Re: [patch 04/41] cpu ops: Core piece for generic atomic per cpu operations

[Rusty Russell]

On Tuesday 17 June 2008 00:52:08 Christoph Lameter wrote:
> On Sun, 15 Jun 2008, Rusty Russell wrote:
> > > 3. Some hooks for arches to override particular behavior as needed.
> > >    F.e. IA64 allocates percpu structures in a special way. x86_64
> > >    needs to do some tricks for the pda etc etc.
> >
> > IA64 is going to need some work, since dynamic percpu addresses won't be
> > able to use their pinned TLB trick to get the local version.
>
> The ia64 hook could simply return the address of percpu area that
> was reserved when the per node memory layout was generated (which happens
> very early during node bootstrap).

Apologies, this time I read the code.  I thought IA64 used the pinned TLB area 
to access per-cpu vars under some circumstances, but they only do that via an 
arch-specific macro.

So creating new congruent mappings to expand the percpu area(s) is our main 
concern now?

Rusty.
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