On Tue, 2011-06-21 at 12:04 +0200, roderik.wildenb...@manroland.com wrote: > I confirm that switchtest runs (nearly) perfectly on PPC-Kernel 2.6.34 with > Xenomai 2.5.6. The only anomaly I could see is a "collapse" of the number of > context switches exactly every 7 seconds by 2% (see below). Is this worth to > pay attention to? (No other Xenomai-Task is running except for a watchdog > task with a period of 500ms)
2% off seems a lot for a transient load, and this would not happen on a periodic basis anyway. This needs to be investigated. Could you run switchtest in nofpu mode? > > On the opposite, switchtest runs erratic on PPC-2.4.25 with Xenomai 2.5.6 as > you already mentioned: The number of context switches is much smaller then > (only about 2%) with PPC-2.6.34 and fluctuate very much (see below). > Do you think you will find some spare time to fix this Problem? > Spare time has become a luxury over the last months. I'll try to find a time slot next week to have a look at this again. > Roderik > > > Xenomai 2.5.6 on PPC-2.6.34: > RTH|ctx switches|-------total > RTD| 4347| 7290193 > RTD| 4347| 7294540 > RTD| 4347| 7298887 > RTD| 4347| 7303234 > RTD| 4282| 7307516 > RTD| 4345| 7311861 > RTD| 4345| 7316206 > RTD| 4347| 7320553 > RTD| 4347| 7324900 > RTD| 4347| 7329247 > RTD| 4347| 7333594 > RTD| 4282| 7337876 > RTD| 4345| 7342221 > RTD| 4345| 7346566 > RTD| 4347| 7350913 > RTD| 4347| 7355260 > RTD| 4347| 7359607 > RTD| 4347| 7363954 > RTD| 4282| 7368236 > RTD| 4345| 7372581 > RTD| 4345| 7376926 > RTT| 00:28:31 > WE01:~ # cat /proc/xenomai/sched > CPU PID CLASS PRI TIMEOUT TIMEBASE STAT NAME > 0 0 idle -1 - master R ROOT > 0 0 rt 99 496ms670us master D rt-watchdog > > > Xenomai 2.5.6 on PPC-2.4.25: > RTH|ctx switches|-------total > RTD| 138| 25321 > RTD| 73| 25394 > RTD| 65| 25459 > RTD| 138| 25597 > RTD| 73| 25670 > RTD| 65| 25735 > RTD| 138| 25873 > RTD| 138| 26011 > RTD| 138| 26149 > RTD| 138| 26287 > RTD| 138| 26425 > RTD| 138| 26563 > RTD| 138| 26701 > RTD| 138| 26839 > RTD| 138| 26977 > RTD| 73| 27050 > RTD| 65| 27115 > RTD| 138| 27253 > RTD| 138| 27391 > RTD| 138| 27529 > RTD| 138| 27667 > RTT| 00:09:48 > mrconfig:~ # cat /proc/xenomai/sched > CPU PID CLASS PRI TIMEOUT TIMEBASE STAT NAME > 0 0 idle -1 - master R ROOT > 0 0 rt 60 185ms803us master D rt-watchdog > > > > -----Ursprüngliche Nachricht----- > > Von: Philippe Gerum [mailto:r...@xenomai.org] > > Gesendet: Samstag, 18. Juni 2011 16:22 > > An: Gilles Chanteperdrix > > Cc: Wildenburg, Roderik RAEK1 MRA; xenomai-help@gna.org > > Betreff: Re: [Xenomai-help] Xenomai 2.5.6 with PPC-Kernel 2.4.25 > > > > On Sat, 2011-06-18 at 15:44 +0200, Gilles Chanteperdrix wrote: > > > On 06/18/2011 10:50 AM, Philippe Gerum wrote: > > > > On Tue, 2011-06-14 at 14:47 +0200, roderik.wildenb...@manroland.com > > > > wrote: > > > >> Perhaps this may help: > > > >> I instrumented src/common/sem_heap.c and ksrc/nucleus/heap.c with > > > >> printf > > and printk (see appended files) and this is the output: > > > >> > > > >> 1:mrconfig:~ # latency > > > >> 2:xeno_init_private_heap > > > >> 3:map_sem_heap syscall 0 > > > >> 4:xeno_map_heap open 3 > > > >> 5:xnheap_ioctl private data: 00000000 > > > >> 6:xeno_map_heap ioctl 0 handle 0xc7dd9210 > > > >> 7:xnheap_mmap 00000000 00000000 > > > >> 8:xeno_map_heap 0xffffffff > > > >> 9:Xenomai: mmap local sem heap: No such device or address > > > >> 10:mrconfig:~ # > > > >> > > > >> > > > >> It looks like (if I figured it out correctly) as if in function > > > >> sem_heap.c- > > >xeno_map_heap() (which is called from xeno_init_privat_heap() via function > > map_sem_heap()) the ioctl-Call fails. > > > >> xeno_map_heap() passes correctly an argument unequal NULL as third > > parameter to ioctl() (line6), but in kernel space function xnheap_ioctl() > > the 3. > > parameter arrives as NULL(line 5). This sets file->private_data to NULL > > which in > > turn lets xnheap_mmap() fail, as this function expects file->private_data > > != NULL > > (line7). > > > >> Therefore xnheap_mmap() returns -ENIXIO to xeno_map_heap() which > > outputs the error message " Xenomai: mmap local sem heap: No such device or > > address". > > > >> The one million dollar question is, why the 3. parameter of ioctl() > > > >> mutates to > > NULL. Any idea? > > > >> > > > >> If I can do anything else, let me know. > > > >> > > > > > > > > You will need these patches to run linux 2.4.25 over 2.5.6. The first > > > > one fixes the ioctl() issue. > > > > http://git.xenomai.org/?p=xenomai- > > rpm.git;a=commit;h=c2a24b90667e12d0614e5d8442dba74f137f9d4d > > > > http://git.xenomai.org/?p=xenomai- > > rpm.git;a=commit;h=bebc2a8e6b430c99041800330dc6061665371d90 > > > > > > > > Note: the switch test does not seem to be running correctly on my > > > > icecube (albeit the latency one does), somehow linux reschedule events > > > > get lost. For this reason, I would not consider the current state as > > > > being production-grade. > > > > > > How do you see that reschedule events are lost? > > > > The pace of the supposedly 1sec periodic display stabilizes only when > > other processes run in the background and becomes erratic when the > > switch test is running alone, whilst the system does not seem to lose > > its idea of time. Additionally, signals do not seem to make their way to > > the shadows upon ^C. I did not track the issue in depth though, so at > > this stage I'm speculating. > > > > > Does this happen also on > > > other systems? > > > > > > > Can't tell, I'm not using 2.5.x that much these days. I did not see any > > issue during the sh4 port, which seems to exclude 2.6.x from the > > potential victims. > > > > Guts feeling is that this might be specific to 2.4 kernels. > > > > -- > > 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 > -- Philippe. _______________________________________________ Xenomai-help mailing list Xenomai-help@gna.org https://mail.gna.org/listinfo/xenomai-help
