sched/core: Avoid _cond_resched() for PREEMPT=y
On fully preemptible kernels _cond_resched() is pointless, so avoid
emitting any code for it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f00ee8e..b99fcd1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -3209,7 +3209,11 @@
* cond_resched_lock() will drop the spinlock before scheduling,
* cond_resched_softirq() will enable bhs before scheduling.
*/
+#ifndef CONFIG_PREEMPT
extern int _cond_resched(void);
+#else
+static inline int _cond_resched(void) { return 0; }
+#endif
#define cond_resched() ({ \
___might_sleep(__FILE__, __LINE__, 0); \
