TSX lock elision for glibc v13

[Carlos O'Donell]

On 06/24/2013 02:24 PM, Andi Kleen wrote:
> All open issues addressed. Some minor fast path optimizations.
> Should be ready for merging now.

We really need to split this up into two different pieces.

* Easy to merge changes that have no ABI/API.

* Changes that make ABI/API changes that we will review
  more thorougly.

I don't see us getting through this much change without
at least splitting it into two pieces like this. Once the
bulk of the changes are merged we can look at the more
difficult parts.
 
That way we can ACK the core bits of the implementation,
for example getting everything in that would allow us to
say use --enable-lock-elision=on and get all default locks
elided with no semantic changes outside of POSIX.

If we do this quick we move into the rest of the implementation
which are things like external types for elision and external
interfaces.

I'm willing to help here if you want to try splitting
this up myself and post a patch set for *you* to review
that shows what I mean by my comments.

Cheers,
Carlos.