sched: Isolate preempt counting in its own config option
Create a new CONFIG_PREEMPT_COUNT that handles the inc/dec
of preempt count offset independently. So that the offset
can be updated by preempt_disable() and preempt_enable()
even without the need for CONFIG_PREEMPT beeing set.
This prepares to make CONFIG_DEBUG_SPINLOCK_SLEEP working
with !CONFIG_PREEMPT where it currently doesn't detect
code that sleeps inside explicit preemption disabled
sections.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 2e681d9..58969b2 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -27,6 +27,21 @@
asmlinkage void preempt_schedule(void);
+#define preempt_check_resched() \
+do { \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ preempt_schedule(); \
+} while (0)
+
+#else /* !CONFIG_PREEMPT */
+
+#define preempt_check_resched() do { } while (0)
+
+#endif /* CONFIG_PREEMPT */
+
+
+#ifdef CONFIG_PREEMPT_COUNT
+
#define preempt_disable() \
do { \
inc_preempt_count(); \
@@ -39,12 +54,6 @@
dec_preempt_count(); \
} while (0)
-#define preempt_check_resched() \
-do { \
- if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
- preempt_schedule(); \
-} while (0)
-
#define preempt_enable() \
do { \
preempt_enable_no_resched(); \
@@ -80,18 +89,17 @@
preempt_check_resched(); \
} while (0)
-#else
+#else /* !CONFIG_PREEMPT_COUNT */
#define preempt_disable() do { } while (0)
#define preempt_enable_no_resched() do { } while (0)
#define preempt_enable() do { } while (0)
-#define preempt_check_resched() do { } while (0)
#define preempt_disable_notrace() do { } while (0)
#define preempt_enable_no_resched_notrace() do { } while (0)
#define preempt_enable_notrace() do { } while (0)
-#endif
+#endif /* CONFIG_PREEMPT_COUNT */
#ifdef CONFIG_PREEMPT_NOTIFIERS