Messages in this thread | | | Subject | Re: [PATCH v4 1/5] powerpc/mm/slice: Remove intermediate bitmap copy | From | Christophe LEROY <> | Date | Sat, 10 Feb 2018 15:57:25 +0100 |
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Le 10/02/2018 à 15:43, Nicholas Piggin a écrit : > 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.
Thanks,
I had a quick look at your serie, it looks promising.
The main purpose of mine is to allow the use of slies on the 8xx in order to fix a hugepage related bug.
Your serie is performance oriented and seems nice, indeed I should have noticed that it was passing huge structures instead of pointers to subfunctions. I will look at your serie more in details next week.
Christophe
> > 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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