Re: [Xenomai-help] CONFIG_PREEMPT & irqbench

From: Markus Franke <Markus.Franke@domain.hid>
To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: Xenomai-help@domain.hid
Subject: Re: [Xenomai-help] CONFIG_PREEMPT & irqbench
Date: Wed, 14 Feb 2007 10:59:08 +0100	[thread overview]
Message-ID: <45D2DD6C.9010005@domain.hid> (raw)
In-Reply-To: <45D2CF9E.40308@domain.hid>

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> Hmm, I should have better said "tiny". This experience is based on
> I-pipe tracer observations, and I guess you don't have that thing on,
> have you?

I have set:

---snip---
# CONFIG_IPIPE_DEBUG is not set
CONFIG_IPIPE_TRACE_ENABLE_VALUE=0
---snap---

in both kernels (either with preempt or without).

> How much is the difference? How long did you measure to exclude noise.

The difference is about 1 us (in average and worst case) when running
irqloop in IRQ handler mode.

I have been running the measurements for 1 minute under heavy load with
an interrupt frequency of 1 ms. This gives 60000 samples. Is this too
less in order to exclude noise?

Regards,
Markus Franke

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