Linux memory leak?

Joshua Baker-LePain jlb17 at
Thu Feb 28 12:42:09 PST 2002

On Thu, 28 Feb 2002 at 2:58pm, Josip Loncaric wrote

> # free
>              total       used       free     shared    buffers    
> cached
> Mem:        512444     449196      63248          0      70164     
> 76332
> -/+ buffers/cache:     302700     209744
> Swap:      1060272     285492     774780
> If I add up all RSS numbers reported by 'ps -e v' I get only about
> 20,500 KB, and yet this dual CPU system reports 302,700 KB RAM used
> (without even counting buffers or cache).  Apparently, only 'reboot' can
> recover the missing 282,200 KB.  Any ideas on tracking down where the
> missing memory went?

I've seen this behavior even after very little uptime.  All you have to do 
is have a process swap heavily.  When that process goes away, it seems as 
if what's left in swap also stays in memory.  Further memory pressure 
makes stuff then get paged *out* of swap.

I tracked it down to an existing bugzilla report:

There doesn't seem to be an official resolution from RedHat yet.  But a 
custom compiled 2.4.17 didn't show this behavior.

Joshua Baker-LePain
Department of Biomedical Engineering
Duke University

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