Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "The main changes are:

   - lockless wakeup support for futexes and IPC message queues
     (Davidlohr Bueso, Peter Zijlstra)

   - Replace spinlocks with atomics in thread_group_cputimer(), to
     improve scalability (Jason Low)

   - NUMA balancing improvements (Rik van Riel)

   - SCHED_DEADLINE improvements (Wanpeng Li)

   - clean up and reorganize preemption helpers (Frederic Weisbecker)

   - decouple page fault disabling machinery from the preemption
     counter, to improve debuggability and robustness (David
     Hildenbrand)

   - SCHED_DEADLINE documentation updates (Luca Abeni)

   - topology CPU masks cleanups (Bartosz Golaszewski)

   - /proc/sched_debug improvements (Srikar Dronamraju)"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
  sched/deadline: Remove needless parameter in dl_runtime_exceeded()
  sched: Remove superfluous resetting of the p->dl_throttled flag
  sched/deadline: Drop duplicate init_sched_dl_class() declaration
  sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target
  sched/deadline: Make init_sched_dl_class() __init
  sched/deadline: Optimize pull_dl_task()
  sched/preempt: Add static_key() to preempt_notifiers
  sched/preempt: Fix preempt notifiers documentation about hlist_del() within unsafe iteration
  sched/stop_machine: Fix deadlock between multiple stop_two_cpus()
  sched/debug: Add sum_sleep_runtime to /proc/<pid>/sched
  sched/debug: Replace vruntime with wait_sum in /proc/sched_debug
  sched/debug: Properly format runnable tasks in /proc/sched_debug
  sched/numa: Only consider less busy nodes as numa balancing destinations
  Revert 095bebf61a46 ("sched/numa: Do not move past the balance point if unbalanced")
  sched/fair: Prevent throttling in early pick_next_task_fair()
  preempt: Reorganize the notrace definitions a bit
  preempt: Use preempt_schedule_context() as the official tracing preemption point
  sched: Make preempt_schedule_context() function-tracing safe
  x86: Remove cpu_sibling_mask() and cpu_core_mask()
  x86: Replace cpu_**_mask() with topology_**_cpumask()
  ...

1 files changed, 5 insertions, 37 deletions

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 695f0c6cd169..fd643d8c4b42 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -211,25 +211,6 @@ static int multi_cpu_stop(void *data)
 	return err;
 }
 
-struct irq_cpu_stop_queue_work_info {
-	int cpu1;
-	int cpu2;
-	struct cpu_stop_work *work1;
-	struct cpu_stop_work *work2;
-};
-
-/*
- * This function is always run with irqs and preemption disabled.
- * This guarantees that both work1 and work2 get queued, before
- * our local migrate thread gets the chance to preempt us.
- */
-static void irq_cpu_stop_queue_work(void *arg)
-{
-	struct irq_cpu_stop_queue_work_info *info = arg;
-	cpu_stop_queue_work(info->cpu1, info->work1);
-	cpu_stop_queue_work(info->cpu2, info->work2);
-}
-
 /**
  * stop_two_cpus - stops two cpus
  * @cpu1: the cpu to stop
@@ -245,7 +226,6 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 {
 	struct cpu_stop_done done;
 	struct cpu_stop_work work1, work2;
-	struct irq_cpu_stop_queue_work_info call_args;
 	struct multi_stop_data msdata;
 
 	preempt_disable();
@@ -262,13 +242,6 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 		.done = &done
 	};
 
-	call_args = (struct irq_cpu_stop_queue_work_info){
-		.cpu1 = cpu1,
-		.cpu2 = cpu2,
-		.work1 = &work1,
-		.work2 = &work2,
-	};
-
 	cpu_stop_init_done(&done, 2);
 	set_state(&msdata, MULTI_STOP_PREPARE);
 
@@ -285,16 +258,11 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 		return -ENOENT;
 	}
 
-	lg_local_lock(&stop_cpus_lock);
-	/*
-	 * Queuing needs to be done by the lowest numbered CPU, to ensure
-	 * that works are always queued in the same order on every CPU.
-	 * This prevents deadlocks.
-	 */
-	smp_call_function_single(min(cpu1, cpu2),
-				 &irq_cpu_stop_queue_work,
-				 &call_args, 1);
-	lg_local_unlock(&stop_cpus_lock);
+	lg_double_lock(&stop_cpus_lock, cpu1, cpu2);
+	cpu_stop_queue_work(cpu1, &work1);
+	cpu_stop_queue_work(cpu2, &work2);
+	lg_double_unlock(&stop_cpus_lock, cpu1, cpu2);
+
 	preempt_enable();
 
 	wait_for_completion(&done.completion);