Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755445AbXJ3OSd (ORCPT ); Tue, 30 Oct 2007 10:18:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753303AbXJ3OSY (ORCPT ); Tue, 30 Oct 2007 10:18:24 -0400 Received: from gate.crashing.org ([63.228.1.57]:52521 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752608AbXJ3OSX (ORCPT ); Tue, 30 Oct 2007 10:18:23 -0400 In-Reply-To: <20071030083719.GJ32359@parisc-linux.org> References: <20071028201549.GA23138@fattire.cabal.ca> <20071030024801.GA19417@linux-mips.org> <20071030083719.GJ32359@parisc-linux.org> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Cc: Ralf Baechle , Kyle McMartin , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit From: Kumar Gala Subject: Re: [PATCH] Only show RESOURCES_64BIT on relevant architectures Date: Tue, 30 Oct 2007 09:19:31 -0500 To: Matthew Wilcox X-Mailer: Apple Mail (2.752.2) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 842 Lines: 21 On Oct 30, 2007, at 3:37 AM, Matthew Wilcox wrote: > On Mon, Oct 29, 2007 at 10:03:16PM -0500, Kumar Gala wrote: >> The same is true on PPC32. Its a per platform thing. However, I'm >> not sure if we could hide it from the user. There are cases on the >> same HW platform that you want to run with just 32-bit phys (for >> performance). > > Have you measured what the performance difference is? I have not. On some PPC32 systems having proper 36-bit physical support usually means growing our pte to be 64-bits which creates additional overhead in SW TLB mgmt on these processors. - k - 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/