Allow finding the next bit within two input cpumasks which is
respectively one and zero.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/cpumask.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 23686bed441d..5da1c66cfa65 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -246,6 +246,23 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 	return find_next_zero_bit(cpumask_bits(srcp), small_cpumask_bits, n+1);
 }
 
+/**
+ * cpumask_next_andnot - return the next cpu from *srcp1 & ~*srcp2
+ * @n: the cpu prior to the place to search (ie. return will be > @n)
+ * @src1p: the first input
+ * @src2p: the second input
+ *
+ * Returns >= nr_cpu_ids if no cpus match in both.
+ */
+static __always_inline
+unsigned int cpumask_next_andnot(int n, const struct cpumask *srcp1, const struct cpumask *srcp2)
+{
+	/* -1 is a legal arg here. */
+	if (n != -1)
+		cpumask_check(n);
+	return find_next_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits, n+1);
+}
+
 #if NR_CPUS == 1
 /* Uniprocessor: there is only one valid CPU */
 static inline unsigned int cpumask_local_spread(unsigned int i, int node)
-- 
2.39.2

On Tue, Sep 03, 2024 at 03:06:49PM -0400, Mathieu Desnoyers wrote:
> Allow finding the next bit within two input cpumasks which is
> respectively one and zero.
> 
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Yury Norov <yury.norov@gmail.com>
> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>

Acked-by: Yury Norov <yury.norov@gmail.com>

> ---
>  include/linux/cpumask.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
> index 23686bed441d..5da1c66cfa65 100644
> --- a/include/linux/cpumask.h
> +++ b/include/linux/cpumask.h
> @@ -246,6 +246,23 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
>  	return find_next_zero_bit(cpumask_bits(srcp), small_cpumask_bits, n+1);
>  }
>  
> +/**
> + * cpumask_next_andnot - return the next cpu from *srcp1 & ~*srcp2
> + * @n: the cpu prior to the place to search (ie. return will be > @n)
> + * @src1p: the first input
> + * @src2p: the second input
> + *
> + * Returns >= nr_cpu_ids if no cpus match in both.
> + */
> +static __always_inline
> +unsigned int cpumask_next_andnot(int n, const struct cpumask *srcp1, const struct cpumask *srcp2)
> +{
> +	/* -1 is a legal arg here. */
> +	if (n != -1)
> +		cpumask_check(n);
> +	return find_next_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits, n+1);
> +}
> +
>  #if NR_CPUS == 1
>  /* Uniprocessor: there is only one valid CPU */
>  static inline unsigned int cpumask_local_spread(unsigned int i, int node)
> -- 
> 2.39.2

On 2024-09-03 15:28, Yury Norov wrote:
> On Tue, Sep 03, 2024 at 03:06:49PM -0400, Mathieu Desnoyers wrote:
>> Allow finding the next bit within two input cpumasks which is
>> respectively one and zero.
>>
>> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> Cc: Yury Norov <yury.norov@gmail.com>
>> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> 
> Acked-by: Yury Norov <yury.norov@gmail.com>

Thanks for the ack. However based on our discussion in the other
leg of this thread, I can simply use

+       for_each_cpu_andnot(cpu, cpumask, mm_allowed)
+               nr_set += !cpumask_test_and_set_cpu(cpu, mm_allowed);

which is already present in the API. I will drop this patch from
my series.

Thanks,

Mathieu

> 
>> ---
>>   include/linux/cpumask.h | 17 +++++++++++++++++
>>   1 file changed, 17 insertions(+)
>>
>> diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
>> index 23686bed441d..5da1c66cfa65 100644
>> --- a/include/linux/cpumask.h
>> +++ b/include/linux/cpumask.h
>> @@ -246,6 +246,23 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
>>   	return find_next_zero_bit(cpumask_bits(srcp), small_cpumask_bits, n+1);
>>   }
>>   
>> +/**
>> + * cpumask_next_andnot - return the next cpu from *srcp1 & ~*srcp2
>> + * @n: the cpu prior to the place to search (ie. return will be > @n)
>> + * @src1p: the first input
>> + * @src2p: the second input
>> + *
>> + * Returns >= nr_cpu_ids if no cpus match in both.
>> + */
>> +static __always_inline
>> +unsigned int cpumask_next_andnot(int n, const struct cpumask *srcp1, const struct cpumask *srcp2)
>> +{
>> +	/* -1 is a legal arg here. */
>> +	if (n != -1)
>> +		cpumask_check(n);
>> +	return find_next_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), small_cpumask_bits, n+1);
>> +}
>> +
>>   #if NR_CPUS == 1
>>   /* Uniprocessor: there is only one valid CPU */
>>   static inline unsigned int cpumask_local_spread(unsigned int i, int node)
>> -- 
>> 2.39.2

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com