Tom S Wrote: > Jeremie Pelletier wrote: > > Tom S Wrote: > > > >> Jeremie Pelletier wrote: > >>> I myself allocate all my meshes and textures directly on the GC and I'm > >>> pretty sure its faster than C's malloc and much safer. > >> Hm, why would it be faster with the GC than malloc? I'm pretty sure it's > >> the opposite :P Plus, I could use a specialized malloc implementation, > >> like TLSF. > > > > The D GC is already specialized, and given its being used quite a lot in D, > > there are good chances its already sitting in the CPU cache, its heap > > already having the available memory block waiting on a freelist, or if the > > alloc is more than 0x1000 bytes, the pages available in a pool. You'd need > > to use malloc quite a lot to get the same optimal performance, and mixing > > the two would affect the performance of both. > > It might be specialized for _something_, but it definitely isn't > real-time systems. I'd say with my use cases there's a very poor chance > the GC is sitting in the CPU cache since most of the time my memory is > preallocated and managed by specialized structures and/or malloc. I've > found that using the GC only for the hard-to-manually-manage objects > works best. The rest is handled by malloc and the GC has a very shallow > vision of the world thus its collection runs are very fast. Of course > there's a drawback that both the GC and malloc will have some pages > cached, wasting memory, but I don't let the GC touch too much so it > should be minimal. YMMV of course - all depends on the memory allocation > patterns of the application.
I understand your points for using a separate memory manager, and I agree with you that having less active allocations make for faster sweeps, no matter how little of them are scanned for pointers. However I just had an idea on how to implement generational collection on a non-moving GC which should solve your issues (and well, mines too) with the collector not being fast enough. I need to do some hacking on my custom GC first, but I believe it could give yet another performance boost. I'll add my memory manager to my list of code modules to make public :)
