* Karim Yaghmour <[email protected]> wrote:
> > so ... give the -50-12 -RT tree a try and report back the lpptest
> > results you are getting.
>
> First things first, we want to report back that our setup is validated
> before we go onto this one. So we've modified LRTBF to do the
> busy-wait thing.
here's another bug in the way you are testing PREEMPT_RT irq latencies.
Right now you are doing this in lrtbf-0.1a/drivers/par-test.c:
if (request_irq ( PAR_TEST_IRQ,
&par_test_irq_handler,
#if CONFIG_PREEMPT_RT
SA_NODELAY,
#else //!CONFIG_PREEMPT_RT
SA_INTERRUPT,
#endif //PREEMPT_RT
you should set the SA_INTERRUPT flag in the PREEMPT_RT case too! I.e.
the relevant line above should be:
SA_NODELAY | SA_INTERRUPT,
otherwise par_test_irq_handler will run with interrupts enabled, opening
the window for other interrupts to be injected and increasing the
worst-case latency! Take a look at drivers/char/lpptest.c how to do this
properly. Also, double-check that there is no IRQ 7 thread running on
the PREEMPT_RT kernel, to make sure you are measuring irq latencies.
Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
- References:
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
- Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]