[Freeciv-Dev] (PR#6925) Measure memory management overhead

["Vasco Alexandre da Silva Costa" <vasc@xxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=6925 >

> [i-freeciv-lists@xxxxxxxxxxxxx - Sat Nov 22 22:50:04 2003]:
> 
> 
> The issue of memory handling overhead comes up quite often. The last
> time in the safe-genlist thread. It is time to fill the discussion
> with some facts. From the profile of an autogame on a Linux system it
> we know that the overhead is quite small. The question is what
> overhead other systems have. Since not all systems support profiling
> the following patch was made.
> 
> The overhead depends on the malloc implmentation (is in the libc) and
> to a lesser extends on the OS.  If you have a non-glibc system please
> apply the patch and run the autogame. The most interresting systems
> here are Win32 and commerical unix versions with their native libc
> version.
> 
> The absolute numbers are not important. Also the autogame isn't
> important (the attached just works).
> 
> You get an output like this:
> 
> [0 malloc    ] calls= 5784117 time=4.518493s 
> [1 realloc   ] calls=  104447 time=0.251182s 
> [2 strdup    ] calls=    4890 time=0.003150s 
> [3 free      ] calls= 5708727 time=3.779969s 
> [4 null      ] calls=11602181 time=4.518997s 
> [5 total     ] calls=       1 time=762.919344s 
> (8.552794-4.518997)/762.919344 = 0.528732%
> 
> Please mail this and your libc and OS version. I for example have used
> glibc-2.2 and linux-2.4.

Freaky. I didn't get the same number of calls:

[0 malloc    ] calls= 5784119 time=3.958480s
[1 realloc   ] calls=  104447 time=0.223444s
[2 strdup    ] calls=    4891 time=0.001654s
[3 free      ] calls= 5708729 time=3.251998s
[4 null      ] calls=11602186 time=4.310892s
[5 total     ] calls=       1 time=595.190819s
(7.435576-4.310892)/595.190819 = 0.524989%

I ran it like this:
./ser -r mem.rc
start

Using current CVS HEAD. glibc-2.3.2, linux 2.4.22.