Before & After Under The Giant Lock

[Johan Bucht]

2007/11/25, Stephen Montgomery-Smith <stephen at math.missouri.edu>:
>
>
> I just want to add my 2 cents, that my recent experience with FreeBSD MP
> has been extremely positive.  I tend to use highly CPU bound MP programs,
> typically lots and lots of floating point operations.  It used to be that
> Linux beat FreeBSD hands down - now FreeBSD seems to have a slight edge!
> Basically my program runs about twice as fast when I run two threads as
> opposed to one - I cannot see doing any better than that!

Actually, some worksets can get a higher speedup since you usually
double your cache size going from one to two cpus (core 2 duo has a
shared cache). Should the problem be big enough not to fit in one
cpu's cache but small enough to fit in two cpu's caches, you can get
more than 2 times speedup.

/Johan