Re: /proc/kcore size incorrect ?

[Brian Waite <linwoes@gmail.com>]

On Tuesday 25 October 2005 8:04 am, Matan Peled wrote:
> J.A. Magallon wrote:
> > I expected /proc/kcore to give the size of your installed memory, with
> > the reserved BIOS areas just not accesible, but it looks like it already
> > has them discounted, so gives 1022 Mb.
> >
> > It looks really silly to have a motd say "wellcome to this box, it has
> > 2 xeons and 1022 Mb of RAM".
>
> I don't know why, but 'du' seems to be doing a better job.
>
> chaosite@kaitou ~ $ du /proc/kcore --block-size=1M
> 1024	/proc/kcore
> chaosite@kaitou ~ $ echo $(($(stat -c %s /proc/kcore) / 1024 / 1024))
> 1023
To show just how fragile your tests are, here is what my laptop reports with 1 
GB memory:

bwaite@ronzoni:~> uname -a
Linux ronzoni 2.6.11.4-21.9-default #1 Fri Aug 19 11:58:59 UTC 2005 i686 i686 
i386 GNU/Linux
bwaite@ronzoni:~> du /proc/kcore --block-size=1M
897     /proc/kcore

bwaite@ronzoni:~> echo $(($(stat -c %s /proc/kcore) / 1024 / 1024))
896

bwaite@ronzoni:~> dmesg | grep MEM
127MB HIGHMEM available.
896MB LOWMEM available.

bwaite@ronzoni:~> dmesg | grep Memory:
Memory: 1033684k/1048248k available (1866k kernel code, 13796k reserved, 658k 
data, 204k init, 130744k highmem)

In short why not use free and show what your users can use. Otherwise, just 
make a static motd and change it whenever you change memory configurations. I 
can't believe you are changing that often. If you are going to go overboard 
and write a script just start doing the round up on your own.

Thanks
Brian