From alsa-devel-owner@alsa.jcu.cz  Mon Jan 11 15:31:00 1999
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From: "Benjamin GOLINVAUX" <golinvaux@benjamin.net>
To: <alsa-devel@alsa.jcu.cz>
Subject: Scheduler issues
Date: Mon, 11 Jan 1999 15:13:14 +0100
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To be more specific about Linux: Blocking mode means that the
:thread or process is suspended until something happens (a byte or
:buffer is wriiten or read) and other threads can be run according to
:the algorithms the scheduler uses. Once the Blocking call completes,
:the thread can be run again, whenever the scheduler chooses to run it.
:But remember, besides your nice little audio app. there are quite a
:lot of system processes that can suddenly preempt at awkward moments,
:and no way of knowing what they might do to your delicate audio
:timings. Short of re-writing the Scheduler and kernel, there is not a
:lot can be done about this.
: KURT and realtime Linux are not ideal solutions either.
:Hope this helps a bit.
:
Of course, it helps.... Thanks a lot Steve. Clear summary of what happens.

However, two issues :

1) could it be possible for us tom imagine linux running (with possible
kernel modif) just ONE process. That is,
   a) is there a way to COMPLETELY STOP other processes while executing
(part of) our process,
   b) does it need a kernel patch

2) isn't it just what KURT (or RTLinux ?) promise ? From KURT manual :
"when in real-time mode, [the kernel] executes only those processes that are
marked as real-time)... Looks promising, isn't it ?

I seem to wish badly that it would be possible ;-)

BTW, your erlang language seems promising also... Does it run under Linux ?
Does it address real-time issues in Linux ?

Does it need its own OS (does not frighten me...) ? Own hardware (DOES
bother me) ?

BTW2, do you have a clue of which OS the last Fairlight series III machines
(from 1990) ran ? (might be what we are looking for)

BTW3 I eventually found people interested in the same stuff as I am (and who
are knowledgeable about it) and I'm happy, even if Linux can't do real-time
;-)



