I have a version of free I wrote for BusyBox that uses sysinfo (rather then
/proc) to get its information.  Under 2.2.x it reports normal stuff, i.e.
    [andersen@dillweed busybox]$ ./free
                  total         used         free       shared      buffers
      Mem:       127800       124268         3532        16956         7544
     Swap:       128516        13584       114932
    Total:       256316       137852       118464

while under 2.2.0-test1-ac7 it reports wierd numbers (~ #/4096)
    [andersen@dillweed busybox]$ ./free
                  total         used         free       shared      buffers
      Mem:           30           11           19            0            1
     Swap:           31            0           31
    Total:           61           11           50

After investigating the problem, it turns out that somewhere during 2.3.x the
values for memory stored in struct sysinfo changed from being stored as bytes
to being units of PAGE_SIZE, but kernel/info.c was never updated to reflect
this change in definition.

Breaking free isn't that big of a deal, but I also use sysinfo in init to check
that the box has enough ram from within the init process (and no, mounting
/proc from within init and reading /proc/meminfo is not a good solution.
BusyBox is often used in embedded systems where /proc is not compiled in).

The following patch reinstates the traditional sysinfo(2) interface by
returning bytes (not units of PAGE_SIZE) for memory values.

An additional patch suggestion (not included here) would be to eliminate the
supurfluous "mem_unit" variable from struct_sysinfo in include/linux/kernel.h
and arch/*/mm/init.c.

 -Erik

--
Erik B. Andersen   Web:    http://www.xmission.com/~andersen/
                   email:  andersee@debian.org
--This message was written using 73% post-consumer electrons--

--- linux/kernel/info.c.orig    Mon Aug 23 12:15:53 1999
+++ linux/kernel/info.c Sun Jun  4 01:13:11 2000
@@ -2,6 +2,8 @@
  * linux/kernel/info.c
  *
  * Copyright (C) 1992 Darren Senn
+ * Fixed to once again return bytes instead of page counts,
+ * June 2000, by Erik Andersen <andersee@debian.org>
  */

 /* This implements the sysinfo() system call */
@@ -10,7 +12,6 @@
 #include <linux/unistd.h>
 #include <linux/swap.h>
 #include <linux/smp_lock.h>
-
 #include <asm/uaccess.h>

 asmlinkage long sys_sysinfo(struct sysinfo *info)
@@ -31,6 +32,17 @@

        si_meminfo(&val);
        si_swapinfo(&val);
+
+       /* These are in units of PAGE_SIZE, but this interface
+        * has always returned bytes.  Make it return bytes */
+       val.totalram*=PAGE_SIZE;
+       val.freeram*=PAGE_SIZE;
+       val.sharedram*=PAGE_SIZE;
+       val.bufferram*=PAGE_SIZE;
+       val.totalswap*=PAGE_SIZE;
+       val.freeswap*=PAGE_SIZE;
+       val.totalhigh*=PAGE_SIZE;
+       val.freehigh*=PAGE_SIZE;

        if (copy_to_user(info, &val, sizeof(struct sysinfo)))
                return -EFAULT;