Re: [ECOS] Tuning the clock Tick Time

[R Vamshi Krishna <vamshi at cse dot iitb dot ac dot in>]

I think it was my mistake because I did not properly phrase my question.
In RTLinux not only latencies but also periodicity of threads can also be 
given in terms of Micro-Seconds.

So in eCos when I correspondigly write alarms, I want to be able to set 
alarms of micro-seconds range.

Is it possible ??

If Context switches are indeed in micro-seconds range, and default 
tick-time is 100 per second, then how can I find out the exact time for 
context switch in eCos ?

On Mon, 19 Dec 2005, Gary Thomas wrote:

> On Tue, 2005-12-20 at 01:12 +0530, R Vamshi Krishna wrote:
> > Hello,
> >
> > I am using a Pentium IV as my target system and since the system is fast
> > enough, I want to see to how small can I make the "tick" time be and still
> > manage my applications.
> >
> > To that end can anyone tell how can I decrease the tick time (say in
> > micro-seconds range).
> >
> > Actually we have an application that runs on RTLinux. I want to see if we
> > can do that in eCos. RTlinux provides very small latencies (micro-seconds
> > range). Hence I want to check if eCos can also do that.
>
> eCos can definitely provide micro-second event latencies.  This is not
> related to how fast the clock runs though - a well designed system does
> not rely on a clock/timer to make things happen.
>
> > RTLinux also has a small test that prints all the latencies. Is something
> > like that available for eCos.
>
> Look at CYGVAR_KERNEL_COUNTERS_CLOCK_LATENCY and CYGVAR_KERNEL_COUNTERS_CLOCK_DSR_LATENCY
> in the kernel package.  These can be enabled and the 'tm_basic' program
> will use them, providing a simple measure of clock/timer ISR and DSR
> latencies.

--
Regards,
Vamshi

-------------------------------------------------
R.Vamshi Krishna,
M.Tech. CSE (II year),
IIT Bombay
Room no. 320, A-wing, Hostel-12
Mobile : +919869781633
-------------------------------------------------

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