Re: Emacs bzr memory footprint

[Dan Nicolaescu]

Carsten Mattner <address@hidden> writes:

> I've been wondering whether it's normal for Emacs to start with
> 10 or 20 megs and stay at ~100 megs after opening and closing
> multiple buffers.
>
> I do use ido and a couple other common modes/libs for various
> features or programming languages. Nothing fancy, really.
> I can try to test with no custom config, but won't be able to use
> it for real work, just letting it idle.
>
> Is this in the normal footprint or way out of place when
> Emacs sits there idling with not a single buffer open.
>
> Emacs versions in use are Linux with X but no toolkit and
> Cocoa Emacs, both from bzr.
>
> Does Emacs have some kind of memory reclaim or gc mechanism?

Memory can only be return back to the system in chunks (pages usually)
and only when the complete chunk becomes free. Because how the
allocation works it is possible to have on the same chunk data that is
free (like a buffer that has been killed) and data that is not: history,
lisp functions and data, so it is never completely free. 

As a data point we are not doing too bad, this emacs from work:

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND            
     
19053 dann      16   0  133m 129m 3864 S  0.0  1.6 177:42.07 emacs              
      

has been running for 212 days, 3 hours, 45 minutes, 2 seconds

it has 202 open buffers, the terminal frame count has reached 678 
and the memory usage is still reasonable after that much time of daily
usage .