Re: [PATCH 1/5] cpuset memory spread basic implementation

[Ingo Molnar <mingo@elte.hu>]

* Christoph Lameter <clameter@engr.sgi.com> wrote:

> > but a single object cannot be allocated both locally and globally!  
> > (well, it could be, for read-mostly workloads, but lets ignore that 
> > possibility) So instead of letting chance determine it, it is the most 
> > natural thing to let the object (or its container) determine which 
> > strategy to use - not the workload. This avoids the ambiguity at its 
> > core.
> 
> We want cpusets to make a round robin allocation within the memory 
> assigned to the cpuset. There is no global allocation that I am aware 
> of.

i think we might be talking about separate things, so lets go one step
back.

firstly, i think what you call roundrobin is what i call 'global'.  
[roundrobin allocation is what is best for a cache that is accessed in a 
'global' way - as opposed to cached data that is accessed in a 'local' 
way.]

secondly, i'm not sure i understood it correctly why you want to have 
all (mostly filesystem related) allocations within selected cpusets go 
in a roundrobin way. My understanding so far was that you wanted this 
because the workload attached to that cpuset was using the filesystem 
objects in a 'global' way: i.e. from many different nodes, with no 
particular locality of reference. Am i mistaken about this?

	Ingo