svn commit: r206884 - user/kmacy/head_page_lock_2/sys/amd64/amd64

[Kip Macy]

Author: kmacy
Date: Tue Apr 20 03:20:20 2010
New Revision: 206884
URL: http://svn.freebsd.org/changeset/base/206884

Log:
  in pmap_protect only call tryrelock if the page is managed and either the accessed or modified bit is set

Modified:
  user/kmacy/head_page_lock_2/sys/amd64/amd64/pmap.c

Modified: user/kmacy/head_page_lock_2/sys/amd64/amd64/pmap.c
==============================================================================
--- user/kmacy/head_page_lock_2/sys/amd64/amd64/pmap.c	Tue Apr 20 03:02:54 2010	(r206883)
+++ user/kmacy/head_page_lock_2/sys/amd64/amd64/pmap.c	Tue Apr 20 03:20:20 2010	(r206884)
@@ -3317,21 +3317,18 @@ retry:
 			obits = pbits = *pte;
 			if ((pbits & PG_V) == 0)
 				continue;
-			if (pbits & PG_MANAGED) {
-				m = NULL;
+			if ((pbits & PG_MANAGED) &&
+			    (pbits & (PG_M | PG_A))) {
 				if (pa_tryrelock(pmap, pbits & PG_FRAME, &pa))
 					goto restart;
+
+				m = PHYS_TO_VM_PAGE(pbits & PG_FRAME);
 				if (pbits & PG_A) {
-					m = PHYS_TO_VM_PAGE(pbits & PG_FRAME);
 					vm_page_flag_set(m, PG_REFERENCED);
 					pbits &= ~PG_A;
 				}
-				if ((pbits & (PG_M | PG_RW)) == (PG_M | PG_RW)) {
-					if (m == NULL)
-						m = PHYS_TO_VM_PAGE(pbits &
-						    PG_FRAME);
+				if ((pbits & (PG_M | PG_RW)) == (PG_M | PG_RW))
 					vm_page_dirty(m);
-				}
 			}
 
 			if ((prot & VM_PROT_WRITE) == 0)