From: Ingo Molnar <mingo@elte.hu>
To: Keith Packard <keithp@keithp.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Dave Airlie <airlied@linux.ie>, Yinghai Lu <yinghai@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
dri-devel@lists.sf.net, Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: io resources and cached mappings (was: [git pull] drm patches for 2.6.27-rc1)
Date: Mon, 20 Oct 2008 13:58:10 +0200 [thread overview]
Message-ID: <20081020115810.GC10594@elte.hu> (raw)
In-Reply-To: <1224450291.5303.23.camel@koto.keithp.com>
* Keith Packard <keithp@keithp.com> wrote:
> On Sun, 2008-10-19 at 19:53 +0200, Ingo Molnar wrote:
>
> > Note how simple and consistent it all gets: IO resources already
> > know their physical location and their size limits. Being able to
> > cache an ioremap in a mapping [and being able to use atomic kmaps on
> > 32-bit] is a relatively simple and natural extension to the concept.
>
> I'm not sure I see any value in caching mappings here; we're mostly
> interested in copying lots of data onto the card and so we use a lot
> of different mappings; atomic mappings are easy to use, and efficient
> enough.
yes but note that by caching the whole mapping on 64-bit we get
everything we want: trivially lockless, works from any CPU, can be
preempted at will, and there are no ugly INVLPG flushes anywhere.
you'll even get 2MB mappings automatically, if the BAR is aligned and
sized correctly.
32-bit we should handle as well but not design for it.
Ingo
next prev parent reply other threads:[~2008-10-20 11:58 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-17 21:29 [git pull] drm patches for 2.6.27-rc1 Dave Airlie
2008-10-17 22:43 ` Linus Torvalds
2008-10-18 2:10 ` Eric Anholt
2008-10-18 2:47 ` Linus Torvalds
2008-10-18 3:49 ` Keith Packard
2008-10-18 6:44 ` Corbin Simpson
2008-10-18 7:49 ` Eric Anholt
2008-10-19 17:52 ` Peter Zijlstra
2008-10-20 4:17 ` Steven J Newbury
2008-10-20 16:31 ` Linus Torvalds
2008-10-20 20:04 ` Jesse Barnes
2008-10-18 9:11 ` Dave Airlie
2008-10-18 1:37 ` Nick Piggin
2008-10-18 19:11 ` Keith Packard
2008-10-18 19:31 ` Linus Torvalds
2008-10-18 20:07 ` Thomas Hellström
2008-10-18 20:20 ` Keith Packard
2008-10-18 20:37 ` Ingo Molnar
2008-10-18 21:51 ` Keith Packard
2008-10-18 22:32 ` Ingo Molnar
2008-10-18 22:47 ` Jon Smirl
2008-10-18 22:53 ` Linus Torvalds
2008-10-19 0:38 ` Keith Packard
2008-10-19 1:06 ` Arjan van de Ven
2008-10-19 1:15 ` Keith Packard
2008-10-20 10:01 ` Ingo Molnar
2008-10-19 4:14 ` Keith Packard
2008-10-19 6:41 ` Keith Packard
2008-10-19 17:53 ` io resources and cached mappings (was: [git pull] drm patches for 2.6.27-rc1) Ingo Molnar
2008-10-19 18:00 ` Arjan van de Ven
2008-10-19 19:07 ` Eric Anholt
2008-10-20 11:55 ` Ingo Molnar
2008-10-20 12:20 ` Ingo Molnar
2008-10-19 21:04 ` Keith Packard
2008-10-20 11:58 ` Ingo Molnar [this message]
2008-10-20 15:49 ` Keith Packard
2008-10-22 9:36 ` Ingo Molnar
2008-10-23 7:14 ` Keith Packard
2008-10-23 7:14 ` [PATCH] Add io-mapping functions to dynamically map large device apertures Keith Packard
2008-10-23 7:14 ` [PATCH] [drm/i915] Use io-mapping interfaces instead of a variety of mapping kludges Keith Packard
2008-10-24 4:49 ` [PATCH] Add io-mapping functions to dynamically map large device apertures Randy Dunlap
2008-10-24 6:26 ` Keith Packard
2008-10-23 8:05 ` io resources and cached mappings (was: [git pull] drm patches for 2.6.27-rc1) Ingo Molnar
2008-10-23 15:39 ` Keith Packard
2008-11-03 7:00 ` Dave Airlie
2008-11-03 10:48 ` Ingo Molnar
2008-11-03 16:36 ` Linus Torvalds
2008-11-03 16:53 ` Ingo Molnar
2008-11-03 17:29 ` [git pull] IO mappings, #2 Ingo Molnar
2008-11-04 22:36 ` Jonathan Corbet
2008-11-05 9:01 ` Ingo Molnar
2008-10-23 20:22 ` Adding kmap_atomic_prot_pfn (was: [git pull] drm patches for 2.6.27-rc1) Keith Packard
2008-10-23 20:38 ` Andrew Morton
2008-10-23 21:03 ` Keith Packard
2008-10-23 21:24 ` Linus Torvalds
2008-10-24 1:50 ` Keith Packard
2008-10-24 2:48 ` Linus Torvalds
2008-10-24 3:24 ` Benjamin Herrenschmidt
2008-10-24 5:37 ` Keith Packard
2008-10-24 14:53 ` Linus Torvalds
2008-10-24 15:45 ` Keith Packard
2008-10-24 4:29 ` Keith Packard
2008-10-24 6:22 ` Keith Packard
2008-10-24 7:33 ` Adding kmap_atomic_prot_pfn Thomas Hellström
2008-10-24 8:38 ` Ingo Molnar
2008-10-24 9:19 ` Thomas Hellström
2008-10-24 9:32 ` Ingo Molnar
2008-10-24 11:04 ` Thomas Hellström
2008-10-24 15:48 ` Keith Packard
2008-10-24 10:18 ` Thomas Hellström
2008-10-24 9:14 ` Adding kmap_atomic_prot_pfn (was: [git pull] drm patches for 2.6.27-rc1) Ingo Molnar
2008-10-24 3:21 ` Benjamin Herrenschmidt
2008-10-20 10:10 ` io resources and cached mappings " Ingo Molnar
2008-10-19 4:28 ` [git pull] drm patches for 2.6.27-rc1 Yinghai Lu
2008-10-19 3:14 ` Nick Piggin
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