008.9030805@sgi.com> <201005131256.17997.bjorn.helgaas@hp.com> <4BEC5530.1000008@sgi.com> <201005131402.30759.bjorn.helgaas@hp.com> <20100514152509.3aeb37b4@virtuousgeek.org> <4BEDCFD9.7020202@sgi.com> <20100514154706.4f36f4ed@virtuousgeek.org> In-Reply-To: <20100514154706.4f36f4ed@virtuousgeek.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jesse Barnes wrote: > On Fri, 14 May 2010 15:34:01 -0700 > Mike Travis wrote: > >> >> Jesse Barnes wrote: >>> On Thu, 13 May 2010 14:02:30 -0600 >>> Bjorn Helgaas wrote: >>>>>> This issue is not specific to x86, so I don't really like having >>>>>> the implementation be x86-specific. >>>>> I agree this isn't a x86 specific issue but given the 'norom' >>>>> cmdline option is basically doing the same thing (but for pci >>>>> Expansion ROM BARs) this code was modeled after it. >>>> IMHO, we should fix both. >>> Yeah, that would be good. Mike, have you looked at this at all? >>> >>> Also, to clarify, this isn't affecting users today, right? Or do you >>> need all this I/O space for multiple IOHs and the drivers that bind to >>> them in current UV systems? >> We have customers that want to install more than 16 PCI-e cards right >> now. Our window of opportunity closes very soon (days), so either this >> patch makes it in as is (or something close), or we wait for another >> release cycle. UV shipments start this month. >> >> [I wouldn't mind working on an improvement for later.] > > Wow and they're using cards that want to use I/O space? Funky. It's > too late to get this into 2.6.34, but that can't be what you were > expecting... I don't see a problem with getting something like this in > for 2.6.35. 2.6.35 would be fine. It's the acceptance that's the key. And yes, we're using standard cards like everyone else... ;-) [The message is "UV" is just a really, really big PC. ;-)] I would appreciate however, some more detail on what's the goal of the updates to "fix both". Thanks! > >>> Fundamentally, until we have real dynamic PCI resource management (i.e. >>> driver hooks for handling relocation, lazy allocation of resources at >>> driver bind time, etc.) we're going to continue to need hacks like >>> this. However, we could make them slightly more automated by making >>> "nobar" and "norom" the default on systems that typically need them, >>> maybe with a DMI table. >> It seems that BIOS changes are much more difficult. The real solution >> to this problem is for Card Vendors to not request I/O Bars if they >> won't be using them. But that's the hardest option of all to accomplish. > > Right. >