Lightningspeed haskell

Josef Svenningsson josefs@cs.chalmers.se
Wed, 28 Feb 2001 15:04:22 +0100 (MET)


On Wed, 28 Feb 2001, Simon Marlow wrote:

> > It should be noted that synchronisation is achieved by using
> > slightly different kinds of primitives. But still... six times...
>
> And it's about to get faster still, because CVars can now be implemented
> with a single MVar instead of two.  The reason is that putMVar now
> blocks on a full MVar rather than raising an exception.
>
Cool. It'll be interesting to see the speedup.

> But as Simon said, the main reason is surely that GHC is using
> lightweight threads compared to C.  BTW, was this on Linux?  I'd be
> interested to see the results on systems that have different threading
> models, because Linux's threads implementation maps threads onto
> processes (albeit lightweight kind of process, but still a process), so
> the context switch overhead is going to be much higher than a threads
> library which sits in a single process.
>
I don't know what OS he's using. The homepage only says what kind of CPU
and amount of memory his computer has.

	/Josef