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Subject: Re: 3.14.8@Linux: OSS priorities problem?
From: Eric Norum <[email protected]>
To: Ralph Lange <[email protected]>
Cc: EPICS Core Talk <[email protected]>
Date: Tue, 8 Nov 2005 06:55:35 -0600
On Nov 8, 2005, at 6:22 AM, Ralph Lange wrote:

On my linux box (Debian 3.1), epicsMessageQueueTestHost yields unexpected results:

aragon: .../base/3-14-X > bin/linux-x86/epicsMessageQueueTestHost
Simple single-thread tests.
[...]
Single receiver, single sender tests.
Systems with priority-based scheduler should send only
4 or 5 messages (sender priority > receiver priority).
Sent 5 messages.
Systems with priority-based scheduler should send 10
messages (sender priority < receiver priority).
Sent 5 messages.
All systems should send 10 messages (sender pauses
after sending each message).
Sent 10 messages.


Shouldn't the middle case (sender priority < receiver priority) show 10 messages being sent instead of 5?

You're seeing the fact that your linux box doesn't have a strict priority-based scheduler -- i.e. it's not a "real-time" operating system.

-- 

Eric Norum <[email protected]>

Advanced Photon Source                     

Argonne National Laboratory

(630) 252-4793





Replies:
Re: 3.14.8@Linux: OSS priorities problem? Marty Kraimer
References:
3.14.8@Linux: OSS priorities problem? Ralph Lange

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