From b345db9e12089e0221e4ac9e36124affdf879443 Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Sat, 5 Sep 2026 15:29:27 -0400 Subject: [PATCH] alpha: select ARCH_SUPPORTS_ATOMIC_RMW Alpha has native LL/SC instructions (LDL_L/STL_C, LDQ_L/STQ_C) that provide atomic read-modify-write capability, and already selects ARCH_HAVE_NMI_SAFE_CMPXCHG. Selecting ARCH_SUPPORTS_ATOMIC_RMW enables MUTEX_SPIN_ON_OWNER and RWSEM_SPIN_ON_OWNER on SMP, allowing optimistic spinning on contended locks rather than immediately sleeping. Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Matt Turner Tested-by: Magnus Lindholm Reviewed-by: Magnus Lindholm Link: https://lore.kernel.org/r/20260905-arch-kconfig-options-v2-v2-6-83e8245761a2@gmail.com Signed-off-by: Magnus Lindholm --- arch/alpha/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 032c23f979c4..d039b7135d18 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -14,6 +14,7 @@ config ALPHA select ARCH_MODULE_NEEDS_WEAK_PER_CPU if SMP select ARCH_NO_PREEMPT select ARCH_NO_SG_CHAIN + select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_USE_CMPXCHG_LOCKREF select FORCE_PCI select PCI_DOMAINS if PCI