Jan Kiszka wrote:
Lauener Nathan wrote:
Hi,
I am using Xenomai to read data from different sensors in real time from
user space. So far I am reading position data from a device attached to
a serial port. The CPU load is at about 1%. I also have a
microcontroller attached via USB to read encoder data. The USB device is
a USB-to-serial converter. As soon as I open the (USB-)serial port with
normal systemcalls and read the incoming data my CPU load skyrockets to
over 90%. I only read about 30 bytes every 100ms.
I ran the application on a much newer computer also to rule out any
buggy hardware. The results stayed the same. Intensively searching the
mailing list and provided documentation have not helped solve the
problem.
I'm using Xenomai 2.1.0 with kernel 2.6.15.6. Xenomai is compiled into
the kernel. I also use the driver xeno_16550A loaded as module. The
USB-to-serial bridge used is a CP2101 from Silabs.
Is there any IRQ conflict between the USB host controller and some
RT-device? Please check /proc/interrupts and /proc/xenomai/irq.
There is no conflict (interrupt 0 (timer) is the only interrupt
mentioned in both listings).
Which process is consuming your CPU time? At system or at user level?
It seems that the system consumes the CPU time. Here are the first few
lines from opreport
CPU: CPU with timer interrupt, speed 0 MHz (estimated)
Profiling through timer interrupt
samples % image name app name
symbol name
1733 31.9742 vmlinux vmlinux
default_idle
1151 21.2362 vmlinux vmlinux
__ipipe_trace
601 11.0886 libqt-mt.so.3.3.3 libqt-mt.so.3.3.3 (no
symbols)
528 9.7417 libc-2.3.2.so libc-2.3.2.so (no
symbols)
305 5.6273 vmlinux vmlinux
__ipipe_unstall_root
184 3.3948 vmlinux vmlinux
__ipipe_dispatch_event
122 2.2509 anon (tgid:4322 range:0x81fb000-0x89b2000)
Xorg (no symbols)
100 1.8450 libstdc++.so.5.0.7 libstdc++.so.5.0.7 (no
symbols)
97 1.7897 vmlinux vmlinux mcount
It looks like the systems gets stuck on the idle task. I do not know
what __ipipe_trace exactly does.
Jan
In my current design I acquire and process the data in the same programm
using the Xenomai native skin from user space. This means I link the
Xenomai-native and rtdm libraries with several graphics and mathematical
libraries. Could this lead to conflicts or problems with Xenomai?
Nathan
_______________________________________________
Xenomai-help mailing list
[email protected]
https://mail.gna.org/listinfo/xenomai-help
