On 10/29/07, garryt <[EMAIL PROTECTED]> wrote:
> Hello all,
>
> I had time to try again adeos+xenomai on a imx1 board. (i know this is quite
> old).
Thanks. The imx port should be integrated in the next I-pipe patch.
>
> This looks stable, i have been testing for several hours.
>
> I have followed the wiki documentation and performed some tests with
> xeno-test +
> ping flooding on this board, again i have no other *similar* board to compare
> results with, but here they are.
>
> I wonder if the difference between user-mode and in-kernel mode should be as
> much as this...
>From the tests I have seen so far, except those published by Adeneo,
there is always a great difference between user-mode an kernel-mode.
This is the price to pay for the comfort of user-space on ARM.
>
> By the way enabling ipipe tracer increase response time by a factor 2! is this
> ok with such HW ?
I guess so.
>
> I have attached the patch if someone is interested in, any remarks regarding
> this are welcome.
There is something suspicious, it is the loop:
do {
write_seqlock(&xtime_lock);
timer_tick();
+#ifdef CONFIG_IPIPE
+ last_jiffy_time += LATCH;
+#endif /* CONFIG_IPIPE */
write_sequnlock(&xtime_lock);
IMX_TCMP(TIMER_BASE) += evt_diff;
} while (unlikely((int32_t) (IMX_TCMP(TIMER_BASE)
- IMX_TCN(TIMER_BASE)) < 0));
First, you should not touch IMX_TCMP(TIMER_BASE) in the loop, this is
done by __ipipe_mach_set_dec.
Second, with the current version of the I-pipe, the do/while loop
should be disabled when CONFIG_IPIPE is enabled. However, this is
going to change in the next version of I-pipe because of the so-called
"flat log" optimization, but I think IMX_TCMP(TIMER_BASE) should be
replaced with last_jiffy_time, because IMX_TCMP(TIMER_BASE) is the
date of the previous hardware timer tick, but the previous hardware
timer tick is not necessarily Linux timer previous tick. Anyway, I
will try and fix this and send a patch for testing.
>
>
> All tests have been performed with xeno-test + ping flooding the board.
For a load that give worse figures, run the calibrator
http://www.cwi.nl/~manegold/Calibrator
--
Gilles Chanteperdrix
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