Messages in this thread | | | From | David Brownell <> | Subject | Re: High resolution timers on AT91SAM926x | Date | Mon, 3 Mar 2008 17:29:18 -0800 |
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On Monday 03 March 2008, Bosko Radivojevic wrote: > I had CONFIG_ATMEL_TCLIB enabled, but not TCB_CLKSRC and > TCB_CLKSRC_BLOCK=0. With all those options, I finally have HRT > functionality. But, strange thing is that jitter of my little example > (get time, sleep 1ms, get time, show the difference) is around 250us. > Maybe this is normal for this architecture?
I have no idea why that would be. Maybe you can find out. :)
> System is (as noted on rt.wik site) very slow with NO_HZ option enabled.
It doesn't exactly say *why* or compare to other arm926ejs chips ...
Could the 64-bit math (ktime stuff) be a factor there? Your board probably only runs at 95 (or-so) bogomips after all.
And is that just a NO_HZ issue, or generically an issue when oneshot timer modes are in heavy use?
- Dave
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