| Message ID | 20210118123451.1452206-1-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] powerpc: always enable queued spinlocks for 64s, disable for others | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (41d8cb7ece7c81e4eb897ed7ec7d3c3d72fd0af4) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 20 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
On Mon, 18 Jan 2021 22:34:51 +1000, Nicholas Piggin wrote: > 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. Applied to powerpc/next. [1/1] powerpc: Always enable queued spinlocks for 64s, disable for others https://git.kernel.org/powerpc/c/c9f3401313a5089f100d7d1ef4b75cd7b49b2190 cheers
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 107bb4319e0e..eebb4a8c156c 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
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 <npiggin@gmail.com> --- Since v1, made the condition simpler as suggested by Christophe. Verified this works as expected for a bunch of old configs (e.g., updates old !EXPERT configs to PPC_QUEUED_SPINLOCKS=y if they were previously =n). Thanks, Nick arch/powerpc/Kconfig | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)