[rtl] RTL/Linux shared memory

[David Olofson <david.olofson@reologica.se>]

Hi again RTLers!

A while ago Ian Ridley <iridley@ingenico.com.au> posted a kernel patch
for RTL/Linux shared memory. I find an approach of this kind to "nice"
shared memory handling important for three reasons;

    1) More than 4 MB of RT shared memory must be supported
       (I need this for my project Audiality, mentioned in
       the "RTL on ARM" thread. The real time audio engine
       needs to cache lots of buffers for real time processing
       and sample playback. These buffers should be reachable
       from the non-real-time (Linux app. space) engine as
       well...)

    2) Shared memory (and RTL in general) should be as much
       plug'n'play as possible, so that one doesn't need to
       tweak kernel options and config files for every system
       an RTL program is installed on. (The instrument firmware
       I'm developing for my company will be installed as an
       upgrade for different instruments, with different memory
       sizes and CPU's, and installations should be possible to
       do on location by non-Linux-users. "No configuration
       tweaking, please!")

    3) RT shared memory should be a flexible system resource that
       allows several applications to take advantage of it
       simultaneously in the usual UNIX spirit. This is not
       possible if absolute memory addresses are used!

So, what's going on with RT shared memory? Has any further work been
done?

I will need this functionality for Audiality when it's about to be
released to "average" music software users. It would be nice if
Audiality could be installed by other than (RT-)Linux gurus...

By the way, are there currently any serious plans to include RTL in the
Linux kernel distribution? (I think someone posted a message about this
long ago.)

RT is useful not only for "classic" real time applications, but should,
IMHO also be the base of multimedia systems, the high end ones in
particular. (Or do people enjoy jerks, flicker and drop-outs???)

David


--- [rtl] ---
For more information on Real-Time Linux see:
http://www.rtlinux.org/