I am running tracker on an 64bits device with 2G of RAM. tracker-extract abort() because malloc() returns NULL while extracting media files. The problem is not that it reached out of memory, but reached the limit of 960M of VIRTUAL memory it sets itself using setrlimit(). If I stop the process in gdb when it aborts, "top" says it's using 962832K of VIRT but only 33288K of RES.

On my ubuntu 15.04 amd64 laptop, "top" says tracker-extract uses 509728K of VIRT and 6648K of RES. This is a lot for a process doing nothing.

Note that the problem is not wasting RAM since it's only virtual memory that the kernel won't count (top still say I have plenty of free memory) but that tracker-extract can easily reach the limit it sets with setrlimit() and then abort.

With pmap <pid>, I see for example 7 mapped blocks like this one:
00007f2550022000  65400K -----   [ anon ]

Note that itc ould be a bug in a library tracker uses for extracting media metadata, like GStreamer.