[src/trunk]: src/sys/uvm Fix the corruption of ps->start_hint.

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

details:   https://anonhg.NetBSD.org/src/rev/9800685ff520
branches:  trunk
changeset: 761248:9800685ff520
user:      matt <matt%NetBSD.org@localhost>
date:      Sat Jan 22 01:36:27 2011 +0000

description:
Fix the corruption of ps->start_hint.

diffstat:

 sys/uvm/uvm_pglist.c |  18 ++++++++++++++----
 1 files changed, 14 insertions(+), 4 deletions(-)

diffs (46 lines):

diff -r 7c54d3e1bf18 -r 9800685ff520 sys/uvm/uvm_pglist.c
--- a/sys/uvm/uvm_pglist.c      Sat Jan 22 00:32:41 2011 +0000
+++ b/sys/uvm/uvm_pglist.c      Sat Jan 22 01:36:27 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_pglist.c,v 1.54 2011/01/21 19:27:09 matt Exp $     */
+/*     $NetBSD: uvm_pglist.c,v 1.55 2011/01/22 01:36:27 matt Exp $     */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_pglist.c,v 1.54 2011/01/21 19:27:09 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_pglist.c,v 1.55 2011/01/22 01:36:27 matt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -284,7 +284,12 @@
         * the next time we need to search this segment, start after this
         * chunk of pages we just allocated.
         */
-       ps->start_hint = tryidx + num;
+       ps->start_hint = try + num - ps->avail_start;
+       KASSERTMSG(ps->start_hint <= ps->avail_end - ps->avail_start,
+           ("%x %u (%#x) <= %#"PRIxPADDR" - %#"PRIxPADDR" (%#"PRIxPADDR")",
+           try + num,
+           ps->start_hint, ps->start_hint, ps->avail_end, ps->avail_start,
+           ps->avail_end - ps->avail_start));
 
 #ifdef PGALLOC_VERBOSE
        printf("got %d pgs\n", num);
@@ -410,7 +415,12 @@
         * The next time we need to search this segment,
         * start just after the pages we just allocated.
         */
-       ps->start_hint = try + 1 - ps->start;
+       ps->start_hint = try + 1 - ps->avail_start;
+       KASSERTMSG(ps->start_hint <= ps->avail_end - ps->avail_start,
+           ("%#x %u (%#x) <= %#"PRIxPADDR" - %#"PRIxPADDR" (%#"PRIxPADDR")",
+           try + 1,
+           ps->start_hint, ps->start_hint, ps->avail_end, ps->avail_start,
+           ps->avail_end - ps->avail_start));
 
 #ifdef PGALLOC_VERBOSE
        printf("got %d pgs\n", num - todo);