Re: [RFC REBASED 4/5] powerpc/mm/slice: Use const pointers to cached slice masks where possible

From: Nicholas Piggin
Date: Tue Feb 27 2018 - 04:08:37 EST


On Tue, 27 Feb 2018 12:59:53 +0530
"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> wrote:

> Christophe Leroy <christophe.leroy@xxxxxx> writes:
>
> > The slice_mask cache was a basic conversion which copied the slice
> > mask into caller's structures, because that's how the original code
> > worked. In most cases the pointer can be used directly instead, saving
> > a copy and an on-stack structure.
> >
> > This also converts the slice_mask bit operation helpers to be the usual
> > 3-operand kind, which is clearer to work with. And we remove some
> > unnecessary intermediate bitmaps, reducing stack and copy overhead
> > further.
>
> Can we move the reduce unncessary intermediate bitmaps as another patch?

This was rightly split out -- it moved to Christophe's patch he already
made in his series. The changelog can just be adjusted.

Thanks,
Nick