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

Christoph Lameter
2009-04-01T13:55:35Z

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.