sched.h: Move (spin|rwlock)_needbreak() to spinlock.h

This lets us kill the dependency on spinlock.h.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 31 insertions, 0 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 31d3d747a9db..0c71f06454d9 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -449,6 +449,37 @@ static __always_inline int spin_is_contended(spinlock_t *lock)
 	return raw_spin_is_contended(&lock->rlock);
 }
 
+/*
+ * Does a critical section need to be broken due to another
+ * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
+ * but a general need for low latency)
+ */
+static inline int spin_needbreak(spinlock_t *lock)
+{
+#ifdef CONFIG_PREEMPTION
+	return spin_is_contended(lock);
+#else
+	return 0;
+#endif
+}
+
+/*
+ * Check if a rwlock is contended.
+ * Returns non-zero if there is another task waiting on the rwlock.
+ * Returns zero if the lock is not contended or the system / underlying
+ * rwlock implementation does not support contention detection.
+ * Technically does not depend on CONFIG_PREEMPTION, but a general need
+ * for low latency.
+ */
+static inline int rwlock_needbreak(rwlock_t *lock)
+{
+#ifdef CONFIG_PREEMPTION
+	return rwlock_is_contended(lock);
+#else
+	return 0;
+#endif
+}
+
 #define assert_spin_locked(lock)	assert_raw_spin_locked(&(lock)->rlock)
 
 #else  /* !CONFIG_PREEMPT_RT */