From: Ingo Molnar <mingo@elte.hu>
To: Eric Anholt <eric@anholt.net>
Cc: Keith Packard <keithp@keithp.com>,
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>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: io resources and cached mappings (was: [git pull] drm patches for 2.6.27-rc1)
Date: Mon, 20 Oct 2008 14:20:46 +0200 [thread overview]
Message-ID: <20081020122046.GA25152@elte.hu> (raw)
In-Reply-To: <20081020115533.GB10594@elte.hu>
* Ingo Molnar <mingo@elte.hu> wrote:
> that gets ugly very fast. I think we should not use atomic kmaps but
> NR_CPUS _fixmaps_ with a per CPU array of mutexes (this is basically
> atomic kmaps but without the preemption restrictions). We could
> take/drop the mutex and statistically you'll stay on the same CPU and
> wont ever contend on that lock in practice.
peterz pointed it out that we need to be careful with the TLBs in that
case.
I think it's solvable: a small non-default special-case in switch_to()
would invlpg any pending such page. (and no two such mappings could be
held at the same time)
So as long as we dont leave the CPU we wont ever do TLB flushes, and the
flush will be local even if we do.
Ingo
next prev parent reply other threads:[~2008-10-20 12:21 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 [this message]
2008-10-19 21:04 ` Keith Packard
2008-10-20 11:58 ` Ingo Molnar
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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