Messages in this thread | | | Date | Sun, 11 Feb 2018 00:43:09 +1000 | From | Nicholas Piggin <> | Subject | Re: [PATCH v4 1/5] powerpc/mm/slice: Remove intermediate bitmap copy |
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On Sat, 10 Feb 2018 13:54:25 +0100 (CET) Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> bitmap_or() and bitmap_andnot() can work properly with dst identical > to src1 or src2. There is no need of an intermediate result bitmap > that is copied back to dst in a second step.
Everyone seems to be working on the slice code all of a sudden. I had the same change in my series I just posted, but I didn't notice this one of yours earlier, and it's better split out, so this is fine by me.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
> > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > --- > v2: New in v2 > v3: patch moved up front of the serie to avoid ephemeral slice_bitmap_copy() function in following patch > v4: No change > > arch/powerpc/mm/slice.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) > > diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c > index 23ec2c5e3b78..98b53d48968f 100644 > --- a/arch/powerpc/mm/slice.c > +++ b/arch/powerpc/mm/slice.c > @@ -388,21 +388,17 @@ static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len, > > static inline void slice_or_mask(struct slice_mask *dst, struct slice_mask *src) > { > - DECLARE_BITMAP(result, SLICE_NUM_HIGH); > - > dst->low_slices |= src->low_slices; > - bitmap_or(result, dst->high_slices, src->high_slices, SLICE_NUM_HIGH); > - bitmap_copy(dst->high_slices, result, SLICE_NUM_HIGH); > + bitmap_or(dst->high_slices, dst->high_slices, src->high_slices, > + SLICE_NUM_HIGH); > } > > static inline void slice_andnot_mask(struct slice_mask *dst, struct slice_mask *src) > { > - DECLARE_BITMAP(result, SLICE_NUM_HIGH); > - > dst->low_slices &= ~src->low_slices; > > - bitmap_andnot(result, dst->high_slices, src->high_slices, SLICE_NUM_HIGH); > - bitmap_copy(dst->high_slices, result, SLICE_NUM_HIGH); > + bitmap_andnot(dst->high_slices, dst->high_slices, src->high_slices, > + SLICE_NUM_HIGH); > } > > #ifdef CONFIG_PPC_64K_PAGES
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