[RFC PATCH v4 14/19] sched/fair: Add a few assertions

From: Vineeth Remanan Pillai
Date: Wed Oct 30 2019 - 14:34:33 EST


From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/sched/fair.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e3b7e8ba1420..840d27628d36 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5984,6 +5984,11 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
struct sched_domain *sd;
int i, recent_used_cpu;

+ /*
+ * per-cpu select_idle_mask usage
+ */
+ lockdep_assert_irqs_disabled();
+
if (available_idle_cpu(target))
return target;

@@ -6439,8 +6444,6 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu)
* certain conditions an idle sibling CPU if the domain has SD_WAKE_AFFINE set.
*
* Returns the target CPU number.
- *
- * preempt must be disabled.
*/
static int
select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_flags)
@@ -6451,6 +6454,11 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
int want_affine = 0;
int sync = (wake_flags & WF_SYNC) && !(current->flags & PF_EXITING);

+ /*
+ * required for stable ->cpus_allowed
+ */
+ lockdep_assert_held(&p->pi_lock);
+
if (sd_flag & SD_BALANCE_WAKE) {
record_wakee(p);

--
2.17.1