x86: kvm: Revert "remove sched notifier for cross-cpu migrations"

The following point:

    2. per-CPU pvclock time info is updated if the
       underlying CPU changes.

Is not true anymore since "KVM: x86: update pvclock area conditionally,
on cpu migration".

Add task migration notification back.

Problem noticed by Andy Lutomirski.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
CC: stable@kernel.org # 3.11+
This commit is contained in:
Marcelo Tosatti
2015-03-23 20:21:51 -03:00
parent 58d2930f4e
commit 0a4e6be9ca
5 changed files with 76 additions and 8 deletions

View File

@@ -176,6 +176,14 @@ extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
extern void calc_global_load(unsigned long ticks);
extern void update_cpu_load_nohz(void);
/* Notifier for when a task gets migrated to a new CPU */
struct task_migration_notifier {
struct task_struct *task;
int from_cpu;
int to_cpu;
};
extern void register_task_migration_notifier(struct notifier_block *n);
extern unsigned long get_parent_ip(unsigned long addr);
extern void dump_cpu_task(int cpu);