Re: [PATCH] Simplify memory controller and resource counter I/O

[Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>]

Paul Menage wrote:
> On 10/4/07, Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> wrote:
>> Forbidding writing to the root resource counter is a policy decision
>> I am unable to make up my mind about. It sounds right, but unless
>> we have a notion of unlimited resources, I am a bit concerned about
>> taking away this flexibility.
> 
> One big reason for doing this is to make virtualization easier - if
> you expect not to be able to write to your root cgroup's limits files,
> then it's easier to make them non-writeable for a virtual server.
> 

Can't we handle that through file system permissions? virtual servers
will not run as root

>>>> One arguable drawback to this patch is that the use of memparse() is
>>>> lost in the cleanup. Having said that, given the existing of shell
>>>> arithmetic, it's not clear to me that typing
>>>>
>> memparse(), makes it so much easier, we need to use it.
>>
>>>> echo $[2<<30] > memory.limit
>>>>
>> Very geeky! I don't like it personally
> 
> Why do you dislike it? Do you really believe that anyone using this
> interface by hand isn't going to know that MB is 2^20 and GB is 2^30?
> 

But system administrators deal with memory in MB and GB. When you go
to buy memory, you don't specify, I need 1 << 30 or 2^30 bytes of
memory :-). Most administrators track their memory using these
quantifiers.

>> Do read_uint() and write_uint(), just read and write unsigned
>> integers?
> 
> Correct.
> 

Oops.. that would be problem, what if I wanted to set my limit to
unsigned long long max?

> Paul


-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL