sched_rt: don't allocate cpumask in fastpath
Impact: cleanup
As pointed out by Steven Rostedt. Since the arg in question is
unused, we simply change cpupri_find() to accept NULL.
Reported-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <200903251501.22664.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index 1e00bfa..cdd3c89 100644
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -55,7 +55,7 @@
* cpupri_find - find the best (lowest-pri) CPU in the system
* @cp: The cpupri context
* @p: The task
- * @lowest_mask: A mask to fill in with selected CPUs
+ * @lowest_mask: A mask to fill in with selected CPUs (or NULL)
*
* Note: This function returns the recommended CPUs as calculated during the
* current invokation. By the time the call returns, the CPUs may have in
@@ -81,7 +81,8 @@
if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
continue;
- cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
+ if (lowest_mask)
+ cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
return 1;
}
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index bac1061..fbec5a5 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -805,20 +805,15 @@
static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
{
- cpumask_var_t mask;
-
if (rq->curr->rt.nr_cpus_allowed == 1)
return;
- if (!alloc_cpumask_var(&mask, GFP_ATOMIC))
+ if (p->rt.nr_cpus_allowed != 1
+ && cpupri_find(&rq->rd->cpupri, p, NULL))
return;
- if (p->rt.nr_cpus_allowed != 1
- && cpupri_find(&rq->rd->cpupri, p, mask))
- goto free;
-
- if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask))
- goto free;
+ if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
+ return;
/*
* There appears to be other cpus that can accept
@@ -827,8 +822,6 @@
*/
requeue_task_rt(rq, p, 1);
resched_task(rq->curr);
-free:
- free_cpumask_var(mask);
}
#endif /* CONFIG_SMP */
