Re: [RFC PATCH 2/5] cpumask: Implement cpumask_{first,next}_{not,}andnot

[Mathieu Desnoyers]

On 2024-08-19 21:24, Yury Norov wrote:
> On Mon, Aug 19, 2024 at 04:24:03PM +0200, Mathieu Desnoyers wrote:
> > Allow finding the first or next bit within two input cpumasks which is
> > either:
>
> "first or next CPU..." here.
>   
> > - both zero and zero,
> > - respectively one and zero.
> >
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> > Cc: Yury Norov <yury.norov@xxxxxxxxx>
> > Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> > ---
> >   include/linux/cpumask.h | 60 +++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 60 insertions(+)
> >
> > diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
> > index 23686bed441d..57b7d99d6da1 100644
> > --- a/include/linux/cpumask.h
> > +++ b/include/linux/cpumask.h
> > @@ -204,6 +204,32 @@ unsigned int cpumask_first_and_and(const struct cpumask *srcp1,
> >   				      cpumask_bits(srcp3), small_cpumask_bits);
> >   }
> >   
> > +/**
> > + * cpumask_first_andnot - return the first cpu from *srcp1 & ~*srcp2
> > + * @src1p: the first input
> > + * @src2p: the second input
> > + *
> > + * Returns >= nr_cpu_ids if no cpus match in both.
> > + */
> > +static inline
> > +unsigned int cpumask_first_andnot(const struct cpumask *srcp1, const struct cpumask *srcp2)
>
> Please use __always_inline to enforce a compile-time optimizations.
> Check for this series:
> https://lore.kernel.org/lkml/20240719005127.2449328-4-briannorris@xxxxxxxxxxxx/T/

I'll use __always_inline in both bitmap and cpumask patches.

I'll update this patch to rename notandnot to zero_and.

Thanks,

Mathieu

> It's already in -next.
>
> Thanks,
> Yury
>
> > +{
> > +	return find_first_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
> > +}
> > +
> > +/**
> > + * cpumask_first_notandnot - return the first cpu from ~*srcp1 & ~*srcp2
> > + * @src1p: the first input
> > + * @src2p: the second input
> > + *
> > + * Returns >= nr_cpu_ids if no cpus match in both.
> > + */
> > +static inline
> > +unsigned int cpumask_first_notandnot(const struct cpumask *srcp1, const struct cpumask *srcp2)
> > +{
> > +	return find_first_notandnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
> > +}
> > +
> >   /**
> >    * cpumask_last - get the last CPU in a cpumask
> >    * @srcp:	- the cpumask pointer
> > @@ -246,6 +272,40 @@ 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 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), nr_cpumask_bits, n+1);
> > +}
> > +
> > +/**
> > + * cpumask_next_notandnot - 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 inline
> > +unsigned int cpumask_next_notandnot(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_notandnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_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