On 05/22/2012 06:09 PM, Arnout Vandecappelle wrote:
Hoi,
After a few minutes of running my application, I see this:
# cat /proc/xenomai/stat
CPU PID MSW CSW PF STAT %CPU NAME
1 828 22 65 0 00300182 9.8 bench_RTnet_scope_thread_loop
1 839 2 46627538 0 00300186 53.8 bench_RTnet
...
i.e. the bench_RTnet_scope_thread_loop takes 10% CPU but no
context switches. How is this possible? I've looked at the
source code and can't find an explanation: when the exectime
accounting is updated, the csw is incremented as well (in
__xnpod_schedule()).
Unless your thread which seems to repeatedly attempt to pend on some
sync object has its wait condition satisfied on entry to the syscall
most of the time, which may cause __xnpod_schedule() to leave it running
without incrementing the switch count.
I'm asking because I can't find a reason why this thread should
occupy 10% of the CPU, so I'm wondering if there's something wrong
with the accounting instead.
BTW this is on Xenomai 2.5.6, on an SMP x86 with affinity=0x01.
Regards,
Arnout
--
Philippe.
_______________________________________________
Xenomai mailing list
[email protected]
http://www.xenomai.org/mailman/listinfo/xenomai
