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

Peter Zijlstra
2020-07-09T10:33:47Z

On Thu, Jul 09, 2020 at 08:20:25PM +1000, Michael Ellerman wrote:
> Nicholas Piggin <npiggin@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@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@infradead.org>