From alsa-devel-owner@alsa.jcu.cz  Tue Jan 12 19:06:51 1999
Received: from ife.ee.ethz.ch (ife-fast.ee.ethz.ch [129.132.24.193])
	by marvin.jcu.cz (8.9.1a/8.9.1) with ESMTP id TAA09217
	for <alsa-devel@alsa.jcu.cz>; Tue, 12 Jan 1999 19:05:29 +0100
Received: from ife.ee.ethz.ch (eldrich.ee.ethz.ch [129.132.24.203])
	by ife.ee.ethz.ch (8.8.5/8.8.5) with ESMTP id TAA22444
	for <alsa-devel@alsa.jcu.cz>; Tue, 12 Jan 1999 19:05:28 +0100 (MET)
Message-ID: <369B8EE7.2AC40BE9@ife.ee.ethz.ch>
Date: Tue, 12 Jan 1999 19:05:27 +0100
From: Thomas Sailer <sailer@ife.ee.ethz.ch>
MIME-Version: 1.0
To: alsa-devel@alsa.jcu.cz
Subject: Re: Linux scheduler issues.
References: <19990112144344Z2989-2279+2024@nic.funet.fi>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Reply-To: alsa-devel@alsa.jcu.cz
Sender: alsa-devel-owner@alsa.jcu.cz
Precedence: list

Juhana Sadeharju wrote:

> the other process. The strange is that the second process did read the
> initial value from the shared memory even the first process constantly
> changed it. I even tried with "volatile" after my friend suggested it

Did you map your "shared memory" region MAP_PRIVATE by chance?
Your only chance to get a shared memory region for this purpose
is SysV SHM currently, man shmget.

> and the two processes switched quite lazily. With such lazy switching
> there is no way to do a realtime processing. Would the situation be

Have you done sched_setscheduler(SCHED_FIFO,...)?

Tom

