cpumask: add a few comments of cpumask functions
Current few cpumask functions' purposes are not quite clear. Stupid
user like myself needs to dig into details for clear function
purpose and return value.
Add few explanation for them is helpful.
Thanks for Srivatsa's comments and correction!
Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index a2c819d..8bf1c27 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -272,6 +272,8 @@
* @cpu: cpu number (< nr_cpu_ids)
* @cpumask: the cpumask pointer
*
+ * Returns 1 if @cpu is set in @cpumask, else returns 0
+ *
* No static inline type checking - see Subtlety (1) above.
*/
#define cpumask_test_cpu(cpu, cpumask) \
@@ -282,6 +284,8 @@
* @cpu: cpu number (< nr_cpu_ids)
* @cpumask: the cpumask pointer
*
+ * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
+ *
* test_and_set_bit wrapper for cpumasks.
*/
static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
@@ -294,6 +298,8 @@
* @cpu: cpu number (< nr_cpu_ids)
* @cpumask: the cpumask pointer
*
+ * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
+ *
* test_and_clear_bit wrapper for cpumasks.
*/
static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
@@ -324,6 +330,8 @@
* @dstp: the cpumask result
* @src1p: the first input
* @src2p: the second input
+ *
+ * If *@dstp is empty, returns 0, else returns 1
*/
static inline int cpumask_and(struct cpumask *dstp,
const struct cpumask *src1p,
@@ -365,6 +373,8 @@
* @dstp: the cpumask result
* @src1p: the first input
* @src2p: the second input
+ *
+ * If *@dstp is empty, returns 0, else returns 1
*/
static inline int cpumask_andnot(struct cpumask *dstp,
const struct cpumask *src1p,
@@ -414,6 +424,8 @@
* cpumask_subset - (*src1p & ~*src2p) == 0
* @src1p: the first input
* @src2p: the second input
+ *
+ * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
*/
static inline int cpumask_subset(const struct cpumask *src1p,
const struct cpumask *src2p)