[PATCH 1/2] Single thread optimization for malloc atomics

[Rich Felker]

On Wed, Apr 30, 2014 at 04:18:45PM +0200, Ondřej Bílka wrote:
> On Wed, Apr 30, 2014 at 10:57:07AM -0300, Adhemerval Zanella wrote:
> > This patch adds a single-thread optimization for malloc atomic usage to
> > first check if process is single-thread (ST) and if so use normal
> > load/store instead of atomic instructions.
> > 
> How fast is tls on power? When we add a per-thread cache as I suggested
> then it would have most of time same performance as singlethread, with
> overhead one tls variable access per malloc call.

Extremely fast: the TLS address is simply kept in a general-purpose
register.

Rich