From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756111AbYHSQq3 (ORCPT ); Tue, 19 Aug 2008 12:46:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750921AbYHSQqT (ORCPT ); Tue, 19 Aug 2008 12:46:19 -0400 Received: from home.keithp.com ([63.227.221.253]:4901 "EHLO keithp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753448AbYHSQqS (ORCPT ); Tue, 19 Aug 2008 12:46:18 -0400 Subject: Re: [PATCH] Export shmem_file_setup and shmem_getpage for DRM-GEM From: Keith Packard To: Nick Piggin Cc: keithp@keithp.com, Dave Airlie , Christoph Hellwig , Eric Anholt , linux-kernel@vger.kernel.org In-Reply-To: <200808192000.47070.nickpiggin@yahoo.com.au> References: <1217573919-7496-1-git-send-email-eric@anholt.net> <200808051443.11858.nickpiggin@yahoo.com.au> <21d7e9970808181817n1d67dc33s58b8d07f63e411a7@mail.gmail.com> <200808192000.47070.nickpiggin@yahoo.com.au> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-Itdh3o6WO2JIJOdc7m+q" Date: Tue, 19 Aug 2008 09:46:07 -0700 Message-Id: <1219164367.10772.420.camel@koto.keithp.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-Itdh3o6WO2JIJOdc7m+q Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2008-08-19 at 20:00 +1000, Nick Piggin wrote: > Not exactly sure what you mean by this. But I would like to see an effort > made to use existing userspace APIs in order to do this swappable object > allocation over tmpfs scheme. As I said, I don't object to a nice kernel > implementation, but we would be in a much better position to assess it if > we had an existing userspace implementation to compare it with. We need to allocate objects from kernel mode to get the console running. I'd prefer to let that occur before user mode was available. Also, emulating the existing fbdev syscall interface will require that we allocate objects within the kernel. Hence, the question about how we should create objects from kernel mode. I think we can do this with a series of VFS function calls. Would that series of VFS calls be preferable to directly accessing the existing shmem API? Another alternative is to improve the existing shmem API to better capture what we're trying to do here. Both drm and sysv shm just want anonymous pages that are backed by swap. If we started from scratch, what API would we like to have here? Would we have it support both shmem and hugetlbfs? --=20 keith.packard@intel.com --=-Itdh3o6WO2JIJOdc7m+q Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iD8DBQBIqvjPQp8BWwlsTdMRAliNAKCjkpsiQDdTR3XXklB8fV9G8mXsKACgt4w5 2LUd+Lue9ae8AaBtn7ivgJQ= =aSr4 -----END PGP SIGNATURE----- --=-Itdh3o6WO2JIJOdc7m+q--