19 Oct
2012
19 Oct
'12
6:02 p.m.
2012-10-19 15:02, Fons Adriaensen skrev:
Hello all,
My ex-collegues at Alcatel are screaming for help. They want to run
an app (as root, debatable but that's another story) using SCHED_FIFO
threads on an openSuSE 11.4 system.
Using the 'default' kernel (which has CONFIG_PREEMPT not set), this
works. Using the 'desktop' kernel (CONFIG_PREEMPT=y) they get an
EPERM when trying to start a RT thread, even as root.
As I haven't used SuSE for ages, has anyone an idea of what is
happening here ?
Try with chrt.
On my laptop with opensuse 11.4 with desktop-kernel. I started "top" as
root.
linux-do4z:~ # ps -up `pidof top`
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 15666 0.4 0.0 8848 1300 pts/19 S+ 17:54 0:00 top
linux-do4z:~ # chrt -p `pidof top`
pid 15666's current scheduling policy: SCHED_OTHER
pid 15666's current scheduling priority: 0
linux-do4z:~ # chrt -f -p 20 `pidof top`
linux-do4z:~ # chrt -p `pidof top`
pid 15666's current scheduling policy: SCHED_FIFO
pid 15666's current scheduling priority: 20
check with "chrt -m" for priorities.
regards,
/bengan