From: Robert Schwebel <r.schwebel@pengutronix.de>
To: "M. Koehrer" <mathias_koehrer@arcor.de>
Cc: linux-rt-users@vger.kernel.org
Subject: Re: Triggering UserCode from KernelModule (IRQ)
Date: Wed, 22 Apr 2009 21:59:56 +0200 [thread overview]
Message-ID: <20090422195956.GM5367@pengutronix.de> (raw)
In-Reply-To: <6669682.1240409688443.JavaMail.ngmail@webmail19.ha2.local>
On Wed, Apr 22, 2009 at 04:14:48PM +0200, M. Koehrer wrote:
> However, there is one operation mode that uses interrupts to signal
> incoming data. The interrupt handler is realized as a tiny kernel
> module (that one that provides also the mmap for the user mode
> application). Now I am not sure how the signalling of the IRQ from
> kernel to user mode could be realized best (in terms of low latency).
>
> The "classical" approach for this task is to provide a character
> driver with a .poll file operation. In Xenomai I could use a semaphore
> that was accessible from kernel and user space for this. What is the
> best way in the RT_PREEMPT "world"?
UIO might be a good choice here, the rest is giving the interrupt
handler and the processes the right priorities.
rsc
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
next prev parent reply other threads:[~2009-04-22 19:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200904221628.27659.claus.gindhart@kontron.com>
2009-04-22 14:14 ` Triggering UserCode from KernelModule (IRQ) M. Koehrer
2009-04-22 14:36 ` Daniel Walker
2009-04-22 19:59 ` Robert Schwebel [this message]
2009-04-23 6:36 ` M. Koehrer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090422195956.GM5367@pengutronix.de \
--to=r.schwebel@pengutronix.de \
--cc=linux-rt-users@vger.kernel.org \
--cc=mathias_koehrer@arcor.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).