Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm changes from Paolo Bonzini:
 "Remove from guest code the handling of task migration during a pvclock
  read; instead use the correct protocol in KVM.

  This removes the need for task migration notifiers in core scheduler
  code"

[ The scheduler people really hated the migration notifiers, so this was
  kind of required  - Linus ]

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86: pvclock: Really remove the sched notifier for cross-cpu migrations
  kvm: x86: fix kvmclock update protocol

1 files changed, 0 insertions, 15 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f9123a82cbb6..fe22f7510bce 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1016,13 +1016,6 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
                 rq_clock_skip_update(rq, true);
 }
 
-static ATOMIC_NOTIFIER_HEAD(task_migration_notifier);
-
-void register_task_migration_notifier(struct notifier_block *n)
-{
-        atomic_notifier_chain_register(&task_migration_notifier, n);
-}
-
 #ifdef CONFIG_SMP
 void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 {
@@ -1053,18 +1046,10 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
         trace_sched_migrate_task(p, new_cpu);
 
         if (task_cpu(p) != new_cpu) {
-                struct task_migration_notifier tmn;
-
                 if (p->sched_class->migrate_task_rq)
                         p->sched_class->migrate_task_rq(p, new_cpu);
                 p->se.nr_migrations++;
                 perf_sw_event_sched(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 0);
-
-                tmn.task = p;
-                tmn.from_cpu = task_cpu(p);
-                tmn.to_cpu = new_cpu;
-
-                atomic_notifier_call_chain(&task_migration_notifier, 0, &tmn);
         }
 
         __set_task_cpu(p, new_cpu);