Just one more question about the latency test:
Is the "Timer Handler" test an ISR so that the latency of this test tells us
the interrupt latency or do I have to run an other test to determine the
interrupt latency?.
If Timer Handler is an ISR could you tell me why "ordinary" Linux load has
influence on this latency?
I tried to run the latency test also on a kernel 2.4.25 with Xenomai 2.5.6 but
I get the error message " Xenomai: mmap local sem heap: No such device or
address" (see below). Do you have an idea what is wrong? Google says something
about a missing /dev/rtheap, but this device is available on my system.
Many thanks in advance
Roderik
---------------------------------------------------------------------------------------
mrconfig:/fat/sbin # latency -t0
Xenomai: mmap local sem heap: No such device or address
mrconfig:/fat/sbin # strace latency -t0
execve("/fat/sbin/latency", ["latency", "-t0"], [/* 37 vars */]) = 0
:
:
access("/dev/rtheap", F_OK) = 0
rt_sigaction(SIGILL, {0xff23cb8, [ILL], SA_RESTART}, {SIG_DFL}, 8) = 0
rt_sigaction(SIGILL, {SIG_DFL}, {0xff23cb8, [ILL], SA_RESTART}, 8) = 0
open("/dev/rtheap", O_RDWR) = 3
ioctl(3, 0, 0xcfbf4210) = 0
mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = -1 ENXIO (No such
device or address)
close(3) = 0
dup(2) = 3
fcntl64(3, F_GETFL) = 0x2 (flags O_RDWR)
fstat64(3, {st_mode=S_IFCHR|0600, st_rdev=makedev(4, 64), ...}) = 0
ioctl(3, TCGETS, {B38400 opost isig icanon echo ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x30016000
_llseek(3, 0, 0x7fffeac8, SEEK_CUR) = -1 ESPIPE (Illegal seek)
write(3, "Xenomai: mmap local sem heap: No"..., 56Xenomai: mmap local sem heap:
No such device or address
) = 56
close(3) = 0
munmap(0x30016000, 4096) = 0
exit(1) = ?
mrconfig:/fat/sbin # ll /dev/rtheap
crw-rw-rw- 1 root root 10, 254 May 19 14:16 /dev/rtheap
mrconfig:/fat/sbin #
mrconfig:/fat/sbin # uname -r
2.4.25
mrconfig:/fat/sbin # cat /proc/xenomai/version
2.5.6
---------------------------------------------------------------------------------------
> -----Ursprüngliche Nachricht-----
> Von: Philippe Gerum [mailto:[email protected]]
> Gesendet: Mittwoch, 1. Juni 2011 14:09
> An: Wildenburg, Roderik RAEK1 MRA
> Cc: [email protected]
> Betreff: Re: [Xenomai-help] Xenomai latency measurements
>
> On Wed, 2011-06-01 at 13:14 +0200, [email protected]
> wrote:
> > I performed some measurements with the Xenomai latency test.
> > In case somebody is interested I attached the results for our PPC-System
> > (5200B 400MHZ).
> > In this document I also compared latencies of kernel 2.4 with kernel
> > 2.6.
> > Any comments are welcome, especially whether the values I measured are
> > reasonable for a 400MHZ PPC.
> >
>
> Yes, they look like ok but the CPU frequency is not what makes the
> difference, the performance of the memory subsystem does - particularly
> since ppc MMU management is software-assisted.
>
> We would have more significant information by comparing Xenomai 2.5.6
> over Linux 2.4.25.
>
> > Roderik
> >
> > --------------------------------------------------------
> > manroland AG
> > Vorsitzender des Aufsichtsrates: Hanno C. Fiedler
> > Vorstand: Gerd Finkbeiner (Vorsitzender), Dr. Ingo Koch, Dr. Markus Rall,
> > Paul
> Steidle
> > Sitz der Gesellschaft: Offenbach am Main, Registergericht: Amtsgericht
> Offenbach HRB-Nr. 42592
> > USt-Ident-Nr. DE 250200933
> > _______________________________________________
> > Xenomai-help mailing list
> > [email protected]
> > https://mail.gna.org/listinfo/xenomai-help
>
> --
> Philippe.
>
>
--------------------------------------------------------
manroland AG
Vorsitzender des Aufsichtsrates: Hanno C. Fiedler
Vorstand: Gerd Finkbeiner (Vorsitzender), Dr. Ingo Koch, Dr. Markus Rall, Paul
Steidle
Sitz der Gesellschaft: Offenbach am Main, Registergericht: Amtsgericht
Offenbach HRB-Nr. 42592
USt-Ident-Nr. DE 250200933
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