cgroup, RT reservation per core(s)?

[Rolando Martins]

Hi,
I would like to have in a quad-core, 1 core totally (100%) dedicated
to RT tasks (SCHED_RR and SCHED_FIFO) and the other 3 cores with
normal behavior, better said,  allowing SCHED_OTHER & SCHED_FIFO &
SCHED_RR tasks but still with a RT reservation. Follows an example:


# Setup first domain (cpu 0,1,2)
echo 0-2 > /dev/cgroup/0/cpuset.cpus
echo 0 > /dev/cgroup/0/cpuset.mems

# Setup RT bandwidth for firstdomain (80% for RT, 20% others)
echo 1000000 > /dev/cgroup/0/cpu.rt_period_us
echo 800000 > /dev/cgroup/0/cpu.rt_runtime_us


# Setup second domain (cpu 3)
mkdir /dev/cgroup/1
echo 3 > /dev/cgroup/1/cpuset.cpus
echo 0 > /dev/cgroup/1/cpuset.mems

# Setup RT bandwidth for second domain (100% for RT)
echo 1000000 > /dev/cgroup/1/cpu.rt_period_us
echo 1000000 > /dev/cgroup/1/cpu.rt_runtime_us

# Setup RT bandwidth for third domain
echo 1000000 > /dev/cgroup/1/0/cpu.rt_period_us
echo 500000 > /dev/cgroup/1/0/cpu.rt_runtime_us

# Setup RT bandwidth for fourth domain
echo 1000000 > /dev/cgroup/1/1/cpu.rt_period_us
echo 500000 > /dev/cgroup/1/1/cpu.rt_runtime_us


                                            root
                                         ----|----
                                         |          |
(80% rt, 20% others         0         1 (100% rt @ core 3)
@ cores 1,2,3)                          ------
                                                  |    |
                                                  0   1   (50% rt for
each group @ core 3)




Is there anyway for doing this?
Or must we have a separate /proc/sys/kernel/sched_rt_runtime_us &
/proc/sys/kernel/sched_rt_period_us for each core/cpu?
In this case:
/proc/sys/kernel/sched_rt_runtime_us_0
/proc/sys/kernel/sched_rt_period_us_0
...
/proc/sys/kernel/sched_rt_runtime_us_n (n, cpu count)
/proc/sys/kernel/sched_rt_period_us_n

Thanks,
Rol