x86: spinlocks: define dummy __raw_spin_is_contended

Architectures other than mips and x86 are not using ticket spinlocks.
Therefore, the contention on the lock is meaningless, since there is
nobody known to be waiting on it (arguably /fairly/ unfair locks).

Dummy it out to return 0 on other architectures.

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h
index 1a1f320c30d8286cff6d8d16374c9a41fa318ac3..0884947ebe270c404bb293b2acac0b067e7fd9d7 100644 (file)
--- a/arch/mips/include/asm/spinlock.h
+++ b/arch/mips/include/asm/spinlock.h
@@ -51,6 +51,7 @@ static inline int __raw_spin_is_contended(raw_spinlock_t *lock)
 
        return (((counters >> 14) - counters) & 0x1fff) > 1;
 }
+#define __raw_spin_is_contended        __raw_spin_is_contended
 
 static inline void __raw_spin_lock(raw_spinlock_t *lock)
 {

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index ba3e2ff6aedcb1a7c6648acdc9257ad0bb7e3202..c09a1412758431271633f1af7793d708d59a24f2 100644 (file)
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -1402,6 +1402,7 @@ static inline int __raw_spin_is_contended(struct raw_spinlock *lock)
 {
        return PVOP_CALL1(int, pv_lock_ops.spin_is_contended, lock);
 }
+#define __raw_spin_is_contended        __raw_spin_is_contended
 
 static __always_inline void __raw_spin_lock(struct raw_spinlock *lock)
 {

diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h
index d17c91981da2f1c94a5fb045067f821ece61b4fe..8247e94ac6b18dc337f9404cffc97800660c64d8 100644 (file)
--- a/arch/x86/include/asm/spinlock.h
+++ b/arch/x86/include/asm/spinlock.h
@@ -245,6 +245,7 @@ static inline int __raw_spin_is_contended(raw_spinlock_t *lock)
 {
        return __ticket_spin_is_contended(lock);
 }
+#define __raw_spin_is_contended        __raw_spin_is_contended
 
 static __always_inline void __raw_spin_lock(raw_spinlock_t *lock)
 {

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index e0c0fccced46c4b09d654121423f76357407bc95..a0c66a2e00add24f97bfcc908dff123fa4a200c6 100644 (file)
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -124,7 +124,12 @@ do {                                                               \
 #ifdef CONFIG_GENERIC_LOCKBREAK
 #define spin_is_contended(lock) ((lock)->break_lock)
 #else
+
+#ifdef __raw_spin_is_contended
 #define spin_is_contended(lock)        __raw_spin_is_contended(&(lock)->raw_lock)
+#else
+#define spin_is_contended(lock)        (((void)(lock), 0))
+#endif /*__raw_spin_is_contended*/
 #endif
 
 /**