sched: convert idle_balance() to cpumask_var_t.
Impact: stack usage reduction
Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space in the stack. cpumask_var_t is just a struct cpumask for
!CONFIG_CPUMASK_OFFSTACK.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 2f8ea99..154a95f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3676,7 +3676,10 @@
struct sched_domain *sd;
int pulled_task = -1;
unsigned long next_balance = jiffies + HZ;
- cpumask_t tmpmask;
+ cpumask_var_t tmpmask;
+
+ if (!alloc_cpumask_var(&tmpmask, GFP_ATOMIC))
+ return;
for_each_domain(this_cpu, sd) {
unsigned long interval;
@@ -3687,7 +3690,7 @@
if (sd->flags & SD_BALANCE_NEWIDLE)
/* If we've pulled tasks over stop searching: */
pulled_task = load_balance_newidle(this_cpu, this_rq,
- sd, &tmpmask);
+ sd, tmpmask);
interval = msecs_to_jiffies(sd->balance_interval);
if (time_after(next_balance, sd->last_balance + interval))
@@ -3702,6 +3705,7 @@
*/
this_rq->next_balance = next_balance;
}
+ free_cpumask_var(tmpmask);
}
/*