Re: dm-ioband + bio-cgroup benchmarks

[Balbir Singh <balbir@linux.vnet.ibm.com>]

Hirokazu Takahashi wrote:
> Hi,
> 
>>> It's possible the algorithm of dm-ioband can be placed in the block layer
>>> if it is really a big problem.
>>> But I doubt it can control every control block I/O as we wish since
>>> the interface the cgroup supports is quite poor.
>> Had a question regarding cgroup interface. I am assuming that in a system,
>> one will be using other controllers as well apart from IO-controller.
>> Other controllers will be using cgroup as a grouping mechanism.
>> Now coming up with additional grouping mechanism for only io-controller seems
>> little odd to me. It will make the job of higher level management software
>> harder.
>>
>> Looking at the dm-ioband grouping examples given in patches, I think cases
>> of grouping based  in pid, pgrp, uid and kvm can be handled by creating right
>> cgroup and making sure applications are launched/moved into right cgroup by
>> user space tools. 
> 
> Grouping in pid, pgrp and uid is not the point, which I've been thinking
> can be replaced with cgroup once the implementation of bio-cgroup is done.
> 
> I think problems of cgroup are that they can't support lots of storages
> and hotplug devices, it just handle them as if they were just one resource.

Could you elaborate on this please?

> I don't insist the interface of dm-ioband is the best. I just hope the
> cgroup infrastructure support this kind of resources.
> 

What sort of support will help you?



-- 
	Balbir