sched: Keep kthreads at default priority

Removes kthread/workqueue priority boost, they increase worst-case
desktop latencies.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1252486344.28645.18.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/kthread.c b/kernel/kthread.c
index eb8751a..5fe7099 100644 (file)
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -16,8 +16,6 @@
 #include <linux/mutex.h>
 #include <trace/events/sched.h>
 
-#define KTHREAD_NICE_LEVEL (-5)
-
 static DEFINE_SPINLOCK(kthread_create_lock);
 static LIST_HEAD(kthread_create_list);
 struct task_struct *kthreadd_task;
@@ -145,7 +143,6 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
                 * The kernel thread should not inherit these properties.
                 */
                sched_setscheduler_nocheck(create.result, SCHED_NORMAL, &param);
-               set_user_nice(create.result, KTHREAD_NICE_LEVEL);
                set_cpus_allowed_ptr(create.result, cpu_all_mask);
        }
        return create.result;
@@ -221,7 +218,6 @@ int kthreadd(void *unused)
        /* Setup a clean context for our children to inherit. */
        set_task_comm(tsk, "kthreadd");
        ignore_signals(tsk);
-       set_user_nice(tsk, KTHREAD_NICE_LEVEL);
        set_cpus_allowed_ptr(tsk, cpu_all_mask);
        set_mems_allowed(node_possible_map);
 

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0668795..ea1b4e7 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -317,8 +317,6 @@ static int worker_thread(void *__cwq)
        if (cwq->wq->freezeable)
                set_freezable();
 
-       set_user_nice(current, -5);
-
        for (;;) {
                prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
                if (!freezing(current) &&