| Message ID | 20210719021755.883182-2-yury.norov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bitmap: unify for_each_bit() macros | expand |
Hello, On Sun, Jul 18, 2021 at 07:17:52PM -0700, Yury Norov wrote: > bitmap_next_clear_region() calls find_next_zero_bit() and find_next_bit() > sequentially to find a range of clear bits. In case of pcpu_is_populated() > there's a chance to return earlier if bitmap has all bits set. > > Signed-off-by: Yury Norov <yury.norov@gmail.com> > --- > mm/percpu.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/mm/percpu.c b/mm/percpu.c > index 7f2e0151c4e2..25461571dcc5 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -1071,17 +1071,18 @@ static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, > static bool pcpu_is_populated(struct pcpu_chunk *chunk, int bit_off, int bits, > int *next_off) > { > - unsigned int page_start, page_end, rs, re; > + unsigned int start, end; > > - page_start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); > - page_end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); > + start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); > + end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); > > - rs = page_start; > - bitmap_next_clear_region(chunk->populated, &rs, &re, page_end); > - if (rs >= page_end) > + start = find_next_zero_bit(chunk->populated, end, start); > + if (start >= end) > return true; > > - *next_off = re * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; > + end = find_next_bit(chunk->populated, end, start + 1); > + > + *next_off = end * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; > return false; > } > > -- > 2.30.2 > Sorry for the delay. Acked-by: Dennis Zhou <dennis@kernel.org> Thanks, Dennis
diff --git a/mm/percpu.c b/mm/percpu.c index 7f2e0151c4e2..25461571dcc5 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1071,17 +1071,18 @@ static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, static bool pcpu_is_populated(struct pcpu_chunk *chunk, int bit_off, int bits, int *next_off) { - unsigned int page_start, page_end, rs, re; + unsigned int start, end; - page_start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); - page_end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); + start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); + end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); - rs = page_start; - bitmap_next_clear_region(chunk->populated, &rs, &re, page_end); - if (rs >= page_end) + start = find_next_zero_bit(chunk->populated, end, start); + if (start >= end) return true; - *next_off = re * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; + end = find_next_bit(chunk->populated, end, start + 1); + + *next_off = end * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; return false; }
bitmap_next_clear_region() calls find_next_zero_bit() and find_next_bit() sequentially to find a range of clear bits. In case of pcpu_is_populated() there's a chance to return earlier if bitmap has all bits set. Signed-off-by: Yury Norov <yury.norov@gmail.com> --- mm/percpu.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)