o Remove the acquisition and release of Giant from the idle priority thread

   that pre-zeroes free pages.
 o Remove GIANT_REQUIRED from some low-level page queue functions.  (Instead
   assertions on the page queue lock are being added to the higher-level
   functions, like vm_page_wire(), etc.)

In collaboration with:	peter

2 files changed, 1 insertions, 8 deletions

diff --git a/sys/vm/vm_pageq.c b/sys/vm/vm_pageq.c
index d6036a8..5a5c0c6 100644
--- a/sys/vm/vm_pageq.c
+++ b/sys/vm/vm_pageq.c
@@ -195,7 +195,6 @@ _vm_pageq_find(int basequeue, int index)
 	vm_page_t m = NULL;
 	struct vpgqueues *pq;
 
-	GIANT_REQUIRED;
 	pq = &vm_page_queues[basequeue];
 
 	/*
@@ -219,8 +218,6 @@ vm_pageq_find(int basequeue, int index, boolean_t prefer_zero)
 {
         vm_page_t m;
 
-	GIANT_REQUIRED;
-
 #if PQ_L2_SIZE > 1
         if (prefer_zero) {
                 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist);
diff --git a/sys/vm/vm_zeroidle.c b/sys/vm/vm_zeroidle.c
index d852b9b..46db4e7 100644
--- a/sys/vm/vm_zeroidle.c
+++ b/sys/vm/vm_zeroidle.c
@@ -74,18 +74,15 @@ vm_page_zero_idle(void)
 	static int free_rover;
 	vm_page_t m;
 
-	mtx_lock(&Giant);
 	mtx_lock_spin(&vm_page_queue_free_mtx);
 	zero_state = 0;
 	m = vm_pageq_find(PQ_FREE, free_rover, FALSE);
 	if (m != NULL && (m->flags & PG_ZERO) == 0) {
 		vm_pageq_remove_nowakeup(m);
 		mtx_unlock_spin(&vm_page_queue_free_mtx);
-		mtx_unlock(&Giant);
 		pmap_zero_page_idle(m);
-		mtx_lock(&Giant);
 		mtx_lock_spin(&vm_page_queue_free_mtx);
-		vm_page_flag_set(m, PG_ZERO);
+		m->flags |= PG_ZERO;
 		vm_pageq_enqueue(PQ_FREE + m->pc, m);
 		++vm_page_zero_count;
 		++cnt_prezero;
@@ -94,7 +91,6 @@ vm_page_zero_idle(void)
 	}
 	free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK;
 	mtx_unlock_spin(&vm_page_queue_free_mtx);
-	mtx_unlock(&Giant);
 	return 1;
 }