Commit 944c417d authored by Yury Norov's avatar Yury Norov
Browse files

cpumask: add cpumask_nth_{,and,andnot} 



Add cpumask_nth_{,and,andnot} as wrappers around corresponding
find functions, and use it in cpumask_local_spread().

Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
parent 97848c10

include/linux/cpumask.h

+44 −0
Original line number Diff line number Diff line
@@ -337,6 +337,50 @@ unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) 
	return i;

}



/**

 * cpumask_nth - get the first cpu in a cpumask

 * @srcp: the cpumask pointer

 * @cpu: the N'th cpu to find, starting from 0

 *

 * Returns >= nr_cpu_ids if such cpu doesn't exist.

 */

static inline unsigned int cpumask_nth(unsigned int cpu, const struct cpumask *srcp)

{

	return find_nth_bit(cpumask_bits(srcp), nr_cpumask_bits, cpumask_check(cpu));

}



/**

 * cpumask_nth_and - get the first cpu in 2 cpumasks

 * @srcp1: the cpumask pointer

 * @srcp2: the cpumask pointer

 * @cpu: the N'th cpu to find, starting from 0

 *

 * Returns >= nr_cpu_ids if such cpu doesn't exist.

 */

static inline

unsigned int cpumask_nth_and(unsigned int cpu, const struct cpumask *srcp1,

							const struct cpumask *srcp2)

{

	return find_nth_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2),

				nr_cpumask_bits, cpumask_check(cpu));

}



/**

 * cpumask_nth_andnot - get the first cpu set in 1st cpumask, and clear in 2nd.

 * @srcp1: the cpumask pointer

 * @srcp2: the cpumask pointer

 * @cpu: the N'th cpu to find, starting from 0

 *

 * Returns >= nr_cpu_ids if such cpu doesn't exist.

 */

static inline

unsigned int cpumask_nth_andnot(unsigned int cpu, const struct cpumask *srcp1,

							const struct cpumask *srcp2)

{

	return find_nth_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2),

				nr_cpumask_bits, cpumask_check(cpu));

}



#define CPU_BITS_NONE						\

{								\

	[0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL			\

lib/cpumask.c

+13 −15
Original line number Diff line number Diff line
@@ -128,24 +128,22 @@ unsigned int cpumask_local_spread(unsigned int i, int node) 
	i %= num_online_cpus();



	if (node == NUMA_NO_NODE) {

		for_each_cpu(cpu, cpu_online_mask)

			if (i-- == 0)

		cpu = cpumask_nth(i, cpu_online_mask);

		if (cpu < nr_cpu_ids)

			return cpu;

	} else {

		/* NUMA first. */

		for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask)

			if (i-- == 0)

		cpu = cpumask_nth_and(i, cpu_online_mask, cpumask_of_node(node));

		if (cpu < nr_cpu_ids)

			return cpu;



		for_each_cpu(cpu, cpu_online_mask) {

			/* Skip NUMA nodes, done above. */

			if (cpumask_test_cpu(cpu, cpumask_of_node(node)))

				continue;

		i -= cpumask_weight_and(cpu_online_mask, cpumask_of_node(node));



			if (i-- == 0)

		/* Skip NUMA nodes, done above. */

		cpu = cpumask_nth_andnot(i, cpu_online_mask, cpumask_of_node(node));

		if (cpu < nr_cpu_ids)

			return cpu;

	}

	}

	BUG();

}

EXPORT_SYMBOL(cpumask_local_spread);