From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.179]) by ozlabs.org (Postfix) with ESMTP id 22A08DDEDA for ; Tue, 19 Jun 2007 07:14:33 +1000 (EST) From: Arnd Bergmann To: linuxppc-dev@ozlabs.org Subject: Re: CONFIG_PS3_USE_LPAR_ADDR dramically increases boot time Date: Mon, 18 Jun 2007 23:14:26 +0200 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200706182314.26918.arnd@arndb.de> Cc: Jimi Xenidis List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Monday 18 June 2007, Jimi Xenidis wrote: >=20 > The following change set: > =A0 =A0http://git.kernel.org/?p=3Dlinux/kernel/git/paulus/=20 > powerpc.git;a=3Dcommit;h=3D261efc3f178c8c5b55d76208aee1f39ce247f723 >=20 > setting CONFIG_PS3_USE_LPAR_ADDR (which is the default for PS3) =A0 > changes increases MAX_PHYSADDR_BITS =A0from 44 to 47 which makes the =A0 > array 8 time bigger and takes way longer for sparse_init() to run on =A0 > simulator. >=20 > Is this really the right approach? > Cell is actually 42 so could not the special address space be 43 or 44? Unfortunately, the hypervisor chooses the addresses where things get mapped, and since they are guest-real, there is no hard limit where the hypervisor puts them, like the 42 bit limit on bare metal. I guess this will improve if we get virt_mem_map support on powerpc, but I'm not sure if that's currently being worked on. Arnd <><