From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Bunk Date: Wed, 08 Feb 2006 02:08:32 +0000 Subject: Re: [2.6 patch] let IA64_GENERIC select more stuff Message-Id: <20060208020832.GK3524@stusta.de> List-Id: References: <20060208011938.GJ3524@stusta.de> <200602080140.k181eDg20764@unix-os.sc.intel.com> In-Reply-To: <200602080140.k181eDg20764@unix-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Chen, Kenneth W" Cc: Keith Owens , "Luck, Tony" , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, Feb 07, 2006 at 05:40:13PM -0800, Chen, Kenneth W wrote: > Adrian Bunk wrote on Tuesday, February 07, 2006 5:20 PM > > You could ask the same question for NUMA: > > Select generic system type does not mean NUMA systems are only choice I > > can have. What's wrong with having an option that works just fine? > > Please read more ia64 arch specific code ... > > CONFIG_IA64_GENERIC is a platform type choice, you can have platform > type of DIG, HPZX1, SGI SN2, or all of the above. DIG platform depends > on ACPI, thus need ACPI on. SGI altix is a numa box, thus, need NUMA > on. NEC, Fujitsu build numa machines with ACPI SRAT table, thus, need > ACPI_NUMA on. When you build a kernel to boot on all platforms, you > have no choice but to turn on all of the above. Processor type and SMP > is different from platform type. It does not have any dependency on > platform type. They are orthogonal choice. This is interesting, considering that e.g. IA64_SGI_SN2=y, NUMA=n or IA64_DIG=y, ACPI=n are currently allowed configurations. > > Keith said IA64_GENERIC should select all the options required in > > order to run on all the IA64 platforms out there. > ^^^^^^^^^^^^^^ > > This is what my patch does. > > You patch does more than what you described and is wrong. Selecting > platform type should not be tied into selecting SMP nor should it tied This was what Keith wanted. It seems everyone thinks I am wrong, but when I'm implementing what one person suggests, other people say that what I am doing is wrong. > with processor type, nor should it tied with ARCH_FLATMEM_ENABLE. All > of them are orthogonal and independent. 1. NUMA on ia64 currently depends on !FLATMEM. 2. IA64_GENERIC currently select's NUMA. 3. You say IA64_GENERIC should not be tied with ARCH_FLATMEM_ENABLE. It's impossible to fulfill all three of them. My initial approach to fix them was to remove the select's from IA64_GENERIC, therefore removing 2., but this patch was not accepted. This patch adds more select's to IA64_GENERIC, therefore removing 3., but you disagree with it. The last choice it to remove the dependency of NUMA on !FLATMEM... ;-) > Theoretically and maybe academically interesting, I should be able to > build a kernel that boots on all UP platforms, with your patch, that > is not possible. Theoretically and maybe academically interesting, I should be able to build a kernel that boots on all non-NUMA platforms, currently, that is not possible. > - Ken cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed