Re: [PATCH] Run PCI driver initialization on local node

[Andi Kleen]

On Wed, Jul 06, 2005 at 11:01:14AM -0700, Christoph Lameter wrote:
> On Wed, 6 Jul 2005, Andi Kleen wrote:
> 
> > On Wed, Jul 06, 2005 at 09:35:32AM -0700, Christoph Lameter wrote:
> > > On Wed, 6 Jul 2005, Andi Kleen wrote:
> > > 
> > > > Instead of adding messy kmalloc_node()s everywhere run the 
> > > > PCI driver probe on the node local to the device.
> > > > Then the normal NUMA aware allocators do the right thing.
> > > 
> > > That depends on the architecture. Some do round robin allocs for periods 
> > > of time during bootup. I think it is better to explicitly place control 
> > 
> > slab will usually do the right thing because it has a forced
> > local node policy, but __gfp might not.
> 
> GFP allocs may not do the right thing. If you want to do this then it 
> may be best to set the memory policy to restrict allocations to the node 
> on which the device resides.

They will do the right thing. Under memory pressue on the node 
it is better to back off than to fail.

> 
> Plus there are CPU less nodes. What happens to those?

They are not worse off that they are now.

> 
> > Patching every driver in existence? That sounds like a lot of
> > work. 
> 
> No just patch those that would benefit from it. The existing 

This would be "all devices that SGI ships on Altixes" ?

IMHO all can benefit.

-Andi
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