While splitting flags and pqflags might have been a good idea in theory

to separate locking, on most modern machines this is not enough
since operations on short types touch other short types that share the
same word in memory.

Merge pg_flags and pqflags again and now use atomic operations to change
the flags. Also bump wire_count to an int and pg_version might go
int as well, just for alignment.

tested by many, many. ok miod@

1 files changed, 5 insertions, 7 deletions

diff --git a/sys/uvm/uvm_anon.c b/sys/uvm/uvm_anon.c
index 6da4ac1979e..47a8b81caf1 100644
--- a/sys/uvm/uvm_anon.c
+++ b/sys/uvm/uvm_anon.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_anon.c,v 1.26 2007/04/04 17:44:45 art Exp $	*/
+/*	$OpenBSD: uvm_anon.c,v 1.27 2007/04/13 18:57:49 art Exp $	*/
 /*	$NetBSD: uvm_anon.c,v 1.10 2000/11/25 06:27:59 chs Exp $	*/
 
 /*
@@ -233,7 +233,7 @@ uvm_anfree(anon)
 
 			if ((pg->pg_flags & PG_BUSY) != 0) {
 				/* tell them to dump it when done */
-				pg->pg_flags |= PG_RELEASED;
+				atomic_setbits_int(&pg->pg_flags, PG_RELEASED);
 				UVMHIST_LOG(maphist,
 				    "  anon %p, page %p: BUSY (released!)", 
 				    anon, pg, 0, 0);
@@ -371,9 +371,9 @@ uvm_anon_lockloanpg(anon)
 		 * then we can take over as owner!
 		 */
 
-		if (pg->uobject == NULL && (pg->pqflags & PQ_ANON) == 0) {
+		if (pg->uobject == NULL && (pg->pg_flags & PQ_ANON) == 0) {
 			uvm_lock_pageq();
-			pg->pqflags |= PQ_ANON;		/* take ownership... */
+			atomic_setbits_int(&pg->pg_flags, PQ_ANON);
 			pg->loan_count--;	/* ... and drop our loan */
 			uvm_unlock_pageq();
 		}
@@ -508,16 +508,14 @@ anon_pagein(anon)
 	uobj = pg->uobject;
 	uvm_swap_free(anon->an_swslot, 1);
 	anon->an_swslot = 0;
-	pg->pg_flags &= ~(PG_CLEAN);
+	atomic_clearbits_int(&pg->pg_flags, PG_CLEAN);
 
 	/*
 	 * deactivate the page (to put it on a page queue)
 	 */
 
 	pmap_clear_reference(pg);
-#ifndef UBC
 	pmap_page_protect(pg, VM_PROT_NONE);
-#endif
 	uvm_lock_pageq();
 	uvm_pagedeactivate(pg);
 	uvm_unlock_pageq();