[src/trunk]: src/sys/uvm uvm_pagerealloc(): resurrect the insertion case.

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

details:   https://anonhg.NetBSD.org/src/rev/794c14f76a3a
branches:  trunk
changeset: 972924:794c14f76a3a
user:      ad <ad%NetBSD.org@localhost>
date:      Sat Jun 13 19:55:39 2020 +0000

description:
uvm_pagerealloc(): resurrect the insertion case.

diffstat:

 sys/uvm/uvm_extern.h |   4 ++--
 sys/uvm/uvm_page.c   |  31 +++++++++++++++++++++++--------
 2 files changed, 25 insertions(+), 10 deletions(-)

diffs (82 lines):

diff -r e4a470e2fd86 -r 794c14f76a3a sys/uvm/uvm_extern.h
--- a/sys/uvm/uvm_extern.h      Sat Jun 13 19:47:10 2020 +0000
+++ b/sys/uvm/uvm_extern.h      Sat Jun 13 19:55:39 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_extern.h,v 1.228 2020/06/11 19:20:47 ad Exp $      */
+/*     $NetBSD: uvm_extern.h,v 1.229 2020/06/13 19:55:58 ad Exp $      */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -789,7 +789,7 @@
                                UVM_PGA_STRAT_NORMAL, 0)
 void                   uvm_pagereplace(struct vm_page *,
                            struct vm_page *);
-void                   uvm_pagerealloc(struct vm_page *,
+int                    uvm_pagerealloc(struct vm_page *,
                            struct uvm_object *, voff_t);
 void                   uvm_setpagesize(void);
 
diff -r e4a470e2fd86 -r 794c14f76a3a sys/uvm/uvm_page.c
--- a/sys/uvm/uvm_page.c        Sat Jun 13 19:47:10 2020 +0000
+++ b/sys/uvm/uvm_page.c        Sat Jun 13 19:55:39 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_page.c,v 1.240 2020/06/11 22:21:05 ad Exp $        */
+/*     $NetBSD: uvm_page.c,v 1.241 2020/06/13 19:55:39 ad Exp $        */
 
 /*-
  * Copyright (c) 2019, 2020 The NetBSD Foundation, Inc.
@@ -95,7 +95,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.240 2020/06/11 22:21:05 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.241 2020/06/13 19:55:39 ad Exp $");
 
 #include "opt_ddb.h"
 #include "opt_uvm.h"
@@ -1411,12 +1411,13 @@
  * uvm_pagerealloc: reallocate a page from one object to another
  *
  * => both objects must be locked
- * => both interlocks must be held
  */
 
-void
+int
 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff)
 {
+       int error = 0;
+
        /*
         * remove it from the old object
         */
@@ -1431,11 +1432,25 @@
         */
 
        if (newobj) {
-               /*
-                * XXX we have no in-tree users of this functionality
-                */
-               panic("uvm_pagerealloc: no impl");
+               mutex_enter(&pg->interlock);
+               pg->uobject = newobj;
+               pg->offset = newoff;
+               if (UVM_OBJ_IS_VNODE(newobj)) {
+                       pg->flags |= PG_FILE;
+               } else if (UVM_OBJ_IS_AOBJ(newobj)) {
+                       pg->flags |= PG_AOBJ;
+               }
+               uvm_pageinsert_object(newobj, pg);
+               mutex_exit(&pg->interlock);
+               error = uvm_pageinsert_tree(newobj, pg);
+               if (error != 0) {
+                       mutex_enter(&pg->interlock);
+                       uvm_pageremove_object(newobj, pg);
+                       mutex_exit(&pg->interlock);
+               }
        }
+
+       return error;
 }
 
 #ifdef DEBUG