Fri Jan 25 17:12:33 2013 UTC ()

Update the DEBUG section at the tail of pmap_clear_modify().

Nothing prevents page modification after the modify bit was
cleared but before the DEBUG section checks pmap_is_modified(),
so remove this check.

For the same reason "modified" and "changed" may differ, so only
check "modified" implies "changed" here.

Ok: Matthew Green <mrg@netbsd.org>


(hannken)

diff -r1.279 -r1.280 src/sys/arch/sparc64/sparc64/pmap.c

--- src/sys/arch/sparc64/sparc64/pmap.c 2013/01/03 09:40:55	1.279
+++ src/sys/arch/sparc64/sparc64/pmap.c 2013/01/25 17:12:33	1.280

 @@ -1,14 +1,14 @@
-/*	$NetBSD: pmap.c,v 1.279 2013/01/03 09:40:55 martin Exp $	*/
+/*	$NetBSD: pmap.c,v 1.280 2013/01/25 17:12:33 hannken Exp $	*/
 /*
+ *
  * Copyright (C) 1996-1999 Eduardo Horvath.
  * All rights reserved.
+ *
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``AS IS'' AND
 @@ -16,27 +16,27 @@
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR  BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.279 2013/01/03 09:40:55 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.280 2013/01/25 17:12:33 hannken Exp $");
 #undef	NO_VCACHE /* Don't forget the locked TLB in dostart */
 #define	HWREF
 #include "opt_ddb.h"
 #include "opt_multiprocessor.h"
 #include "opt_modular.h"
 #include <sys/param.h>
 #include <sys/malloc.h>
 #include <sys/queue.h>
 #include <sys/systm.h>
 #include <sys/msgbuf.h>
 @@ -2567,37 +2567,33 @@ pmap_clear_modify(struct vm_page *pg)
 				tsb_invalidate(va, pmap);
 				tlb_flush_pte(va, pmap);
+			}
 			/* Then clear the mod bit in the pv */
 			if (pv->pv_va & PV_MOD) {
 				changed |= 1;
 				pv->pv_va &= ~PV_MOD;
+			}
+		}
+	}
 	pv_check();
 	mutex_exit(&pmap_lock);
 #ifdef DEBUG
 	if (pmap_is_modified(pg)) {
 		printf("pmap_clear_modify(): %p still modified!\n", pg);
 		Debugger();
 	DPRINTF(PDB_CHANGEPROT|PDB_REF, ("pmap_clear_modify: pg %p %s\n", pg,
 	    (changed ? "was modified" : "was not modified")));
-	if (modified != changed) {
+	if (modified && modified != changed) {
 		printf("pmap_clear_modify: modified %d changed %d\n",
 		       modified, changed);
 		Debugger();
 	} else return (modified);
 #endif
 	return (changed);
+}
 bool
 pmap_clear_reference(struct vm_page *pg)
+{
 	struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
 	pv_entry_t pv;
 	int rv;
 	int changed = 0;
 #ifdef DEBUG
 	int referenced = 0;