[PATCH 01/19] sched/fair: Add a few assertions

From: Peter Zijlstra
Date: Thu Apr 22 2021 - 08:37:01 EST



Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/sched/fair.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6246,6 +6246,11 @@ static int select_idle_sibling(struct ta
task_util = uclamp_task_util(p);
}

+ /*
+ * per-cpu select_idle_mask usage
+ */
+ lockdep_assert_irqs_disabled();
+
if ((available_idle_cpu(target) || sched_idle_cpu(target)) &&
asym_fits_capacity(task_util, target))
return target;
@@ -6711,8 +6716,6 @@ static int find_energy_efficient_cpu(str
* 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 wake_flags)
@@ -6725,6 +6728,10 @@ select_task_rq_fair(struct task_struct *
/* SD_flags and WF_flags share the first nibble */
int sd_flag = wake_flags & 0xF;

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