[Devel] Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added user memory)

[Balbir Singh]

Dave Hansen wrote:
> On Fri, 2006-09-08 at 11:33 +0400, Pavel Emelianov wrote:
>> I'm afraid we have different understandings of what a "guarantee" is.
> 
> It appears so.
> 
>> Don't we?
>> Guarantee may be one of
>>
>>   1. container will be able to touch that number of pages
>>   2. container will be able to sys_mmap() that number of pages
>>   3. container will not be killed unless it touches that number of pages
> 
> A "death sentence" guarantee?  I like it. :)
> 
>>   4. anything else
>>
>> Let's decide what kind of a guarantee we want.

I think of guarantees w.r.t resources as the lower limit on the resource.
Guarantees and limits can be thought of as the range (guarantee, limit]
for the usage of the resource.

> 
> I think of it as: "I will be allowed to use this many total pages, and
> they are guaranteed not to fail."  (1), I think.  The sum of all of the
> system's guarantees must be less than or equal to the amount of free
> memory on the machine.  
> 

Yes, totally agree.

> If we knew to which NUMA node the memory was going to go, we might as
> well take the pages out of the allocator.
> 
> -- Dave
> 
-- 

	Balbir Singh,
	Linux Technology Center,
	IBM Software Labs