Re: Memory leaks / Help with memprof & ps output

[Jason Tackaberry <tack auc ca>]

On Thu, 2002-04-04 at 01:31, Joe Pfeiffer wrote:
> Remember, you're looking at the virtual space, not (necessarily) the
> physical memory.  Unix-related OSes regard virtual space as
> essentially free:  once a process has used to malloc to get some
> virtual space from the OS, it doesn't ever give it back (until the
> process dies, anyway).

Okay, but that's seems inconsistent with this simple malloc test:

    #include <stdio.h>
    #include <glib.h>
    
    void main() {
         char *p = g_new0(char, 1024*1024*100);
         g_print("1. Check memory usage...");
         getchar();
         g_free(p);
         g_print("2. Check again...");
         getchar();
    }

Checking memory usage at (1) shows 100M of RSS, and at (2), shows 600k
or so.  Did I misunderstand you?

What boggles me is that it even works with loading 100M of images with
gdk_pixbuf (in a simple, similar program to the above) in that after I
unref them the RSS drops back down to the original size.  memprof again
shows a big blue bar, and ps shows a sane RSS.  But in my original
program, even though memprof shows all the memory is being freed, my RSS
never drops.  So I'm still confused. ;)

Thanks for your reply,
Jason.