> On 02/19/2014 03:17 AM, Yogi A. Patel wrote: >> On Feb 18, 2014, at 3:57 PM, Gilles Chanteperdrix >> <[email protected]> wrote: >> >>> On 02/18/2014 07:13 PM, Yogi A. Patel wrote: >>>> Sorry, answers below. >>>> >>>>> On Feb 18, 2014, at 10:57, Gilles Chanteperdrix >>>>> <[email protected]> wrote: >>>>> >>>>>> On 02/18/2014 04:39 PM, Yogi A. Patel wrote: Hi - >>>>>> >>>>>> I have patched Scientific Linux 6.5 (Linux kernel v >>>>>> 2.6.32.20) with >>>>> >>>>> 2.6.32 is very old. >>>>> >>>>> >>>>>> 1. I don't quite understand everything being printed out >>>>>> here, however I know that not having overruns is great - but >>>>>> I also know that the worst case latencies are not >>>>>> acceptable. >>>>> >>>>> In the example you show, the worst case latency is 11µs, is >>>>> this what you do not find acceptable? If this is indeed what >>>>> you find unacceptable, I am afraid there is little we can do. >>>> >>>> (RTXI.org) >>> >>> Website looks broken. >> >> I just checked - it is up and running. I would be interested in >> hearing your input about ours architecture and ways to make it >> better. (http://www.rtxi.org/about-rtxi/architecture/) > > Indeed, I had a "script error", which is now gone.
Glad it worked. Any comments/feedback you may have is appreciated/welcome. > >>> Probably not. It will get clock_gettime(CLOCK_HOST_REALTIME) >>> working though, that was the initial question. That said, running >>> your kernel with a different configuration could help. For instance >>> turning off CONFIG_SMP, CONFIG_FTRACE, CONFIG_PREEMPT usually helps >>> reducing latency. >> >> OK, I recompiled and reran these tests and have latencies in the >> 10-11us range, still. >> >> Question - when it says “option is not set” in the config lie, does >> that by default mean that option is set to “n”? Or should I be >> setting options to “=n” instead? > > Options have dependencies, which the configuration tool enforces, so, > editing the .config by hand is not recommended, you should use the > interactive tools instead (xconfig, or menuconfig for instance). I used menuconfig to go back and disable those three options you mentioned. Latencies are still around 11us. Also, just realized that there is an error in my title - I’m not on Ubuntu - I’m on Scientific Linux. Side question - in the processor setting section, there is an option for “Preemption Model”. I believe I should set that to "Preemptible Kernel (low latency desktop)” but am unsure. Is that correct? > -- > Gilles. _______________________________________________ Xenomai mailing list [email protected] http://www.xenomai.org/mailman/listinfo/xenomai
