Memory usage: jemalloc v/s libc allocator

[Jason Evans]

It appears that you're measuring all privately mapped virtual memory, but what you really want to measure is physical memory usage.  jemalloc typically maps at least two 4 MiB chunks of virtual memory early during startup, but most of that memory is initially untouched, and therefore not a significant resource utilization issue.  Look at "resident" memory usage (RSS column reported by the top utility) instead of virtual memory usage.

Thanks,
Jason

> On Mar 3, 2015, at 9:21 AM, Eduardo Silva <edsiper at gmail.com> wrote:
> 
> Initially I used gnome-system-monitor, then I did it with ps_mem.py
> script which can be found here:
> 
>         https://raw.githubusercontent.com/pixelb/ps_mem/master/ps_mem.py
> 
> the results are:
> 
> 1) System malloc:
> 
> $ python ps_mem.py -p 22545
>   Private  +   Shared  =  RAM used    Program
> 
>   2.5 MiB +  41.0 KiB =   2.5 MiB    monkey
>   ---------------------------------
>                                  2.5 MiB
> 
> 2) with Jemalloc:
> 
> $ python ps_mem.py -p 26105
>   Private  +   Shared  =  RAM used    Program
> 
>   14.6 MiB +  42.5 KiB =  14.6 MiB    monkey
>   ---------------------------------
>                                14.6 MiB
> 
> note: the server is not receiving any request.
> 
> thanks
> 
> 
> On Tue, Mar 3, 2015 at 10:49 AM, Daniel Micay <danielmicay at gmail.com> wrote:
>> On 03/03/15 09:38 AM, Eduardo Silva wrote:
>>> Hi,
>>> 
>>> I got some reports about high memory usage by our open source project
>>> when jemalloc is enabled, to put you in context: Monkey HTTP Server[0]
>>> by default uses jemalloc in static linking mode, but optionally at
>>> build time can use the common system allocator.
>>> 
>>> When starting the server with jemalloc, the server uses an average of
>>> 8MB, when is disabled (common system allocator) it goes down to 174KB.
>>> This is a major concern when used on Embedded environments so I would
>>> like to know how can we reduce the space used by jemalloc initially.
>>> 
>>> If required I can provide steps to reproduce the scenario.
>>> 
>>> [0] http://monkey-project.com
>>> 
>>> thanks for your time,
>> 
>> How are you measuring memory usage?
>> 
>> 
>> _______________________________________________
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>> jemalloc-discuss at canonware.com
>> http://www.canonware.com/mailman/listinfo/jemalloc-discuss
>> 
> 
> 
> 
> -- 
> Eduardo Silva
> http://edsiper.linuxchile.cl
> http://monkey-project.com
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>