[RFC][PATCH 12/11] sched: Add preempt_count invariant check

From: Peter Zijlstra
Date: Tue Sep 29 2015 - 06:33:42 EST



Ingo requested I keep my debug check for the preempt_count invariant.

Requested-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/sched/core.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2503,6 +2503,11 @@ static struct rq *finish_task_switch(str
struct mm_struct *mm = rq->prev_mm;
long prev_state;

+ if (unlikely(WARN_ONCE(preempt_count() != 2,
+ "corrupted preempt_count: %s/%d/0x%x\n",
+ current->comm, current->pid, preempt_count())))
+ preempt_count_set(INIT_PREEMPT_COUNT);
+
rq->prev_mm = NULL;

/*
--
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