parallel cost-centre profiling

[Henrique Ferreiro]

Hello!

I am trying to make cost centre profiling work in the threaded rts
build in order to use that information to better understand parallel
behaviour.

Currently I am learning about the internals of GHC and I am thinking
about how this could be done. The main blocker is that the current
cost centre stack is a shared global variable. The simplest solution I
came up with is to convert it to a thread local variable. The problem
would be how to access it from the global timer.

As I don't have the full picture yet, I would greatly appreciate if
some of you could give me some advice on how to tackle this problem.
Would it be possible to use thread local storage for this? Is there a
better design?

Thanks in advance.

Cheers,

Henrique.