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From: Pavel Machek <pavel@suse.cz>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Abramo Bagnara <abramo@alsa-project.org>
Cc: D.A.Fedorov@inp.nsk.su,
	Oliver Neukum <Oliver.Neukum@lrz.uni-muenchen.de>,
	Balbir Singh <balbir_soni@yahoo.com>,
	linux-kernel@vger.kernel.org
Subject: Re: Is it useful to support user level drivers
Date: Fri, 29 Jun 2001 00:57:30 +0200	[thread overview]
Message-ID: <20010629005730.I525@bug.ucw.cz> (raw)
In-Reply-To: <3B322224.91E17820@alsa-project.org> <E15D8Ec-0001lL-00@the-village.bc.nu>
In-Reply-To: <E15D8Ec-0001lL-00@the-village.bc.nu>; from Alan Cox on Thu, Jun 21, 2001 at 06:27:14PM +0100

Hi!

> > (i.e. counted). An alternative to queuing (user selectable) is to block
> > interrupt generation at hardware level in kernel space immediately
> > before notification.
> > 
> > I'm missing something?
> 
> IRQ 9 shared between user space app and disk. IRQ arrives is disabled and
> reported, app wakes up, app wants to page in code, IRQ is disabled,
> box dies

Actually, what about specifying that your usermode app has to be
pagelocked?

Alternatively.... You *can* do disk I/O without interrupts. Just poll
your IDE controller. [I'm doing that on my velo.] Hopefully your timer
IRQ is not shared with usermode app, then :-( [but that's almost
impossible on PCs, right?].
								Pavel
-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org

  parent reply	other threads:[~2001-06-29 18:02 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-06-21 10:41 Is it useful to support user level drivers Balbir Singh
2001-06-21 10:55 ` Tim Waugh
2001-06-21 11:04 ` Alan Cox
2001-06-21 12:43   ` Balbir Singh
2001-06-21 13:27     ` Alan Cox
2001-06-28 22:52     ` Pavel Machek
2001-06-21 12:45   ` Dmitry A. Fedorov
2001-06-21 13:24     ` Oliver Neukum
2001-06-21 14:46       ` Dmitry A. Fedorov
2001-06-21 15:19         ` Oliver Neukum
2001-06-22  4:19           ` Dmitry A. Fedorov
2001-06-22  7:28             ` Balbir Singh
2001-06-21 16:34         ` Abramo Bagnara
2001-06-21 17:27           ` Alan Cox
2001-06-21 19:59             ` Abramo Bagnara
2001-06-21 20:40               ` Richard B. Johnson
2001-06-21 20:54                 ` Abramo Bagnara
2001-06-21 21:09               ` Oliver Neukum
2001-06-28 22:57             ` Pavel Machek [this message]
2001-06-21 13:28     ` Alan Cox
2001-06-21 14:03       ` Matthias Urlichs
2001-06-28 22:54         ` Pavel Machek
2001-06-21 14:20       ` Dmitry A. Fedorov
2001-06-21 11:38 ` Dmitry A. Fedorov
2001-06-21 13:50   ` john slee
2001-06-21 13:58     ` Matthias Urlichs
2001-06-21 14:21       ` john slee
2001-06-28 22:51 ` Pavel Machek
     [not found] <mailman.993156181.18994.linux-kernel2news@redhat.com>
2001-06-21 22:06 ` Pete Zaitcev
2001-06-21 22:20   ` David S. Miller
2001-06-21 23:09     ` Mike Mackovitch
2001-06-21 23:22       ` David S. Miller
2001-06-21 23:50         ` Mike Mackovitch
2001-06-22  0:36           ` David S. Miller
2001-06-21 23:40   ` Richard B. Johnson
2001-06-22  0:30     ` Anders Larsen
2001-06-22  0:43       ` Richard B. Johnson
2001-06-25  0:06         ` Anders Larsen

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