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| author | Shrikanth Hegde <sshegde@linux.ibm.com> | 2026-09-28 11:07:17 +0530 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-09-28 08:44:40 +0200 |
| commit | cfb463b7172dca2f29b2221b71b54890f268e3fb (patch) | |
| tree | fad688fd210e231fc9d322b5ac56f787e7639ffa /include/linux/bitmap.h | |
| parent | a8d0854a76a876ea474e17322acb680716a09da2 (diff) | |
| download | linux-next-cfb463b7172dca2f29b2221b71b54890f268e3fb.tar.gz linux-next-cfb463b7172dca2f29b2221b71b54890f268e3fb.zip | |
cpumask: Introduce cpumask_intersects_and
Introduce bitmap_intersects_and() to determine whether the intersection
of three bitmaps is non-empty. Unlike cpumask_first_and_and(), this
returns immediately when an intersecting word is found and does not
calculate the first matching bit.
Add cpumask_intersects_and() as the corresponding cpumask wrapper.
A subsequent patch uses the helper to determine whether a task
has a CPU that is present in its affinity mask, the preferred CPU mask,
and task possible CPU mask.
Suggested-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviwed-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Link: https://patch.msgid.link/20260928053728.797539-3-sshegde@linux.ibm.com
Diffstat (limited to 'include/linux/bitmap.h')
| -rw-r--r-- | include/linux/bitmap.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 7df1573a409c..adafbcf2016b 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -52,6 +52,7 @@ struct device; * bitmap_complement(dst, src, nbits) *dst = ~(*src) * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? + * bitmap_intersects_and(src1, src2, src3, nbits) Do *src1, *src2 and *src3 overlap? * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? * bitmap_empty(src, nbits) Are all bits zero in *src? * bitmap_full(src, nbits) Are all bits set in *src? @@ -181,6 +182,9 @@ void __bitmap_replace(unsigned long *dst, const unsigned long *mask, unsigned int nbits); bool __bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); +bool __bitmap_intersects_and(const unsigned long *bitmap1, + const unsigned long *bitmap2, + const unsigned long *bitmap3, unsigned int nbits); 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); @@ -446,6 +450,16 @@ bool bitmap_intersects(const unsigned long *src1, const unsigned long *src2, uns } static __always_inline +bool bitmap_intersects_and(const unsigned long *src1, const unsigned long *src2, + const unsigned long *src3, unsigned int nbits) +{ + if (small_const_nbits(nbits)) + return ((*src1 & *src2 & *src3) & BITMAP_LAST_WORD_MASK(nbits)) != 0; + else + return __bitmap_intersects_and(src1, src2, src3, nbits); +} + +static __always_inline bool bitmap_subset(const unsigned long *src1, const unsigned long *src2, unsigned int nbits) { if (small_const_nbits(nbits)) |