[Kstars-devel] more on memory usage

[Jason Harris]

Hello,

The mystery continues.  I am attempting to get a more precise measurement of 
the memory usage by examining the file /proc/[kstars-pid]/status.  This file 
describes the memory usage in several ways:

VmExe = the executable
VmLib = libraries (?)
VmRSS = includes shared libraries
VmData = size of data used by program (this is what we need!)
VmSize = the grand total

With all 125,994 stars loaded, VmData = 97380 kB
With 4 stars loaded (mag<0.0) VmData = 19420 kB
With 15 stars loaded (mag < 1.0) VmData = 20292 kB

We can compute the memory used per-star by looking at the differences of these 
three instances:

125,990 stars = (97380-19420) = 77960 kB --> 0.618 kB per star
11 stars = (20292 -  19420) = 872 kB --> 79 kB per star!!

Something is wrong here.  I thought it must be the additional memory of the 
star names, but when I use an alternate version of the star catalog for hich 
names have been removed, VmData is 19368, which is only 52 kB less than 
before.  This implies that the names take about 13 kB per star, not even 
close to 79 kB.  

I am puzzled.

BTW, I think someone mentioned it before, but I am noticing that loading 
additional stars by increasing the faint limit while the program is running 
does not currently work.  We will need to fix that by release.

-- 
KStars:  A K Desktop Planetarium
http://edu.kde.org/kstars