Re: [PATCH UPDATED] percpu: use dynamic percpu allocator as the default percpu allocator

Ingo Molnar
2009-04-01T15:54:26Z

* Christoph Lameter <cl@linux.com> wrote:

> On Wed, 1 Apr 2009, Tejun Heo wrote:
>
> > > 1. Lot of unnecessary use of __read_mostly for local static variables that
> > > are not on the hotpath. Patch follows in this message.
> >
> > Hmmm... Those are basically read-only vars once initialization is
> > complete. IIUC, __read_mostly just puts the tagged variables into a
> > separate segment so that they don't have to worry about cacheline
> > bouncing. Is there any reason to remove __read_mostly? Or is it just
> > that it's mostly superflous?
>
> Yes its better for the variables to be all together if its not on hot
> cache paths. And its better to keep the __read_mostly segment reserved for
> frequently accessed variables.

We need __access_rarely i guess.

Ingo