From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 13/16] powerpc: add ps3 platform lpar addressing From: Michael Ellerman To: Benjamin Herrenschmidt In-Reply-To: <1163292316.4982.240.camel@localhost.localdomain> References: <4554DB14.3070900@am.sony.com> <20061111112847.GD24288@lst.de> <1163292316.4982.240.camel@localhost.localdomain> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-94KzXEJ0dVh57jGbzEQU" Date: Mon, 13 Nov 2006 11:41:54 +1100 Message-Id: <1163378514.7410.16.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Paul Mackerras Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-94KzXEJ0dVh57jGbzEQU Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Sun, 2006-11-12 at 11:45 +1100, Benjamin Herrenschmidt wrote: > On Sat, 2006-11-11 at 12:28 +0100, Christoph Hellwig wrote: > > On Fri, Nov 10, 2006 at 12:03:32PM -0800, Geoff Levand wrote: > > > Adds some needed bits for a config option PS3PF_USE_LPAR_ADDR that di= sables > > > the ps3pf lpar address translation mechanism. This is a currently ne= eded > > > workaround for limitations in the design of the spu support. > >=20 > > So make the code do the sane thing and don't put the config in the > > kernel tree. >=20 > Well... I'd like to keep the option for a little while. >=20 > There are performances issues with sparsemem the way it's used by > ps3pf.. the problem is that the memory map looks like you get a bunch of > memory at 0 (the RMO, not sure exactly how much in practice) and the > rest in a chunk all the way up the 48 bits or so max physical space. >=20 > So sparsemem ends up with an enormous mapping only populated at the very > beginning and the very end. >=20 > Thus, I'd like Geoff to keep the option of doing the manual translation > in the hash code for now until I finally get some HW and thus can do > some measurements, and possibly figure out a nicer way to deal with > that. I haven't read the ps3 code very carefully, but at first glance it struck me that it has a similar problem to iSeries. It might be worth seeing if the iSeries mschunks_map gunk can help (see include/asm-powerpc/abs_addr.h) cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-94KzXEJ0dVh57jGbzEQU Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) iD8DBQBFV79SdSjSd0sB4dIRAmDPAKC4Kg8sL3D+FvpzhqgroSVjd1cMMACfSyrj 9hm9jg1Iy/Qt8vXXnoUlnFc= =2ER3 -----END PGP SIGNATURE----- --=-94KzXEJ0dVh57jGbzEQU--