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

[Brad Roberts]

On 5/14/2011 7:44 PM, Jonathan M Davis wrote:
> 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

Macro before micro though.