Bartosz Milewski Missing post

[Denis Koroskin]

On Thu, 28 May 2009 20:32:29 +0400, Andrei Alexandrescu <SeeWebsiteForEmail at erdani.org> wrote:

> BCS wrote:
>> Everything is indicating that shared memory multi-threading is where  
>> it's all going.
>
> That is correct, just that it's 40 years late. Right now everything is  
> indicating that things are moving *away* from shared memory.
>
> Andrei

That's true.

For example, we develop for PS3, and its 7 SPU cores have 256KiB of TLS each (which is as fast as L2 cache) and no direct shared memory access. Shared memory needs to be requested via asynchronous memcpy requests, and this scheme doesn't work with OOP well: even after you transfer some object, its vtbl etc still point to shared memory.

We had hard time re-arranging our data so that object and everything it owns (and points to) is stored sequencially in a single large block of memory.
This also resulted in replacing most of the pointers with relative offsets.

Parallelization is hard, but the result is worth the trouble.