From: Matt Turner <mattst88@gmail.com>
To: Magnus Lindholm <linmag7@gmail.com>
Cc: linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org,
Matt Turner <mattst88@gmail.com>
Subject: [PATCH] alpha: Select ARCH_SUPPORTS_ATOMIC_RMW
Date: Fri, 3 Apr 2026 11:03:29 -0400 [thread overview]
Message-ID: <20260403150340.489381-1-mattst88@gmail.com> (raw)
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 <mattst88@gmail.com>
---
arch/alpha/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git ./arch/alpha/Kconfig ./arch/alpha/Kconfig
index 4329743757e3..57c91ed67b71 100644
--- ./arch/alpha/Kconfig
+++ ./arch/alpha/Kconfig
@@ -10,6 +10,7 @@ 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_SUPPORTS_PAGE_TABLE_CHECK
select ARCH_USE_CMPXCHG_LOCKREF
select FORCE_PCI
--
2.52.0
reply other threads:[~2026-04-03 15:03 UTC|newest]
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