Re: question on sched-rt group allocation cap: sched_rt_runtime_us

[Anirban Sinha]

On 2009-09-08, at 1:42 AM, Peter Zijlstra wrote:

> On Tue, 2009-09-08 at 00:08 -0700, Anirban Sinha wrote:
>
> > > Actually there is, use cpusets to carve the system into partitions.
> >
> > hmm. ok. I looked at the code a little bit. It seems to me that the
> > 'borrowing' of RT runtimes occurs only from rt runqueues belonging to
> > the same root domain. And partition_sched_domains() is the only
> > external interface that can be used to create root domain out of a  
> > CPU
> > set. But then I think it needs to have CGROUPS/USER groups enabled?
> > Right?
>
> No you need cpusets, you create a partition by disabling load- 
> balancing
> on the top set, thereby only allowing load-balancing withing the
> children.

Ah I see. Thanks for the clarification.


> The runtime sharing is a form of load-balancing.

sure.


> CONFIG_CPUSETS=y


Hmm. Ok. I guess what I meant but did not articulate properly (because  
I was thinking in terms of code) was CPUSETS needed CGROUPS support:

config CPUSETS
	bool "Cpuset support"
	depends on CGROUPS


Anyway, that's fine. I'll dig around the code a little bit more.


> Documentation/cgroups/cpusets.txt

Thanks for the pointer. My bad, I did not care to see the docs. I tend  
to ignore docs and read code instead. :D


>

--
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/