Reduce the scope of the page queues lock and the number of

PG_REFERENCED changes in vm_pageout_object_deactivate_pages().
Simplify this function's inner loop using TAILQ_FOREACH(), and shorten
some of its overly long lines.  Update a stale comment.

Assert that PG_REFERENCED may be cleared only if the object containing
the page is locked.  Add a comment documenting this.

Assert that a caller to vm_page_requeue() holds the page queues lock,
and assert that the page is on a page queue.

Push down the page queues lock into pmap_ts_referenced() and
pmap_page_exists_quick().  (As of now, there are no longer any pmap
functions that expect to be called with the page queues lock held.)

Neither pmap_ts_referenced() nor pmap_page_exists_quick() should ever
be passed an unmanaged page.  Assert this rather than returning "0"
and "FALSE" respectively.

ARM:

Simplify pmap_page_exists_quick() by switching to TAILQ_FOREACH().

Push down the page queues lock inside of pmap_clearbit(), simplifying
pmap_clear_modify(), pmap_clear_reference(), and pmap_remove_write().
Additionally, this allows for avoiding the acquisition of the page
queues lock in some cases.

PowerPC/AIM:

moea*_page_exits_quick() and moea*_page_wired_mappings() will never be
called before pmap initialization is complete.  Therefore, the check
for moea_initialized can be eliminated.

Push down the page queues lock inside of moea*_clear_bit(),
simplifying moea*_clear_modify() and moea*_clear_reference().

The last parameter to moea*_clear_bit() is never used.  Eliminate it.

PowerPC/BookE:

Simplify mmu_booke_page_exists_quick()'s control flow.

Reviewed by:	kib@

1 files changed, 14 insertions, 14 deletions

diff --git a/sys/ia64/ia64/pmap.c b/sys/ia64/ia64/pmap.c
index 373d019..56e8a42 100644
--- a/sys/ia64/ia64/pmap.c
+++ b/sys/ia64/ia64/pmap.c
@@ -1837,23 +1837,23 @@ pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
 {
 	pv_entry_t pv;
 	int loops = 0;
+	boolean_t rv;
 
-	if (m->flags & PG_FICTITIOUS)
-		return FALSE;
-
-	/*
-	 * Not found, check current mappings returning immediately if found.
-	 */
-	mtx_assert(&vm_page_queue_mtx, MA_OWNED);
+	KASSERT((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0,
+	    ("pmap_page_exists_quick: page %p is not managed", m));
+	rv = FALSE;
+	vm_page_lock_queues();
 	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
 		if (pv->pv_pmap == pmap) {
-			return TRUE;
+			rv = TRUE;
+			break;
 		}
 		loops++;
 		if (loops >= 16)
 			break;
 	}
-	return (FALSE);
+	vm_page_unlock_queues();
+	return (rv);
 }
 
 /*
@@ -1949,9 +1949,9 @@ pmap_ts_referenced(vm_page_t m)
 	pv_entry_t pv;
 	int count = 0;
 
-	if (m->flags & PG_FICTITIOUS)
-		return 0;
-
+	KASSERT((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0,
+	    ("pmap_ts_referenced: page %p is not managed", m));
+	vm_page_lock_queues();
 	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
 		PMAP_LOCK(pv->pv_pmap);
 		oldpmap = pmap_switch(pv->pv_pmap);
@@ -1965,8 +1965,8 @@ pmap_ts_referenced(vm_page_t m)
 		pmap_switch(oldpmap);
 		PMAP_UNLOCK(pv->pv_pmap);
 	}
-
-	return count;
+	vm_page_unlock_queues();
+	return (count);
 }
 
 /*