[src/trunk]: src/lib/libc/stdlib Compute page size related parameters at run-...

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

details:   https://anonhg.NetBSD.org/src/rev/89c559242ce4
branches:  trunk
changeset: 474411:89c559242ce4
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Mon Jul 05 21:49:05 1999 +0000

description:
Compute page size related parameters at run-time.

diffstat:

 lib/libc/stdlib/malloc.c |  42 +++++++++++++++++-------------------------
 1 files changed, 17 insertions(+), 25 deletions(-)

diffs (107 lines):

diff -r 026eedb7abf5 -r 89c559242ce4 lib/libc/stdlib/malloc.c
--- a/lib/libc/stdlib/malloc.c  Mon Jul 05 21:38:21 1999 +0000
+++ b/lib/libc/stdlib/malloc.c  Mon Jul 05 21:49:05 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: malloc.c,v 1.19 1999/07/05 21:08:38 thorpej Exp $      */
+/*     $NetBSD: malloc.c,v 1.20 1999/07/05 21:49:05 thorpej Exp $      */
 
 /*
  * ----------------------------------------------------------------------------
@@ -32,10 +32,6 @@
 /*
  * The basic parameters you can tweak.
  *
- * malloc_pageshift    pagesize = 1 << malloc_pageshift
- *                     It's probably best if this is the native
- *                     page size, but it doesn't have to be.
- *
  * malloc_minsize      minimum size of an allocation in bytes.
  *                     If this is too small it's too much work
  *                     to manage them.  This is also the smallest
@@ -46,11 +42,9 @@
 
 #if defined(__FreeBSD__)
 #   if defined(__i386__)
-#       define malloc_pageshift                12U
 #       define malloc_minsize          16U
 #   endif
 #   if defined(__alpha__)
-#       define malloc_pageshift                13U
 #       define malloc_minsize          16U
 #   endif
 #   if !defined(__NETBSD_SYSCALLS)
@@ -68,13 +62,10 @@
 #endif /* __FreeBSD__ */
 
 #if defined(__NetBSD__)
-#   include <sys/param.h>
-#   define malloc_pageshift             PGSHIFT
 #   define malloc_minsize               16U
 #endif /* __NetBSD__ */
 
 #if defined(__sparc__) && defined(sun)
-#   define malloc_pageshift            12U
 #   define malloc_minsize              16U
 #   define MAP_ANON                    (0)
     static int fdzero;
@@ -86,7 +77,6 @@
 
 /* Insert your combination here... */
 #if defined(__FOOCPU__) && defined(__BAROS__)
-#   define malloc_pageshift            12U
 #   define malloc_minsize              16U
 #endif /* __FOOCPU__ && __BAROS__ */
 
@@ -145,29 +135,21 @@
 #define MALLOC_FOLLOW  ((struct pginfo*) 3)
 #define MALLOC_MAGIC   ((struct pginfo*) 4)
 
-#ifndef malloc_pageshift
-#define malloc_pageshift               12U
-#endif
+/*
+ * Page size related parameters, computed at run-time.
+ */
+static size_t malloc_pagesize;
+static size_t malloc_pageshift;
+static size_t malloc_pagemask;
 
 #ifndef malloc_minsize
 #define malloc_minsize                 16U
 #endif
 
-#if !defined(malloc_pagesize)
-#define malloc_pagesize                        (1UL<<malloc_pageshift)
-#endif
-
-#if ((1<<malloc_pageshift) != malloc_pagesize)
-#error "(1<<malloc_pageshift) != malloc_pagesize"
-#endif
-
 #ifndef malloc_maxsize
 #define malloc_maxsize                 ((malloc_pagesize)>>1)
 #endif
 
-/* A mask for the offset inside a page.  */
-#define malloc_pagemask        ((malloc_pagesize)-1)
-
 #define pageround(foo) (((foo) + (malloc_pagemask))&(~(malloc_pagemask)))
 #define ptr2index(foo) (((u_long)(foo) >> malloc_pageshift)-malloc_origo)
 
@@ -397,6 +379,16 @@
     int i, j;
     int errnosave;
 
+    /*
+     * Compute page-size related variables.
+     */
+    malloc_pagesize = sysconf(_SC_PAGESIZE);
+    malloc_pagemask = malloc_pagesize - 1;
+    for (malloc_pageshift = 0;
+        (1UL << malloc_pageshift) != malloc_pagesize;
+        malloc_pageshift++)
+       /* nothing */ ;
+
     INIT_MMAP();
 
 #ifdef MALLOC_EXTRA_SANITY