Maude-help mailing list

[Steven Eker <eker AT csl.sri.com>]

On Monday 27 September 2010 02:25:01 pm Emmanuel Castro wrote:
> It seems that Maude 2 is only able to use one core.
> Is there works in progress about dispatching the rewriting on the 2 or 4
> cores of the modern CPUs?
> 
> Emmanuel
> 

It turns out to be quite tricky to dispatch rewriting over multiple cores - 
if 
all your terms live in the same memory space then you have synchronization 
issues every time you create or overwrite a node. If you care about load 
balancing rather than relying on simple functional parallelism you have more 
synchronization issues. The cost of synchronization can easily eat up any 
benefit of using multiple cores. Multithreaded code is significantly harder 
to 
debug.

That being said, the new rewrite engine I'm working on for Maude 3 will have 
some provision for running on multicore processors, but it will require a 64-
bit address space and use mmap trickery to off load a lot of the 
synchronization to the MMU.

Steven