Commit 5f75ff29 authored by Valentin Schneider's avatar Valentin Schneider Committed by Yury Norov
Browse files

cpumask: Introduce for_each_cpu_andnot() 



for_each_cpu_and() is very convenient as it saves having to allocate a
temporary cpumask to store the result of cpumask_and(). The same issue
applies to cpumask_andnot() which doesn't actually need temporary storage
for iteration purposes.

Following what has been done for for_each_cpu_and(), introduce
for_each_cpu_andnot().

Signed-off-by: default avatarValentin Schneider <vschneid@redhat.com>
parent 90d48290

include/linux/cpumask.h

+18 −0
Original line number Diff line number Diff line
@@ -306,6 +306,24 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta 
#define for_each_cpu_and(cpu, mask1, mask2)				\

	for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits)



/**

 * for_each_cpu_andnot - iterate over every cpu present in one mask, excluding

 *			 those present in another.

 * @cpu: the (optionally unsigned) integer iterator

 * @mask1: the first cpumask pointer

 * @mask2: the second cpumask pointer

 *

 * This saves a temporary CPU mask in many places.  It is equivalent to:

 *	struct cpumask tmp;

 *	cpumask_andnot(&tmp, &mask1, &mask2);

 *	for_each_cpu(cpu, &tmp)

 *		...

 *

 * After the loop, cpu is >= nr_cpu_ids.

 */

#define for_each_cpu_andnot(cpu, mask1, mask2)				\

	for_each_andnot_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits)



/**

 * cpumask_any_but - return a "random" in a cpumask, but not this one.

 * @mask: the cpumask to search

include/linux/find.h

+5 −0
Original line number Diff line number Diff line
@@ -498,6 +498,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned 
	     (bit) = find_next_and_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\

	     (bit)++)



#define for_each_andnot_bit(bit, addr1, addr2, size) \

	for ((bit) = 0;									\

	     (bit) = find_next_andnot_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\

	     (bit)++)



/* same as for_each_set_bit() but use bit as value to start with */

#define for_each_set_bit_from(bit, addr, size) \

	for (; (bit) = find_next_bit((addr), (size), (bit)), (bit) < (size); (bit)++)