ck_rwlock: Migrate to acquire / release and other barrier improvements.

include/ck_rwlock.h

@@ -46,7 +46,7 @@ ck_rwlock_init(struct ck_rwlock *rw)
 
 	rw->writer = 0;
 	rw->n_readers = 0;
-	ck_pr_fence_memory();
+	ck_pr_fence_store();
 	return;
 }
 
@@ -54,7 +54,7 @@ CK_CC_INLINE static void
 ck_rwlock_write_unlock(ck_rwlock_t *rw)
 {
 
-	ck_pr_fence_memory();
+	ck_pr_fence_release();
 	ck_pr_store_uint(&rw->writer, 0);
 	return;
 }
@@ -95,7 +95,7 @@ ck_rwlock_write_trylock(ck_rwlock_t *rw)
 	if (ck_pr_fas_uint(&rw->writer, 1) != 0)
 		return false;
 
-	ck_pr_fence_memory();
+	ck_pr_fence_atomic_load();
 
 	if (ck_pr_load_uint(&rw->n_readers) != 0) {
 		ck_rwlock_write_unlock(rw);
@@ -115,7 +115,7 @@ ck_rwlock_write_lock(ck_rwlock_t *rw)
 	while (ck_pr_fas_uint(&rw->writer, 1) != 0)
 		ck_pr_stall();
 
-	ck_pr_fence_memory();
+	ck_pr_fence_atomic_load();
 
 	while (ck_pr_load_uint(&rw->n_readers) != 0)
 		ck_pr_stall();
@@ -140,7 +140,7 @@ ck_rwlock_read_trylock(ck_rwlock_t *rw)
 	 * Serialize with respect to concurrent write
 	 * lock operation.
 	 */
-	ck_pr_fence_memory();
+	ck_pr_fence_atomic_load();
 
 	if (ck_pr_load_uint(&rw->writer) == 0) {
 		ck_pr_fence_load();
@@ -193,7 +193,7 @@ CK_CC_INLINE static void
 ck_rwlock_read_unlock(ck_rwlock_t *rw)
 {
 
-	ck_pr_fence_memory();
+	ck_pr_fence_load_atomic();
 	ck_pr_dec_uint(&rw->n_readers);
 	return;
 }
@@ -225,7 +225,7 @@ ck_rwlock_recursive_write_lock(ck_rwlock_recursive_t *rw, unsigned int tid)
 	while (ck_pr_cas_uint(&rw->rw.writer, 0, tid) == false)
 		ck_pr_stall();
 
-	ck_pr_fence_memory();
+	ck_pr_fence_atomic_load();
 
 	while (ck_pr_load_uint(&rw->rw.n_readers) != 0)
 		ck_pr_stall();
@@ -247,7 +247,7 @@ ck_rwlock_recursive_write_trylock(ck_rwlock_recursive_t *rw, unsigned int tid)
 	if (ck_pr_cas_uint(&rw->rw.writer, 0, tid) == false)
 		return false;
 
-	ck_pr_fence_memory();
+	ck_pr_fence_atomic_load();
 
 	if (ck_pr_load_uint(&rw->rw.n_readers) != 0) {
 		ck_pr_store_uint(&rw->rw.writer, 0);
@@ -264,7 +264,7 @@ ck_rwlock_recursive_write_unlock(ck_rwlock_recursive_t *rw)
 {
 
 	if (--rw->wc == 0) {
-		ck_pr_fence_memory();
+		ck_pr_fence_release();
 		ck_pr_store_uint(&rw->rw.writer, 0);
 	}