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authorPeter Zijlstra <peterz@infradead.org>2013-11-14 14:31:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-15 09:32:20 +0900
commit57f4257eae33e036125973858934730250d464e3 (patch)
treef8011cdf5b2e77abb4c721221793d40ed24985a7
parentea1e7ed33708c7a760419ff9ded0a6cb90586a50 (diff)
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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 <peterz@infradead.org> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/lockref.h7
-rw-r--r--lib/Kconfig7
-rw-r--r--lib/lockref.c2
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 <linux/spinlock.h>
+#include <generated/bounds.h>
+
+#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 <linux/export.h>
#include <linux/lockref.h>
-#ifdef CONFIG_CMPXCHG_LOCKREF
+#if USE_CMPXCHG_LOCKREF
/*
* Allow weakly-ordered memory architectures to provide barrier-less