[fpc-pascal] EpikTimer v1.0.1 released

[Henry Vermaak]

On Wed, May 28, 2014 at 02:00:06PM +0200, Marco van de Voort wrote:
> > In fact I do want the best possible stuff and not a fork. I am just 
> > trying to help (as I would like to use it in the said current project). 
> 
> In that case some attention points:
> - help implementing and testing fine grained timings on *nix. Now it only has a special
>   case for linux.
> - Seems high precision is not used on anything but x86.
> - Is rdtsc safe for CPUs that can vary clock of cores independently like
>   Core Mono? What if the process changed  CPU to a different clocked core?

- The rdtsc instruction needs to be protected from out of order
  execution.  Some people use cpuid, which is expensive.  It looks like
  the linux kernel uses mfence or lfence/mfence depending on CPU type.