From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To: Terry Fryar <terry.fryar@domain.hid>
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] Xenomai IRQ question
Date: Tue, 17 Jan 2012 20:27:52 +0100 [thread overview]
Message-ID: <4F15CBB8.1070406@domain.hid> (raw)
In-Reply-To: <2F9F10CEA75644AA8CF542029C058C57@domain.hid>
On 01/17/2012 05:25 PM, Terry Fryar wrote:
> Ok, on a falling edge irq, I'm using an RTDM driver and I'm down to 2.3uS,
> which is quite an improvement. However, it's still not fast enough...I need
> to hit a window of about 500nS. Any other suggestions?
>From what I recall, irq latency under load on a 720 MHz OMAP3 is more
around 20us.
>
> I use the rtdm_irq_request to hook the ISR, and I set up the irq by hand
> using mem mapping to directly access the registers on the beagle. At this
> point, I'm not sure where else to try and speed things up?
500ns is not much. I do not think we support this kind of latency on any
processor.
--
Gilles.
next prev parent reply other threads:[~2012-01-17 19:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 23:36 [Xenomai-help] Xenomai IRQ question Terry Fryar
2012-01-17 0:23 ` Gilles Chanteperdrix
2012-01-17 16:25 ` Terry Fryar
2012-01-17 19:27 ` Gilles Chanteperdrix [this message]
2012-01-17 21:01 ` Terry Fryar
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