lkml.org 
[lkml]   [2024]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 1/7] cpumask: introduce cpumask_first_and_and()
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

\
 
 \ /
  Last update: 2024-04-16 19:46    [W:0.045 / U:1.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site