Somethings eating my memory...

[Kurt Granroth]

Steven M. Klass wrote:
> Here a simple one (ha, ha, ha).  I reboot my machine, boot into X
> (4.0.3).  I log in and KDE 2.1 shows up.  I pull up Eterm and type
> top.  It's using 
> 
> Initial Logon:
> Mem:   384136K av,   68104K used,  316032K free,       0K shrd,    2268K buff
> Swap:  530104K av,       0K used,  530104K free                   34472Kcached
> 
> 2 hrs later
> Mem:   384136K av,  133620K used,  250516K free,       0K shrd,    4640K buff
> Swap:  530104K av,       0K used,  530104K free                   60572Kcached
> 
> 2 days later
> Mem:   384136K av,  374572K used,    9564K free,       0K shrd,    1396K buff
> Swap:  530104K av,     108K used,  529996K free                138140Kcached
> 
> How do you begin to really track this memory consuption down.  Keep in mind I 
> am using this machine and I need to continue to use this.  Oddly, I never 
> seem to used my swap, even if I'm doing some heavy computing (CAE design 
> drawing) 
> 
> All suggestions welcome.  It looks like something isn't properly releasing 
> the memory...  How can I track this..

Not necessarily.  Memory usage in Linux isn't as simple as most people
think.  This is because the kernel will actually cache things like
most used memory spaces and file listings and the like.  You can
verify the latter yourself by doing this:

% time find / >& /dev/null
% time find / >& /dev/null

The second time is *much* faster because the file listings are cached
in memory.

You can also verify some of this by running a huge memory hog (VMWare,
for instance) and then exiting it.  You'll see that the memory 'used'
has dropped dramatically.

Basically, as long as you're not getting into swap, you should be
fine.  If you *are* getting into swap, then look at the highest memory
using problems and see if they are growing.  To do so in 'top', just
press 'M'
-- 
Kurt Granroth            | http://www.granroth.org
KDE Developer/Evangelist | SuSE Labs Open Source Developer
granroth@kde.org         | granroth@suse.com
            KDE -- Conquer Your Desktop