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Clock/interrupt latency
- From: "Daniel Lidsten" <Daniel dot Lidsten at combitechsystems dot com>
- To: "eCos Discussion" <ecos-discuss at sources dot redhat dot com>
- Date: Thu, 28 Aug 2003 11:32:11 +0200
- Subject: [ECOS] Clock/interrupt latency
Hi,
I have a question regarding the clock/interrupt latency (on a MPC823e).
When i run the tm_basic test then i get a very high variation in the
measured times as you can see below.
If i look in the realtime characterization section in the user manual
then i find a variation of 3 to 5 times between maximun and average to
be normal, not as much as my measure.
---- tm_basic diag------
4.75 3.84 158.72 0.00 Clock/interrupt latency
5.32 3.84 12.16 0.00 Clock DSR latency
---- tm_basic ------
I tried to define diag_printf as printf and then i got the below
measurements. How come that diag_printf has that effect on my measure?
---- tm_basic printf ------
4.75 3.84 8.96 0.00 Clock/interrupt latency
5.20 3.52 11.84 0.00 Clock DSR latency
---- tm_basic ------
Regards, Daniel
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