Gilles Chanteperdrix 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 ?
Oh, well xawtv starts up in a window and does not change the screen resolution. The large latencies occur during program startup. I have seen no other program produce poor latencies in the latency test program. Saul. _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
