From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gilles Chanteperdrix MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17467.39989.698322.9385@domain.hid> Date: Tue, 11 Apr 2006 14:08:21 +0200 Subject: Re: [Xenomai-help] Non-deterministic behaviour in primary mode In-Reply-To: <1144724767.27088.258799393@domain.hid> References: <1143612388.32703.257789950@domain.hid> <442A7D19.2000009@domain.hid> <1143694058.30209.257882137@domain.hid> <442C46EC.6000605@domain.hid> <1143790982.14016.257982746@domain.hid> <442CFCA3.4070704@domain.hid> <17453.19513.723459.198259@domain.hid> <1144724767.27088.258799393@domain.hid> List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Saul Cc: xenomai@xenomai.org 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.