From: Abramo Bagnara <abramo@alsa-project.org>
To: Alexander Viro <viro@math.psu.edu>
Cc: Jeremy Elson <jelson@circlemud.org>,
Marcelo Tosatti <marcelo@conectiva.com.br>,
linux-kernel@vger.kernel.org
Subject: Re: Mapping a piece of one process' addrspace to another?
Date: Wed, 07 Mar 2001 10:20:11 +0100 [thread overview]
Message-ID: <3AA5FD4B.B2CE1AAF@alsa-project.org> (raw)
In-Reply-To: <Pine.GSO.4.21.0103070409410.2127-100000@weyl.math.psu.edu>
Alexander Viro wrote:
>
> On Wed, 7 Mar 2001, Abramo Bagnara wrote:
>
> > Alexander Viro wrote:
> > >
> > > On Wed, 7 Mar 2001, Jeremy Elson wrote:
> > >
> > > > Right now, my code looks something like this: (it might make more
> > > > sense if you know that I've written a framework for writing user-space
> > > > device drivers... I'm going to be releasing it soon, hopefully after I
> > > > resolve this performance problem. Or maybe before, if it's hard.)
> > >
> > > Ugh. Why not make that a named pipe and use zerocopy stuff for pipes?
> > > I.e. why bother with making it look like a character device rather than
> > > a FIFO?
> >
> > What about ioctl? Device drivers sometimes need it ;-)
>
> No, they don't. OOB data is equivalent to data on parallel channel.
Al, you're perfectly right in principle (although last time I've checked
pipe and unix socket did not support OOB data. Is this changed
recently?).
But you're forgetting that we need to cope with non collaborative
applications (that *use* ioctl).
--
Abramo Bagnara mailto:abramo@alsa-project.org
Opera Unica Phone: +39.546.656023
Via Emilia Interna, 140
48014 Castel Bolognese (RA) - Italy
ALSA project is http://www.alsa-project.org
sponsored by SuSE Linux http://www.suse.com
It sounds good!
next prev parent reply other threads:[~2001-03-07 9:21 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-03-07 5:19 Mapping a piece of one process' addrspace to another? Jeremy Elson
2001-03-07 5:55 ` Alexander Viro
2001-03-07 6:02 ` Marcelo Tosatti
2001-03-07 8:13 ` Jeremy Elson
2001-03-07 8:40 ` Alexander Viro
2001-03-07 8:54 ` Jeremy Elson
2001-03-07 9:09 ` Alexander Viro
2001-03-07 23:22 ` James H. Cloos Jr.
2001-03-07 9:04 ` Abramo Bagnara
2001-03-07 9:10 ` Alexander Viro
2001-03-07 9:20 ` Abramo Bagnara [this message]
2001-03-07 9:49 ` Alexander Viro
2001-03-07 13:01 ` Abramo Bagnara
2001-03-07 21:02 ` Jeremy Elson
2001-03-07 8:58 ` Abramo Bagnara
2001-03-07 18:17 ` Pavel Machek
2001-03-07 10:51 Manfred Spraul
2001-03-07 13:57 Jesse Pollard
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