Hi,
something take my attention ... when you say your RT task 'print a message to a log
file', are you sure you do not use kernel calls with non rt priority scheduling ??
04/01/2001 10:19:59, [EMAIL PROTECTED] wrote:
>I discovered something strange with the FIFOs (RTAI-1.5). I wrote a small RT task
>that basically put a character to a FIFO, do a few thing (print a message in the log
>file
and do a few computation). and then read the FIFO again. This is the only RT task in
>the system. So normally, you expect every read to succeed. However, I observed a
>strangebehaviour. If when my task is running, I lauch a "cat </dev/rtf10" process on
the shell prompt. The command gives me characters !!!!!!!!. So, this means that the
>rtf_put function stop the thread and do some rescheduling and so allow the linux
>process to read the character ... And the consequence is .... a simple Linux user
>space
program is able to preempt a real time task which is not the expected behaviour in a
>realtime system.
Kumsta christophe
Real-time image processing
RTAI/RTlinux (use the source luke!)
maf-roda
[EMAIL PROTECTED]
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