Re: [patch 01/41] cpu_alloc: Increase percpu area size to 128k

Rusty Russell
2008-06-02T23:51:36Z

On Tuesday 03 June 2008 03:58:17 Luck, Tony wrote:
> > The per cpu allocator requires more per cpu space and we are already near
> > the limit on IA64. Increase the maximum size of the IA64 per cpu area
> > from 64K to 128K.
> >
> > -#define PERCPU_PAGE_SHIFT 16 /* log2() of max. size of per-CPU area */
> > +#define PERCPU_PAGE_SHIFT 17 /* log2() of max. size of per-CPU area */
>
> Don't you need some more changes to the alt_dtlb_miss handler in
> ivt.S for this to work? 128K is not a supported pagesize on any
> processor model.

Yes, this was one of the issues with IA64 and extending the per-cpu area.
It's probable that the IA64 TLB nailing trick might have to give way for
dynamic per-cpu...

Rusty.