memory problem
Ivan Ramirez wrote on Nov 18, 2009
hi,
i'm having this problem that every time i start to work on fits files with iraf, even if it is only copying them with imcopy, my memory gets used and not returned. example: at some point i have ~1.1gb free but after imcopy-ing something like 20 fits files i end up with 280k and the memory doesn't go back to 1.1gb when it's done. then if i remove the created fits files my memory goes up to 600mb or something but not to 1.1gb again.
any hints?
ivan
i'm having this problem that every time i start to work on fits files with iraf, even if it is only copying them with imcopy, my memory gets used and not returned. example: at some point i have ~1.1gb free but after imcopy-ing something like 20 fits files i end up with 280k and the memory doesn't go back to 1.1gb when it's done. then if i remove the created fits files my memory goes up to 600mb or something but not to 1.1gb again.
any hints?
ivan
Mike Fitzpatrick wrote on Nov 18, 2009
This is normal.
Modern operating systems will usually cache files in memory for faster access and swap them out when the space is needed for something else (this is one reason why writing programs that do entire images in memory aren't necessarily faster than working from 'disk'). When you remove the copied files you removed the cached file from memory as well, most likely the other ~600Mb used is the cached version of the original files (plus space taken by running processes such as the x_images.e binary, cl, etc).
If it's not IRAF, then something else on your machine will fill memory with frequently accessed objects, unless you get an 'out of memory' error or system freeze, don't worry about it.
Modern operating systems will usually cache files in memory for faster access and swap them out when the space is needed for something else (this is one reason why writing programs that do entire images in memory aren't necessarily faster than working from 'disk'). When you remove the copied files you removed the cached file from memory as well, most likely the other ~600Mb used is the cached version of the original files (plus space taken by running processes such as the x_images.e binary, cl, etc).
If it's not IRAF, then something else on your machine will fill memory with frequently accessed objects, unless you get an 'out of memory' error or system freeze, don't worry about it.
Last post on Nov 18, 2009