Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1234918

[RFC][PATCH 03/11] sched: Robustify preemption leak checks

Show all headers | View raw

When we warn about a preempt_count leak; reset the preempt_count to
the known good value such that the problem does not ripple forward.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 kernel/exit.c       |    4 +++-
 kernel/sched/core.c |    4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -706,10 +706,12 @@ void do_exit(long code)
 	smp_mb();
 	raw_spin_unlock_wait(&tsk->pi_lock);
 
-	if (unlikely(in_atomic()))
+	if (unlikely(in_atomic())) {
 		pr_info("note: %s[%d] exited with preempt_count %d\n",
 			current->comm, task_pid_nr(current),
 			preempt_count());
+		preempt_count_set(PREEMPT_ENABLED);
+	}
 
 	/* sync mm's RSS info before statistics gathering */
 	if (tsk->mm)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2960,8 +2960,10 @@ static inline void schedule_debug(struct
 	 * schedule() atomically, we ignore that path. Otherwise whine
 	 * if we are scheduling when we should not.
 	 */
-	if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD))
+	if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD)) {
 		__schedule_bug(prev);
+		preempt_count_set(PREEMPT_DISABLED);
+	}
 	rcu_sleep_check();
 
 	profile_hit(SCHED_PROFILING, __builtin_return_address(0));


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[RFC][PATCH 03/11] sched: Robustify preemption leak checks Peter Zijlstra <peterz@infradead.org> - 2015-09-29 11:50 +0200
  [tip:sched/core] sched/core: Robustify preemption leak checks tip-bot for Peter Zijlstra <tipbot@zytor.com> - 2015-09-29 12:40 +0200
  Re: [RFC][PATCH 03/11] sched: Robustify preemption leak checks Frederic Weisbecker <fweisbec@gmail.com> - 2015-09-29 15:30 +0200
    Re: [RFC][PATCH 03/11] sched: Robustify preemption leak checks Peter Zijlstra <peterz@infradead.org> - 2015-09-29 16:30 +0200
      Re: [RFC][PATCH 03/11] sched: Robustify preemption leak checks Frederic Weisbecker <fweisbec@gmail.com> - 2015-09-29 16:40 +0200
  Re: [RFC][PATCH 03/11] sched: Robustify preemption leak checks Steven Rostedt <rostedt@goodmis.org> - 2015-09-29 17:10 +0200
    Re: [RFC][PATCH 03/11] sched: Robustify preemption leak checks Peter Zijlstra <peterz@infradead.org> - 2015-09-29 17:30 +0200

csiph-web