From: Brad Campbell <brad@wasp.net.au>
To: Sau Dan Lee <danlee@informatik.uni-freiburg.de>
Cc: Vojtech Pavlik <vojtech@suse.cz>,
Giuseppe Bilotta <bilotta78@hotpop.com>,
linux-kernel@vger.kernel.org,
Tuukka Toivonen <tuukkat@ee.oulu.fi>
Subject: Re: keyboard problem with 2.6.6
Date: Sun, 30 May 2004 15:40:06 +0400 [thread overview]
Message-ID: <40B9C816.5090905@wasp.net.au> (raw)
In-Reply-To: <xb765aeb1i3.fsf@savona.informatik.uni-freiburg.de>
Sau Dan Lee wrote:
>
> Once in kernel space, forever in kernel space? What's the logic?
>
> Where it is now possible to move it out of kernel space WITHOUT
> performance problems, why not move it out?
I'd just like to comment on this particular point.
One application I have used utilises the keyboard as a trigger for audio processing and lighting
control. Having the keyboard processed in the kernel gives me pretty precise timing and low latency.
(Think setting CUE points in audio tracks. 10ms matters!). I'm not going to get that with a
userspace keyboard driver. Timing is still a little jittery, but then Linux is not a RTOS, but with
the driver in userspace I'm going to get a whole lot worse response for input events.
If you want to move the keyboard processing in userspace, why not just start with a microkernel.
There has to be a kernel/user line somewhere, and the grey areas are always going to be subject to
discussion.
Brad
next prev parent reply other threads:[~2004-05-30 11:40 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-07 20:55 [PATCH] SERIO_USERDEV: direct userspace access to mouse/keyboard psaux serial ports Tuukka Toivonen
2004-05-08 2:35 ` Andrew Morton
2004-05-25 20:16 ` keyboard problem with 2.6.6 Chris Osicki
2004-05-26 7:54 ` Sau Dan Lee
2004-05-28 13:33 ` Giuseppe Bilotta
2004-05-28 17:37 ` Sau Dan Lee
2004-05-29 13:12 ` Vojtech Pavlik
2004-05-30 9:45 ` Sau Dan Lee
2004-05-30 10:19 ` Vojtech Pavlik
2004-05-30 11:25 ` Sau Dan Lee
2004-05-30 11:40 ` Brad Campbell [this message]
2004-05-30 12:01 ` Oliver Neukum
2004-05-30 12:22 ` Sau Dan Lee
2004-05-30 12:32 ` Oliver Neukum
2004-05-30 12:16 ` Vojtech Pavlik
2004-05-30 12:40 ` Sau Dan Lee
2004-05-30 12:52 ` Vojtech Pavlik
2004-05-30 16:09 ` Stefan Seyfried
2004-05-30 17:26 ` Dmitry Torokhov
2004-06-04 13:58 ` Pavel Machek
2004-06-04 18:17 ` Horst von Brand
2004-06-04 18:37 ` Valdis.Kletnieks
2004-06-04 19:33 ` Denis Vlasenko
2004-06-04 19:50 ` Valdis.Kletnieks
2004-06-04 20:48 ` Denis Vlasenko
2004-06-04 18:39 ` Pavel Machek
2004-06-04 18:46 ` Sau Dan Lee
2004-06-04 19:09 ` Pavel Machek
2004-06-06 9:01 ` Sau Dan Lee
2004-06-06 16:40 ` Pavel Machek
2004-05-28 19:39 ` 2.6.* useland replacements of the atkbd and psmouse modules Sau Dan Lee
2004-05-28 19:57 ` keyboard problem with 2.6.6 Andries Brouwer
2004-06-01 8:21 ` BUG: atkbd.c keyboard driver bug [Was: keyboard problem with 2.6.6] Sau Dan Lee
2004-06-01 9:13 ` BUG FIX: " Sau Dan Lee
[not found] ` <200406010904.i5194pSo010367@fire-2.osdl.org>
2004-06-01 9:44 ` Sau Dan Lee
2004-06-01 9:55 ` Vojtech Pavlik
2004-06-01 10:03 ` Sau Dan Lee
2004-06-01 12:42 ` Giuseppe Bilotta
2004-05-28 19:41 ` keyboard problem with 2.6.6 Andries Brouwer
2004-05-28 20:10 ` Andries Brouwer
[not found] ` <20040528214620.GA2352@gucio>
2004-05-29 13:23 ` Andries Brouwer
2004-05-29 13:46 ` Vojtech Pavlik
2004-05-29 14:30 ` Andries Brouwer
2004-05-29 14:41 ` Vojtech Pavlik
2004-05-29 15:12 ` Giuseppe Bilotta
[not found] <xb7oenxyqly.fsf@savona.informatik.uni-freiburg.de>
[not found] ` <200406071551.i57Fpl89023562@turing-police.cc.vt.edu>
[not found] ` <xb7zn7fwdia.fsf@savona.informatik.uni-freiburg.de>
[not found] ` <200406071636.i57Gafh7024942@turing-police.cc.vt.edu>
[not found] ` <xb7r7sqwncc.fsf@savona.informatik.uni-freiburg.de>
[not found] ` <200406081502.i58F2gF3013622@turing-police.cc.vt.edu>
2004-06-09 8:17 ` Sau Dan Lee
2004-06-09 16:56 ` Valdis.Kletnieks
2004-06-09 17:12 ` Sau Dan Lee
2004-06-09 17:29 ` Valdis.Kletnieks
-- strict thread matches above, loose matches on Subject: below --
2004-06-06 9:43 Sau Dan Lee
2004-06-06 9:37 Sau Dan Lee
2004-06-06 11:29 ` Martin Schlemmer
2004-06-06 12:07 ` Vojtech Pavlik
2004-06-06 15:09 ` Dmitry Torokhov
2004-06-06 16:13 ` Sau Dan Lee
[not found] ` <200406061929.45169.vda@port.imtp.ilyichevsk.odessa.ua>
[not found] ` <200406061140.35929.dtor_core@ameritech.net>
2004-06-06 16:51 ` Sau Dan Lee
[not found] <xb7ekp2b34y.fsf@savona.informatik.uni-freiburg.de>
[not found] ` <20040530112138.GC1377@ucw.cz>
2004-05-30 11:43 ` Sau Dan Lee
2004-05-30 12:45 ` Vojtech Pavlik
2004-05-30 13:25 ` Sau Dan Lee
2004-05-30 10:57 Sau Dan Lee
2004-06-01 11:31 ` Pavel Machek
2004-06-01 14:06 ` John Bradford
2004-05-30 10:45 Sau Dan Lee
2004-05-30 11:20 ` Vojtech Pavlik
2004-05-30 10:39 Sau Dan Lee
2004-05-30 11:18 ` Vojtech Pavlik
2004-05-30 11:40 ` Sau Dan Lee
2004-05-30 11:53 ` Russell King
2004-05-30 12:43 ` Vojtech Pavlik
2004-05-30 13:25 ` Sau Dan Lee
2004-06-01 21:01 ` jsimmons
2004-06-01 21:12 ` Valdis.Kletnieks
2004-05-30 13:54 ` Eduard Bloch
2004-05-30 14:03 ` Vojtech Pavlik
2004-06-01 21:03 ` jsimmons
2004-06-04 14:11 ` Pavel Machek
2004-05-28 13:59 Tuukka Toivonen
2004-05-29 13:14 ` Vojtech Pavlik
2004-06-04 14:54 ` Tuukka Toivonen
2004-06-04 16:06 ` Vojtech Pavlik
[not found] <MPG.1b2111558bc2d299896a2@news.gmane.org.suse.lists.linux.kernel>
[not found] ` <20040525201616.GE6512@gucio.suse.lists.linux.kernel>
[not found] ` <xb7hdu3fwsj.fsf@savona.informatik.uni-freiburg.de.suse.lists.linux.kernel>
[not found] ` <xb7aczscv0q.fsf@savona.informatik.uni-freiburg.de.suse.lists.linux.kernel>
[not found] ` <20040529131233.GA6185@ucw.cz.suse.lists.linux.kernel>
[not found] ` <xb7y8nab65d.fsf@savona.informatik.uni-freiburg.de.suse.lists.linux.kernel>
[not found] ` <20040530101914.GA1226@ucw.cz.suse.lists.linux.kernel>
[not found] ` <xb765aeb1i3.fsf@savona.informatik.uni-freiburg.de.suse.lists.linux.kernel>
[not found] ` <20040530121606.GA1496@ucw.cz.suse.lists.linux.kernel>
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