diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2015-03-23 20:21:51 -0300 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2015-03-23 20:22:48 -0300 |
| commit | 0a4e6be9ca17c54817cf814b4b5aa60478c6df27 (patch) | |
| tree | 461ed6cace26da5c75d1c01982fde2f3ccc5d4fa /kernel/sched | |
| parent | 58d2930f4ee335ab703d768cb0318331fc1bb62c (diff) | |
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+
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f0f831e8a345..d0c4209bb836 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -996,6 +996,13 @@ 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) { @@ -1026,10 +1033,18 @@ 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); |