Re: hammer: MAP_32BIT

[H. Peter Anvin]

Timothy Miller wrote:
> 
> If your program is capable of handling an address with more than 32
> bits, what point is there giving a hint?  Either your program can handle
> 64-bit pointers or it cannot.  Any program flexible enough to handle
> either size dynamically would expend enough overhead checking that it
> would be worse than if it just made a hard choice.
>

The purpose is that there is a slight task-switching speed advantage if
the address is in the bottom 4 GB.  Since this affects every process,
and most processes use very little TLS, this is worthwhile.

This is fundamentally due to a K8 design flaw.

	-hpa