Messages in this thread | | | Subject | Re: cgroup, RT reservation per core(s)? | From | Peter Zijlstra <> | Date | Tue, 10 Feb 2009 14:06:17 +0100 |
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On Mon, 2009-02-09 at 20:04 +0000, Rolando Martins wrote:
> I should have elaborated this more: > > root > ----|---- > | | > (0.5 mem) 0 1 (100% rt, 0.5 mem) > --------- > | | | > 2 3 4 (33% rt for each group, 33% mem > per group(0.165)) > Rol
Right, i think this can be done.
You would indeed need cpusets and sched-cgroups.
Split the machine in 2 using cpusets.
___R___ / \ A B
Where R is the root cpuset, and A and B are the siblings. Assign A one half the cpus, and B the other half. Disable load-balancing on R.
Then using sched cgroups create the hierarchy
____1____ / | \ 2 3 4
Where 1 can be the root group if you like.
Assign 1 a utilization limit of 100%, and 2,3 and 4 a utilization limit of 33% each.
Then place the tasks that get 100% cputime on your 2 cpus in cpuset A and sched group 1.
Place your other tasks in B,{2-4} respectively.
The reason this works is that bandwidth distribution is sched domain wide, and by disabling load-balancing on R, you split the schedule domain.
I've never actually tried anything like this, let me know if it works ;-)
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