Messages in this thread | | | Date | Tue, 16 Apr 2024 10:45:53 -0700 | From | Yury Norov <> | Subject | Re: [PATCH v2 1/7] cpumask: introduce cpumask_first_and_and() |
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On Tue, Apr 16, 2024 at 04:54:48PM +0800, Dawei Li wrote: > Introduce cpumask_first_and_and() to get intersection between 3 cpumasks, > free of any intermediate cpumask variable. Instead, cpumask_first_and_and() > works in-place with all inputs and produce desired output directly. > > Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Acked-by: Yury Norov <yury.norov@gmail.com>
> --- > include/linux/cpumask.h | 17 +++++++++++++++++ > include/linux/find.h | 27 +++++++++++++++++++++++++++ > lib/find_bit.c | 12 ++++++++++++ > 3 files changed, 56 insertions(+) > > diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h > index 1c29947db848..c46f9e9e1d66 100644 > --- a/include/linux/cpumask.h > +++ b/include/linux/cpumask.h > @@ -187,6 +187,23 @@ unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask > return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits); > } > > +/** > + * cpumask_first_and_and - return the first cpu from *srcp1 & *srcp2 & *srcp3 > + * @srcp1: the first input > + * @srcp2: the second input > + * @srcp3: the third input > + * > + * Return: >= nr_cpu_ids if no cpus set in all. > + */ > +static inline > +unsigned int cpumask_first_and_and(const struct cpumask *srcp1, > + const struct cpumask *srcp2, > + const struct cpumask *srcp3) > +{ > + return find_first_and_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), > + cpumask_bits(srcp3), small_cpumask_bits); > +} > + > /** > * cpumask_last - get the last CPU in a cpumask > * @srcp: - the cpumask pointer > diff --git a/include/linux/find.h b/include/linux/find.h > index c69598e383c1..28ec5a03393a 100644 > --- a/include/linux/find.h > +++ b/include/linux/find.h > @@ -29,6 +29,8 @@ unsigned long __find_nth_and_andnot_bit(const unsigned long *addr1, const unsign > unsigned long n); > extern unsigned long _find_first_and_bit(const unsigned long *addr1, > const unsigned long *addr2, unsigned long size); > +unsigned long _find_first_and_and_bit(const unsigned long *addr1, const unsigned long *addr2, > + const unsigned long *addr3, unsigned long size); > extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size); > extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size); > > @@ -345,6 +347,31 @@ unsigned long find_first_and_bit(const unsigned long *addr1, > } > #endif > > +/** > + * find_first_and_and_bit - find the first set bit in 3 memory regions > + * @addr1: The first address to base the search on > + * @addr2: The second address to base the search on > + * @addr3: The third address to base the search on > + * @size: The bitmap size in bits > + * > + * Returns the bit number for the first set bit > + * If no bits are set, returns @size. > + */ > +static inline > +unsigned long find_first_and_and_bit(const unsigned long *addr1, > + const unsigned long *addr2, > + const unsigned long *addr3, > + unsigned long size) > +{ > + if (small_const_nbits(size)) { > + unsigned long val = *addr1 & *addr2 & *addr3 & GENMASK(size - 1, 0); > + > + return val ? __ffs(val) : size; > + } > + > + return _find_first_and_and_bit(addr1, addr2, addr3, size); > +} > + > #ifndef find_first_zero_bit > /** > * find_first_zero_bit - find the first cleared bit in a memory region > diff --git a/lib/find_bit.c b/lib/find_bit.c > index 32f99e9a670e..dacadd904250 100644 > --- a/lib/find_bit.c > +++ b/lib/find_bit.c > @@ -116,6 +116,18 @@ unsigned long _find_first_and_bit(const unsigned long *addr1, > EXPORT_SYMBOL(_find_first_and_bit); > #endif > > +/* > + * Find the first set bit in three memory regions. > + */ > +unsigned long _find_first_and_and_bit(const unsigned long *addr1, > + const unsigned long *addr2, > + const unsigned long *addr3, > + unsigned long size) > +{ > + return FIND_FIRST_BIT(addr1[idx] & addr2[idx] & addr3[idx], /* nop */, size); > +} > +EXPORT_SYMBOL(_find_first_and_and_bit); > + > #ifndef find_first_zero_bit > /* > * Find the first cleared bit in a memory region. > -- > 2.27.0
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