sched: convert sched_domain_debug to cpumask_var_t.

Impact: stack usage reduction

Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
stack space.  cpumask_var_t is just a struct cpumask for
!CONFIG_CPUMASK_OFFSTACK.

In this case, we always alloced, but we don't need to any more.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 4 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 2d4ff91e0c97..24012c2a8892 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6706,7 +6706,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 
 static void sched_domain_debug(struct sched_domain *sd, int cpu)
 {
-        cpumask_t *groupmask;
+        cpumask_var_t groupmask;
         int level = 0;
 
         if (!sd) {
@@ -6716,8 +6716,7 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
 
         printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
 
-        groupmask = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
-        if (!groupmask) {
+        if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) {
                 printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
                 return;
         }
@@ -6730,7 +6729,7 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
                 if (!sd)
                         break;
         }
-        kfree(groupmask);
+        free_cpumask_var(groupmask);
 }
 #else /* !CONFIG_SCHED_DEBUG */
 # define sched_domain_debug(sd, cpu) do { } while (0)