Re: [patch 1/2] Directed yield: cpu_relax variants for spinlocks and rw-locks.

Martin Schwidefsky
2006-09-15T12:06:11Z

On Fri, 2006-09-15 at 21:58 +1000, Paul Mackerras wrote:
> > In order to implement a spinlock that yields the cpu in favour of
> > the current lock holder cpu_relax variants for spinlocks and
> > read/write locks are needed. The new _raw_spin_relax, _raw_read_relax
> > and _raw_write_relax primitives have an additional argument: the
> > pointer to the lock structure.
>
> This will be useful on powerpc as well. We need:
>
> #define _raw_spin_relax(lock) __spin_yield(lock)
> #define _raw_read_relax(lock) __rw_yield(lock)
> #define _raw_write_relax(lock) __rw_yield(lock)
>
> in order to define your new primitives in terms of what we already
> have defined in asm-powerpc/spinlock.h.

Ahh, I haven't seen that powerpc already has a __spin_yield. I'll change
the patch accordingly.

--
blue skies,
Martin.

Martin Schwidefsky
Linux for zSeries Development & Services
IBM Deutschland Entwicklung GmbH

"Reality continues to ruin my life." - Calvin.