From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To: Saul <xeno@domain.hid>
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai-help] Non-deterministic behaviour in primary mode
Date: Tue, 11 Apr 2006 14:08:21 +0200 [thread overview]
Message-ID: <17467.39989.698322.9385@domain.hid> (raw)
In-Reply-To: <1144724767.27088.258799393@domain.hid>
Saul wrote:
> > > > I thought SMI was supposed to increase latencies, but I only see
> > > > latencies < 60us at any load, unless I start video capture. Does
> > > > the latency test absolutely rule out SMI as the cause?
> > >
> > > Not really, e.g. if the video capture device is USB-attached, then
> > > SMI could possibly remain in the picture.
> >
> > I have used the bttv driver with xawtv or mythtv and nvidia
> > proprietary drivers on a dual pIII machine running latency and the
> > maximum latency was far less than 100 us. What produces large spots,
> > however, is switching virtual terminals or changing resolution.
> > Doesn't xawtv change resolution for full screen mode ? Did not you use
> > the 768x576 modeline hack ?
>
>
> The video capture is not USB, it's a PCI card. Since I don't see poor
> latencies I'm guessing my problem is *not* SMI related.
The latencies above 100us that you observe when starting video capture
are abnormal. I was suggesting that these latencies are not due to video
capture but to the fact that xawtv change resolution. Big latencies
when switching virtual terminal are a well-known issue, not related to
SMI. So my question was: is xawtv configured on your machine to change
resolution when starting capture ?
--
Gilles Chanteperdrix.
next prev parent reply other threads:[~2006-04-11 12:08 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-29 6:06 [Xenomai-help] Non-deterministic behaviour in primary mode Saul
2006-03-29 11:28 ` Jan Kiszka
2006-03-30 4:27 ` Saul
2006-03-29 12:27 ` Philippe Gerum
2006-03-30 4:47 ` Saul
2006-03-30 12:05 ` Gilles Chanteperdrix
2006-03-31 6:44 ` Saul
2006-03-30 21:00 ` Philippe Gerum
2006-03-31 7:43 ` Saul
2006-03-31 9:55 ` Philippe Gerum
2006-03-31 15:35 ` Gilles Chanteperdrix
2006-04-11 3:06 ` Saul
2006-04-11 12:08 ` Gilles Chanteperdrix [this message]
2006-04-12 0:56 ` Saul
2006-04-12 7:49 ` Jan Kiszka
2006-03-29 12:41 ` Philippe Gerum
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