DMD + nedmalloc? last one

[Robert Jacques]

On Fri, 05 Jun 2009 00:31:50 -0400, Jarrett Billingsley  
<jarrett.billingsley at gmail.com> wrote:

> 2009/6/4 davidl <davidl at nospam.org>:
>> attachment 7
>
> Wow, just.. wow.  I can't believe you got it working :D  Thanks so
> much; I'm sure other people will find this useful as well!
>
> At long last, I was able to test it!  And... amazingly, it was 50%
> slower than the default malloc/free :\  I even compiled it with
> optimization enabled.
>
> In disbelief, I tried it in my virtualized linux box with GCC as well,
> and got a similar result, so it doesn't seem to be DMC's fault..
>
> Hm.  Maybe it's just supposed to be faster for multithreaded code.

Well, that's not too surprising. From the little bit on nedmalloc's  
website, it looks like dmd and nedmalloc are using very similar  
algorithms, and D knows you're in a single threaded app, nedmalloc  
doesn't. That said, manual use of nedmalloc should be faster under  
multi-threaded contention, but it's not going to improve the GC since it's  
locking. If you want to improve D's allocation performance, I'd suggest  
looking for and increasing the number of pages grabbed from the OS at any  
one time (it's hopefully a constant somewhere in the GC codebase).