From c9f3401313a5089f100d7d1ef4b75cd7b49b2190 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Mon, 18 Jan 2021 22:34:51 +1000 Subject: [PATCH] powerpc: Always enable queued spinlocks for 64s, disable for others Queued spinlocks have shown to have good performance and fairness properties even on smaller (2 socket) POWER systems. This selects them automatically for 64s. For other platforms they are de-selected, the standard spinlock is far simpler and smaller code, and single chips with a handful of cores is unlikely to show any improvement. CONFIG_EXPERT still allows this to be changed, e.g., to help debug performance or correctness issues. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210118123451.1452206-1-npiggin@gmail.com --- arch/powerpc/Kconfig | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 107bb4319e0e0..eebb4a8c156ca 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -505,18 +505,14 @@ config HOTPLUG_CPU Say N if you are unsure. config PPC_QUEUED_SPINLOCKS - bool "Queued spinlocks" + bool "Queued spinlocks" if EXPERT depends on SMP + default PPC_BOOK3S_64 help Say Y here to use queued spinlocks which give better scalability and fairness on large SMP and NUMA systems without harming single threaded performance. - This option is currently experimental, the code is more complex and - less tested so it defaults to "N" for the moment. - - If unsure, say "N". - config ARCH_CPU_PROBE_RELEASE def_bool y depends on HOTPLUG_CPU