[phobos] Gcx: Would we ever want more than one?

[Jonathan M Davis]

On 2011-05-14 19:09, Brad Roberts wrote:
> On 5/14/2011 7:02 PM, David Simcha wrote:
> > On 5/14/2011 8:28 PM, Sean Kelly wrote:
> >> Technically, you want a free list per core. I don't know how practical
> >> it is to figure that out though.
> >> 
> >> Sent from my iPhone
> > 
> >> On May 12, 2011, at 8:14 PM, David Simcha<dsimcha at gmail.com>  wrote:
> > The idea being that, if you have a free list per core, there will almost
> > never be any contention in practice, even if you have way more threads
> > than cores?
> 
> Ideally neither contention nor cache swapping.  It'd stay in the l1 or l2
> of the core directly involved with the allocations.  By being thread
> centric even if not contended it could still wander between cores and thus
> the caches associated with them.
> 
> A serious micro-optimization, but..

But we're always serious about our micro-optimizations! ;)

Yes, anything which we can reasonably do to make the GC more efficient is a 
good thing. Java already gets enough flak for its GC (most undeservedly at 
this point), and it has an efficient one. We don't. So, anything we can 
reasonably do to improve how well the GC performs is definitely desirable.

- Jonathan M Davis