move allocations between half a page and a page as close to the end of

the page as possible (i.e. make malloc option P a default).
ok art@ millert@ krw@

2 files changed, 5 insertions, 4 deletions

diff --git a/src/lib/libc/stdlib/malloc.3 b/src/lib/libc/stdlib/malloc.3
index a6a8014433..79d36d61fd 100644
--- a/src/lib/libc/stdlib/malloc.3
+++ b/src/lib/libc/stdlib/malloc.3
@@ -30,9 +30,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     $OpenBSD: malloc.3,v 1.56 2008/11/02 14:42:01 otto Exp $
+.\"     $OpenBSD: malloc.3,v 1.57 2008/11/20 09:05:15 otto Exp $
 .\"
-.Dd $Mdocdate: November 2 2008 $
+.Dd $Mdocdate: November 20 2008 $
 .Dt MALLOC 3
 .Os
 .Sh NAME
@@ -254,6 +254,7 @@ Freed chunks are filled with 0xdf.
 Allocations larger than half a page but smaller that a page
 are aligned to the end of a page to catch buffer overruns in more
 cases.
+This is the default.
 .It Cm R
 .Dq realloc .
 Always reallocate when
diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index 4e33d33b1b..0f1f088b44 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: malloc.c,v 1.109 2008/11/20 09:01:24 otto Exp $       */
+/*      $OpenBSD: malloc.c,v 1.110 2008/11/20 09:05:15 otto Exp $       */
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -154,7 +154,7 @@ static int	malloc_active;		/* status of malloc */
 static int      malloc_freeprot;        /* mprotect free pages PROT_NONE? */
 static int      malloc_hint;            /* call madvice on free pages?  */
 static int      malloc_junk;            /* junk fill? */
-static int      malloc_move;            /* move allocations to end of page? */
+static int      malloc_move = 1;        /* move allocations to end of page? */
 static int      malloc_realloc;         /* always realloc? */
 static int      malloc_xmalloc;         /* xmalloc behaviour? */
 static int      malloc_zero;            /* zero fill? */