Re: [PATCH 0/3] NUMA boot hash allocation interleaving

["Martin J. Bligh" <Martin.Bligh@us.ibm.com>]

>> > I originally was a bit worried about the TLB usage, but it doesn't
>> > seem to be a too big issue (hopefully the benchmarks weren't too
>> > micro though)
>> 
>> Well, as long as we stripe on large page boundaries, it should be fine,
>> I'd think. On PPC64, it'll screw the SLB, but ... tough ;-) We can either
>> turn it off, or only do it on things larger than the segment size, and
>> just round-robin the rest, or allocate from node with most free.
> 
> Is there a reasonably easy-to-use existing infrastructure to do this?
> I didn't find anything in my examination of vmalloc itself, so I gave
> up on the idea.

Not that I know of. But (without looking at it), it wouldn't seem 
desperately hard to implement (some argument or flag to vmalloc, or vmalloc_largepage) or something.

> And just to clarify, are you saying you want to see this before inclusion
> in mainline kernels, or that it would be nice to have but not necessary?

I'd say it's a nice to have, rather than necessary, as long as it's not
forced upon people. Maybe a config option that's on by default on ia64
or something. Causing yourself TLB problems is much more acceptable than
causing it for others ;-)

M.

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