[Patch] mt_allocator: spare mem & fix alignment problems

[Stefan Olsson]

Paolo Carlini wrote:

> Hi,
>
> the below does two, in principle unrelated, things:
>
>  1- Changes struct block_record to a union: in fact next and
>     thread_id are never used at the same time. The former only
>     when the block is unused and linked to the others of the
>     same thread, the latter only when used. This allows to spare
>     a good amount of memory (see attachments) 

But of course! Do I feel stupid or what?

>
>
>  2- Adds a configurable _M_min_bin, which sets the smallest bin
>     size. The current 1 byte, frankly, doesn't make much sense
>     and, anyway, raising it to 8 bytes allows to fix the alignment
>     problems we were experiencing on ia64 (now the alignment is
>     the same used by default by pool_allocator). 

This has been on my todolist as well. Nice work Paolo!

/Stefan