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Add in my little patch for 2.4.x to make sysinfo binary compatable (again)

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-Erik
This commit is contained in:
Eric Andersen 2000-06-21 22:06:56 +00:00
parent afa0662860
commit c5c5e3d144
2 changed files with 88 additions and 0 deletions
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77
examples/kernel-patches/2.4.x-revert-sysinfo.patch Normal file
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@ -0,0 +1,77 @@
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;

11
examples/kernel-patches/WillThisGoIntoTheKernel
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@ -1,3 +1,14 @@
I have been asked several times whether the devps patch will go into the
mainline Linux kernel. The following emails from Alan Cox and Linux Torvalds
make it clear that it is not going to happen. This does not mean this patch
had no value -- it does. It just means that those that like it get to apply it
themselves...
-Erik
-------------------------------
From alan@lxorguk.ukuu.org.uk Thu Apr 13 08:07:22 2000
Return-Path: <alan@lxorguk.ukuu.org.uk>
Delivered-To: andersen@dillweed.dsl.xmission.com