Re: fair group scheduler not so fair?

[Chris Friesen]

Srivatsa Vaddagiri wrote:

> But first, note that Groups "a" and "b" share bandwidth with all tasks
> in /dev/cgroup/tasks.

Ah, good point.  I've switched over to your group setup for testing.

> The following experimental patch (on top of 2.6.26-rc3 +
> http://programming.kicks-ass.net/kernel-patches/sched-smp-group-fixes/) seems 
> to fix the problem.

> Can you check if this makes a difference for you as well?

Initially it looked promising.  I put pid 2498 in group A, and pids 2499 
and 2500 in group B.  2498 got basically a full cpu, and the other two 
got 50% each.

However, I then moved pid 2499 from group B to group A, and the system 
got stuck in the following behaviour:

2498 cfriesen  20   0  3800  392  336 R 99.7  0.0   3:00.22 cat
2500 cfriesen  20   0  3800  392  336 R 66.7  0.0   1:39.10 cat
2499 cfriesen  20   0  3800  392  336 R 33.0  0.0   1:24.31 cat

I reproduced this a number of times.

Chris
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/