Re: [patch 0/7] [RFC] SLUB: Improve allocpercpu to reduce per cpu access overhead

Christoph Lameter
2007-11-01T13:03:58Z

On Thu, 1 Nov 2007, David Miller wrote:

> > This hunk helped the sparc64 looping OOPS I was getting, but cpus hang
> > in some other fashion soon afterwards.
>
> And if I bump PER_CPU_ALLOC_SIZE up to 128K it seems to mostly work.

Good....

> You'll definitely need to make this work dynamically somehow.

Obviously. Any ideas how?

I can probably calculate the size based on the number of online nodes when
the per cpu areas are setup. But the setup is done before we even parse
command line arguments. That would still mean a fixed size after bootup.

In order to make it truly dynamic we would have to virtually map the area.
vmap? But that reduces performance.