If you have a very large library or unusual configuration it is possible for SongKong to fail with the error
SongKong is short of memory, task has to be cancelled to prevent further problems Java heap space
On Linux SongKong by default always sets a max use of 900MB of heap memory on Linux, this is lower than other platforms and really should be set to a percentage of total memory.
But you can modify this easily to your preferred value
In your songkong folder you need to edit songkong.sh or songkongremote.sh within it depending on what you use to start SongKong,
First may need to make file writable, e.g
chmod 777 songkong.sh
then open file find the option that says
-Xmx900m
and modify to amount you want to use
e.g
-Xmx3000m
to set to 3GB, this only sets the maximum SongKong may use, not what it will use.