Re: realtime-preempt and arm

2006-12-14 Thread tike64
Steven Rostedt <[EMAIL PROTECTED]> wrote: > So you got a big jitter using nanosleep??? If that's the case, could > you post the times you got. I'll also boot a kernel with the latest > -rt patch, without highres compiled, and see if I can reproduce the > same on x86. You're very kind! Here you go

Re: realtime-preempt and arm

2006-12-14 Thread tike64
Steven Rostedt <[EMAIL PROTECTED]> wrote: > ... > it's ok for the timer to be a little over, but it must never be a > little under. > ... > So we make sure the timer goes off in (n+1) ms, and not just (n). Ok, this makes sense - thanks. What confuses / confused me is that I have 4 combinations: w

Re: realtime-preempt and arm

2006-12-14 Thread tike64
Ingo Molnar <[EMAIL PROTECTED]> wrote: > tike64 <[EMAIL PROTECTED]> wrote: > > Ok, understood; I tried this: > > > > t = raw_timer(); > > ts.tv_nsec = 500; > > ts.tv_sec = 0; > > nanosleep(&ts, 0); > > t

Re: realtime-preempt and arm

2006-12-13 Thread tike64
Steven Rostedt <[EMAIL PROTECTED]> wrote: > Also, have you tried this with a nanosleep instead of a select. > Select's timeout is just that, a timeout. It's not suppose to be > accurate, as long as it doesn't expire early. The reason I state > this, is that select uses a different mechanism than n

Re: realtime-preempt and arm

2006-12-01 Thread tike64
> Hi, > > Without the support of High Resolution Timer > supported, the timer resolution wouldn't change. Ok, I understand that. I was not expecting more resolution. I expected only that I would get more precise 10ms delays. What confuses me is that the delays roughly doubled. > With high-resolu

realtime-preempt and arm

2006-11-29 Thread tike64
Hi all, I'm trying the realtime-preempt patch-2.6.18-rt6 on lh7a400 arm system with little success. In a test program I try 5 ms timeout with select() but get 20 ms avg or 26 ms max. When the framebuffer scrolls, the max delay goes up to 59 ms. With a vanilla kernel I get 10 ms (because of tick re