Nicholas Piggin <npiggin@xxxxxxxxx> 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@xxxxxxxxx> > --- > 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? > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 24ac85c868db..17663ea57697 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -492,6 +494,17 @@ config HOTPLUG_CPU > > Say N if you are unsure. > > +config PPC_QUEUED_SPINLOCKS > + bool "Queued spinlocks" > + depends on SMP > + default "y" if PPC_BOOK3S_64 Not sure about default y? At least until we've got a better idea of the perf impact on a range of small/big new/old systems. > + help > + Say Y here to use to use queued spinlocks which are more complex > + but give better salability and fairness on large SMP and NUMA > + systems. > + > + If unsure, say "Y" if you have lots of cores, otherwise "N". Would be nice if we could give a range for "lots". > diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild > index dadbcf3a0b1e..1dd8b6adff5e 100644 > --- a/arch/powerpc/include/asm/Kbuild > +++ b/arch/powerpc/include/asm/Kbuild > @@ -6,5 +6,7 @@ generated-y += syscall_table_spu.h > generic-y += export.h > generic-y += local64.h > generic-y += mcs_spinlock.h > +generic-y += qrwlock.h > +generic-y += qspinlock.h The 2nd line spits a warning about a redundant entry. I think you want to just drop it. cheers
