I am working on some tools written in OCaml (compiled by OCaml version 4.01.0). 

This morning I changed some code, compiled it and let it processing some large data (~ 4G), it never stops after over 2 hours. 

I feed the tool with a tiny input which took less than 1 second to process before, and  I figured out that now it takes around 2.5 minutes before entering into "main" function!

I tried to clean the whole codebase, and recompile it ( I use ocamlbuild 4.01.0), but the same wired situation still happens.. 

I did this:

    ltrace ./init.native input

and I got this output flushing out for a very long time (sorry mail list blocks my large image.. ):