Remove the volatile qualifier from busy_lock.

Use atomic(9) to load the lock state.  Some places were doing this
already, so it was inconsistent.  In initialization code, the lock state
is still initialized with plain stores.

Reviewed by:	alc, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D25861

1 files changed, 9 insertions, 9 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 8c2df3e78e17..ce107645d6a6 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -908,7 +908,7 @@ vm_page_busy_downgrade(vm_page_t m)
 
 	vm_page_assert_xbusied(m);
 
-	x = m->busy_lock;
+	x = vm_page_busy_fetch(m);
 	for (;;) {
 		if (atomic_fcmpset_rel_int(&m->busy_lock,
 		    &x, VPB_SHARERS_WORD(1)))
@@ -931,7 +931,7 @@ vm_page_busy_tryupgrade(vm_page_t m)
 
 	vm_page_assert_sbusied(m);
 
-	x = m->busy_lock;
+	x = vm_page_busy_fetch(m);
 	ce = VPB_CURTHREAD_EXCLUSIVE;
 	for (;;) {
 		if (VPB_SHARERS(x) > 1)
@@ -955,7 +955,7 @@ vm_page_sbusied(vm_page_t m)
 {
 	u_int x;
 
-	x = m->busy_lock;
+	x = vm_page_busy_fetch(m);
 	return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
 }
 
@@ -971,7 +971,7 @@ vm_page_sunbusy(vm_page_t m)
 
 	vm_page_assert_sbusied(m);
 
-	x = m->busy_lock;
+	x = vm_page_busy_fetch(m);
 	for (;;) {
 		KASSERT(x != VPB_FREED,
 		    ("vm_page_sunbusy: Unlocking freed page."));
@@ -1072,7 +1072,7 @@ _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex,
 
 	xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0;
 	sleepq_lock(m);
-	x = atomic_load_int(&m->busy_lock);
+	x = vm_page_busy_fetch(m);
 	do {
 		/*
 		 * If the page changes objects or becomes unlocked we can
@@ -1110,7 +1110,7 @@ vm_page_trysbusy(vm_page_t m)
 	u_int x;
 
 	obj = m->object;
-	x = m->busy_lock;
+	x = vm_page_busy_fetch(m);
 	for (;;) {
 		if ((x & VPB_BIT_SHARED) == 0)
 			return (0);
@@ -1146,7 +1146,7 @@ vm_page_tryxbusy(vm_page_t m)
 {
 	vm_object_t obj;
 
-        if (atomic_cmpset_acq_int(&(m)->busy_lock, VPB_UNBUSIED,
+        if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED,
             VPB_CURTHREAD_EXCLUSIVE) == 0)
 		return (0);
 
@@ -1354,7 +1354,7 @@ vm_page_readahead_finish(vm_page_t m)
 	 * have shown that deactivating the page is usually the best choice,
 	 * unless the page is wanted by another thread.
 	 */
-	if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
+	if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0)
 		vm_page_activate(m);
 	else
 		vm_page_deactivate(m);
@@ -1719,7 +1719,7 @@ vm_page_busy_release(vm_page_t m)
 {
 	u_int x;
 
-	x = atomic_load_int(&m->busy_lock);
+	x = vm_page_busy_fetch(m);
 	for (;;) {
 		if (x == VPB_FREED)
 			break;