[PATCH v3 4/6] powerpc/64s: implement queued spinlocks and rwlocks

[Peter Zijlstra]

On Thu, Jul 09, 2020 at 08:20:25PM +1000, Michael Ellerman wrote:
> Nicholas Piggin <npiggin at gmail.com> writes:
> > These have shown significantly improved performance and fairness when
> > spinlock contention is moderate to high on very large systems.
> >
> >  [ Numbers hopefully forthcoming after more testing, but initial
> >    results look good ]
> 
> Would be good to have something here, even if it's preliminary.
> 
> > Thanks to the fast path, single threaded performance is not noticably
> > hurt.
> >
> > Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> > ---
> >  arch/powerpc/Kconfig                      | 13 ++++++++++++
> >  arch/powerpc/include/asm/Kbuild           |  2 ++
> >  arch/powerpc/include/asm/qspinlock.h      | 25 +++++++++++++++++++++++
> >  arch/powerpc/include/asm/spinlock.h       |  5 +++++
> >  arch/powerpc/include/asm/spinlock_types.h |  5 +++++
> >  arch/powerpc/lib/Makefile                 |  3 +++
> 
> >  include/asm-generic/qspinlock.h           |  2 ++
> 
> Who's ack do we need for that part?

Mine I suppose would do, as discussed earlier, it probably isn't
required anymore, but I understand the paranoia of not wanting to change
too many things at once :-)


Acked-by: Peter Zijlstra (Intel) <peterz at infradead.org>