[src/netbsd-1-6]: src/sys/uvm Pull up revision 1.78 (requested by thorpej in ...

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

details:   https://anonhg.NetBSD.org/src/rev/f9c7ddac7e32
branches:  netbsd-1-6
changeset: 529570:f9c7ddac7e32
user:      he <he%NetBSD.org@localhost>
date:      Sat Nov 30 14:09:06 2002 +0000

description:
Pull up revision 1.78 (requested by thorpej in ticket #759):
  When breaking a loan due to a page fault, check to see if
  the other kind of reference-holder (anon or object) is
  referencing the page.  If not, the page must be removed
  from the paging queue.

diffstat:

 sys/uvm/uvm_fault.c |  28 +++++++++++++++++++++++-----
 1 files changed, 23 insertions(+), 5 deletions(-)

diffs (59 lines):

diff -r 58a9371da817 -r f9c7ddac7e32 sys/uvm/uvm_fault.c
--- a/sys/uvm/uvm_fault.c       Sat Nov 30 14:07:13 2002 +0000
+++ b/sys/uvm/uvm_fault.c       Sat Nov 30 14:09:06 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_fault.c,v 1.76.4.1 2002/11/30 14:07:13 he Exp $    */
+/*     $NetBSD: uvm_fault.c,v 1.76.4.2 2002/11/30 14:09:06 he Exp $    */
 
 /*
  *
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.76.4.1 2002/11/30 14:07:13 he Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.76.4.2 2002/11/30 14:09:06 he Exp $");
 
 #include "opt_uvmhist.h"
 
@@ -1091,12 +1091,22 @@
                                pmap_page_protect(anon->u.an_page,
                                                  VM_PROT_NONE);
                                uvm_lock_pageq();         /* KILL loan */
-                               if (uobj)
-                                       /* if we were loaning */
-                                       anon->u.an_page->loan_count--;
+
                                anon->u.an_page->uanon = NULL;
                                /* in case we owned */
                                anon->u.an_page->pqflags &= ~PQ_ANON;
+
+                               if (uobj) {
+                                       /* if we were receiver of loan */
+                                       anon->u.an_page->loan_count--;
+                               } else {
+                                       /*
+                                        * we were the lender (A->K); need
+                                        * to remove the page from pageq's.
+                                        */
+                                       uvm_pagedequeue(anon->u.an_page);
+                               }
+
                                uvm_pageactivate(pg);
                                uvm_unlock_pageq();
                                if (uobj) {
@@ -1486,6 +1496,14 @@
                                uvm_pagerealloc(uobjpage, NULL, 0);
 
                                /*
+                                * if the page is no longer referenced by
+                                * an anon (i.e. we are breaking an O->K
+                                * loan), then remove it from any pageq's.
+                                */
+                               if (uobjpage->uanon == NULL)
+                                       uvm_pagedequeue(uobjpage);
+
+                               /*
                                 * at this point we have absolutely no
                                 * control over uobjpage
                                 */