sched/rt: Further simplify pick_rt_task()

Function next_prio() has been removed and pull_rt_task() is the
only user of pick_next_highest_task_rt() at the moment.

pull_rt_task is not interested in p->nr_cpus_allowed, its only
interest is the fact that cpu is allowed to execute p. If
nr_cpus_allowed == 1, cpu != task_cpu(p) and cpu is allowed then
it means that task p is in the middle of the migration
techniques; the task waits until it is moved by migration
thread. So, lets pull it earlier.

Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
CC: linux-rt-users <linux-rt-users@vger.kernel.org>
Link: http://lkml.kernel.org/r/70871359644177@web16d.yandex.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 94abca4d9cf57198383a10ee4fcb1982f3e71000..c25de141c57658ab3a95c6d5e27edafb0869db7f 100644 (file)
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1427,8 +1427,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
        if (!task_running(rq, p) &&
-           (cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&
-           (p->nr_cpus_allowed > 1))
+           cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
                return 1;
        return 0;
 }