XML : R- Parallel Processing taking too much time

i'm running a R script which reads in the values from different(128) Excel sheet(Typically each ranging from 4MB-16MB). The R Script uses a Parallel processing method using Foreach loop wherein it converts the values into respective XML files (in total 128 XMlfiles needs to be generated).

I ran that Script file but it's been 2 days and i got the output for only 12 files.

I would be of great help if anyone can assist me with this as it's quite urgent.