From 24291caf8447f6fc060c8d00136bdc30ee207f38 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sat, 17 Sep 2022 20:07:12 -0700 Subject: lib/bitmap: add bitmap_weight_and() The function calculates Hamming weight of (bitmap1 & bitmap2). Now we have to do like this: tmp = bitmap_alloc(nbits); bitmap_and(tmp, map1, map2, nbits); weight = bitmap_weight(tmp, nbits); bitmap_free(tmp); This requires additional memory, adds pressure on alloc subsystem, and way less cache-friendly than just: weight = bitmap_weight_and(map1, map2, nbits); The following patches apply it for cpumask functions. Signed-off-by: Yury Norov --- include/linux/bitmap.h | 12 ++++++++++++ include/linux/cpumask.h | 11 +++++++++++ 2 files changed, 23 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index f65410a49fda..b2aef45af0db 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -51,6 +51,7 @@ struct device; * bitmap_empty(src, nbits) Are all bits zero in *src? * bitmap_full(src, nbits) Are all bits set in *src? * bitmap_weight(src, nbits) Hamming Weight: number set bits + * bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap * bitmap_set(dst, pos, nbits) Set specified bit area * bitmap_clear(dst, pos, nbits) Clear specified bit area * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area @@ -164,6 +165,8 @@ bool __bitmap_intersects(const unsigned long *bitmap1, bool __bitmap_subset(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); +unsigned int __bitmap_weight_and(const unsigned long *bitmap1, + const unsigned long *bitmap2, unsigned int nbits); void __bitmap_set(unsigned long *map, unsigned int start, int len); void __bitmap_clear(unsigned long *map, unsigned int start, int len); @@ -439,6 +442,15 @@ unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits) return __bitmap_weight(src, nbits); } +static __always_inline +unsigned long bitmap_weight_and(const unsigned long *src1, + const unsigned long *src2, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)); + return __bitmap_weight_and(src1, src2, nbits); +} + static __always_inline void bitmap_set(unsigned long *map, unsigned int start, unsigned int nbits) { diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 1b442fb2001f..9a71af8097ca 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -586,6 +586,17 @@ static inline unsigned int cpumask_weight(const struct cpumask *srcp) return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits); } +/** + * cpumask_weight_and - Count of bits in (*srcp1 & *srcp2) + * @srcp1: the cpumask to count bits (< nr_cpu_ids) in. + * @srcp2: the cpumask to count bits (< nr_cpu_ids) in. + */ +static inline unsigned int cpumask_weight_and(const struct cpumask *srcp1, + const struct cpumask *srcp2) +{ + return bitmap_weight_and(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits); +} + /** * cpumask_shift_right - *dstp = *srcp >> n * @dstp: the cpumask result -- cgit v1.2.3-59-g8ed1b