Re: [eigen] a branch for SMP (openmp) experimentations

[Mark Borgerding <mark@xxxxxxxxxxxxxx>]

On 02/23/2010 06:34 AM, Aron Ahmadia wrote:
> I'm curious about the difference between OpenMP and pthreads.  I know
> there is a bit of overthread in OpenMP but I didn't realize it would
> be so meaningful.  This will of course vary between architectures and
> compilers,
>    

My experience in a nutshell: OpenMP is elegant, but immature and less 
available compared to pthreads.

At my company, we started using OpenMP but after a while we scrapped it 
in favor of pthreads because of
a) availability  across platforms
b) predictability across platforms
c) major shortcoming uncovered in intel's OpenMP   -- its critical 
section locks are implemented as spinlocks

-- Mark