cpumask: reduce stack usage in find_lowest_rq
Impact: reduce stack usage, cleanup
Use a cpumask_var_t in find_lowest_rq() and clean up other old
cpumask_t calls.
Signed-off-by: Mike Travis <travis@sgi.com>
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 954e1a8..da932f4 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -960,16 +960,17 @@
static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
-static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
+static inline int pick_optimal_cpu(int this_cpu,
+ const struct cpumask *mask)
{
int first;
/* "this_cpu" is cheaper to preempt than a remote processor */
- if ((this_cpu != -1) && cpu_isset(this_cpu, *mask))
+ if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask))
return this_cpu;
- first = first_cpu(*mask);
- if (first != NR_CPUS)
+ first = cpumask_first(mask);
+ if (first < nr_cpu_ids)
return first;
return -1;
@@ -981,6 +982,7 @@
struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
+ cpumask_var_t domain_mask;
if (task->rt.nr_cpus_allowed == 1)
return -1; /* No other targets possible */
@@ -1013,19 +1015,25 @@
if (this_cpu == cpu)
this_cpu = -1; /* Skip this_cpu opt if the same */
- for_each_domain(cpu, sd) {
- if (sd->flags & SD_WAKE_AFFINE) {
- cpumask_t domain_mask;
- int best_cpu;
+ if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) {
+ for_each_domain(cpu, sd) {
+ if (sd->flags & SD_WAKE_AFFINE) {
+ int best_cpu;
- cpumask_and(&domain_mask, sched_domain_span(sd),
- lowest_mask);
+ cpumask_and(domain_mask,
+ sched_domain_span(sd),
+ lowest_mask);
- best_cpu = pick_optimal_cpu(this_cpu,
- &domain_mask);
- if (best_cpu != -1)
- return best_cpu;
+ best_cpu = pick_optimal_cpu(this_cpu,
+ domain_mask);
+
+ if (best_cpu != -1) {
+ free_cpumask_var(domain_mask);
+ return best_cpu;
+ }
+ }
}
+ free_cpumask_var(domain_mask);
}
/*