From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 24E76DDF33 for ; Mon, 8 Oct 2007 23:31:30 +1000 (EST) In-Reply-To: <1191791123.6392.0.camel@pasglop> References: <18184.23379.478676.911097@cargo.ozlabs.ibm.com> <796C20BF-1592-4F07-B83B-5EA35CADBA01@kernel.crashing.org> <1191791123.6392.0.camel@pasglop> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <94E2E7A0-FFCA-4F08-9A9C-AA62CAE63F63@kernel.crashing.org> From: Kumar Gala Subject: Re: TASK_SIZE default 0x80000000 ? Date: Mon, 8 Oct 2007 08:31:40 -0500 To: benh@au1.ibm.com Cc: PowerPC dev list , Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Oct 7, 2007, at 4:05 PM, Benjamin Herrenschmidt wrote: > >> Can you explain (a) further -- I'm assuming the BAT mapping is 1:1 >> for that region? >> >> For (b) it looks like: >> * 40x, 44x, fsl-booke compare against TASK_SIZE in their software >> handlers. >> * 8xx still tests 0x80000000 >> * 6xx (603) compares against KERNELBASE >> >> It would seem like we should set the default on 8xx & PReP to >> 0x80000000 and not allow it to be modified since that will break the >> world and for everything else move it to match KERNELBASE. Any >> issues with that? > > The proper value is neither :-) > > It should be compared against PAGE_OFFSET. I'll work up a patch to switch us to testing PAGE_OFFSET instead. - k