From 57f4257eae33e036125973858934730250d464e3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 14 Nov 2013 14:31:54 -0800 Subject: [PATCH] lockref: use BLOATED_SPINLOCKS to avoid explicit config dependencies Avoid the fragile Kconfig construct guestimating spinlock_t sizes; use a friendly compile-time test to determine this. [kirill.shutemov@linux.intel.com: drop CONFIG_CMPXCHG_LOCKREF] Signed-off-by: Peter Zijlstra Signed-off-by: Kirill A. Shutemov Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/lockref.h | 7 ++++++- lib/Kconfig | 7 ------- lib/lockref.c | 2 +- 3 files changed, 7 insertions(+), 9 deletions(-) diff --git a/include/linux/lockref.h b/include/linux/lockref.h index 13dfd36a3294..c8929c3832db 100644 --- a/include/linux/lockref.h +++ b/include/linux/lockref.h @@ -15,10 +15,15 @@ */ #include +#include + +#define USE_CMPXCHG_LOCKREF \ + (IS_ENABLED(CONFIG_ARCH_USE_CMPXCHG_LOCKREF) && \ + IS_ENABLED(CONFIG_SMP) && !BLOATED_SPINLOCKS) struct lockref { union { -#ifdef CONFIG_CMPXCHG_LOCKREF +#if USE_CMPXCHG_LOCKREF aligned_u64 lock_count; #endif struct { diff --git a/lib/Kconfig b/lib/Kconfig index 75485e163ca3..06dc74200a51 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -51,13 +51,6 @@ config PERCPU_RWSEM config ARCH_USE_CMPXCHG_LOCKREF bool -config CMPXCHG_LOCKREF - def_bool y if ARCH_USE_CMPXCHG_LOCKREF - depends on SMP - depends on !GENERIC_LOCKBREAK - depends on !DEBUG_SPINLOCK - depends on !DEBUG_LOCK_ALLOC - config CRC_CCITT tristate "CRC-CCITT functions" help diff --git a/lib/lockref.c b/lib/lockref.c index af6e95d0bed6..d2b123f8456b 100644 --- a/lib/lockref.c +++ b/lib/lockref.c @@ -1,7 +1,7 @@ #include #include -#ifdef CONFIG_CMPXCHG_LOCKREF +#if USE_CMPXCHG_LOCKREF /* * Allow weakly-ordered memory architectures to provide barrier-less