Any differents in time-behavior ?

QNX DEVELOPERS General Programming
1

Hi Community!!!

Does it gives any interesting or important differents in time-behavior between QNX Neutrino and QNX 4 ?

Thank You !!!

2

Could you be a little more specific?

3

Thank You maio

Message Passing with MsgSend() vs. Send() and why is MsgSend() slower?
Queue why is Neutrino faster?
Shared memory and why ist Neutrino slower?
Kommunication over a date file?
Ticksize

And more important, other Things I dont know!!!

Thank you!!!

4

Sorry: Communication over a data file !!!

5

Neutrino is slower over shared memory??? That I’m very surprise, this is typicaly not influence by the kernel, how did you come to this conclusion.

Yes in general Neutrino is a bit slower at everything because it’s smarter and has more features. For example it has DLL and QNX4 doesn’t dll is slower then static code, yet dll provide more flexibility and can reduce memory usage (in theory)

What do you mean by ticksize.

Neutrino and QNX4 are totaly two different OSes, you should not assume they will perform equally.

6

Thank you mario !!!

I come to this conclusion because counting bytes on both Versions on the same PC.

Ticksize in QNX4 is usually 10ms and can be changed (smallest time resolution)
in Neutino the equivalent is " ClockPeriod" ???

Do you know other things I dont know about slower or faster because
this is interresting for me.

Thank you !!!

7

For the ticksize:
I am quite sure I read something about time resolution in the example chapter of Getting Started with QNX Neutrino 2: “Clocks, Timers, and Getting a Kick Every So Often” which is available in the documentation.

Documentation also says that ClockPeriod() is the QNX Neutrino equivalent to qnx_ticksize().

RTFM :wink:

8

Here you are comparing compiler (and compiler options). I very much doubt there is a difference between the two OS in that regard.

Yes, in QNX6 you can go to lower ticksize then in QNX4.

Nothing specific I’m afraid.

You’re welcome

9

Thank you Mario!

This is very interesting, you mean the only difference is in compiler options.
Yes this is possible it is a new awareness for me.

Does it makes any difference for data rate, if I run in root or in normal mode ?

And what’s the smallest Time resolution in Neutrino?

Thank you !!!