Runtime performance degradation for multi-threaded C FFI callback

[Daniel Fischer]

On Monday 23 January 2012, 14:26:13, Simon Marlow wrote:
> Another possibility is a difference in OS scheduling behaviour between 
> yours and Daniel Fischer's setup.  In microbenchmarks like this, it's 
> easy for a difference in OS scheduling behaviour to make a large 
> difference in performance if it happens consistently.

That seems likely, since I get pretty much the same times and relations 
with 7.0.4 and 7.2.1 as with 7.2.2

Cheers,
Daniel