[src/trunk]: src/sys/uvm uvm_fault_internal: Put a goto label "Case1" as well...

[uebayasi <uebayasi%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/afc6eb6fb43c
branches:  trunk
changeset: 751287:afc6eb6fb43c
user:      uebayasi <uebayasi%NetBSD.org@localhost>
date:      Sun Jan 31 07:32:35 2010 +0000

description:
uvm_fault_internal: Put a goto label "Case1" as well as "Case2".  Clarify
that if the faulting page is shadowed, we don't care the lower layer at all.

diffstat:

 sys/uvm/uvm_fault.c |  31 +++++++++++++++----------------
 1 files changed, 15 insertions(+), 16 deletions(-)

diffs (82 lines):

diff -r 2442eaabae27 -r afc6eb6fb43c sys/uvm/uvm_fault.c
--- a/sys/uvm/uvm_fault.c       Sun Jan 31 06:45:09 2010 +0000
+++ b/sys/uvm/uvm_fault.c       Sun Jan 31 07:32:35 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_fault.c,v 1.132 2010/01/31 01:40:12 uebayasi Exp $ */
+/*     $NetBSD: uvm_fault.c,v 1.133 2010/01/31 07:32:35 uebayasi Exp $ */
 
 /*
  *
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.132 2010/01/31 01:40:12 uebayasi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.133 2010/01/31 07:32:35 uebayasi Exp $");
 
 #include "opt_uvmhist.h"
 
@@ -1010,6 +1010,9 @@
         * XXX case.  --thorpej
         */
 
+       if (shadowed == true)
+               goto Case1;
+
        /*
         * if the desired page is not shadowed by the amap and we have a
         * backing object, then we check to see if the backing object would
@@ -1018,7 +1021,7 @@
         * providing a pgo_fault routine.
         */
 
-       if (uobj && shadowed == false && uobj->pgops->pgo_fault != NULL) {
+       if (uobj && uobj->pgops->pgo_fault != NULL) {
                mutex_enter(&uobj->vmobjlock);
                /* locked: maps(read), amap (if there), uobj */
                error = uobj->pgops->pgo_fault(&ufi, startva, pages, npages,
@@ -1042,7 +1045,7 @@
         * (PGO_LOCKED).
         */
 
-       if (uobj && shadowed == false) {
+       if (uobj) {
                mutex_enter(&uobj->vmobjlock);
                /* locked (!shadowed): maps(read), amap (if there), uobj */
                /*
@@ -1145,16 +1148,11 @@
                uobjpage = NULL;
        }
 
-       /* locked (shadowed): maps(read), amap */
-       /* locked (!shadowed): maps(read), amap(if there),
-                uobj(if !null), uobjpage(if !null) */
-       if (shadowed) {
-               KASSERT(mutex_owned(&amap->am_l));
-       } else {
-               KASSERT(amap == NULL || mutex_owned(&amap->am_l));
-               KASSERT(uobj == NULL || mutex_owned(&uobj->vmobjlock));
-               KASSERT(uobjpage == NULL || (uobjpage->flags & PG_BUSY) != 0);
-       }
+       /* locked: maps(read), amap(if there), uobj(if !null), uobjpage(if !null) */
+       KASSERT(!shadowed);
+       KASSERT(amap == NULL || mutex_owned(&amap->am_l));
+       KASSERT(uobj == NULL || mutex_owned(&uobj->vmobjlock));
+       KASSERT(uobjpage == NULL || (uobjpage->flags & PG_BUSY) != 0);
 
        /*
         * note that at this point we are done with any front or back pages.
@@ -1175,10 +1173,11 @@
         * redirect case 2: if we are not shadowed, go to case 2.
         */
 
-       if (shadowed == false)
-               goto Case2;
+       goto Case2;
 
+Case1:
        /* locked: maps(read), amap */
+       KASSERT(mutex_owned(&amap->am_l));
 
        /*
         * handle case 1: fault on an anon in our amap