From: Jan Beulich Date: Mon, 4 Aug 2008 13:38:54 +0000 (+0100) Subject: x86: fix spin_is_contended() X-Git-Tag: v2.6.27-rc4~52^2~6 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=7bc069c6bc4ede519a7116be1b9e149a1dbf787a;p=linux-2.6-omap-h63xx.git x86: fix spin_is_contended() The masked difference is what needs to be compared against 1, rather than the difference of masked values (which can be negative). Signed-off-by: Jan Beulich Acked-by: Nick Piggin Cc: Signed-off-by: Ingo Molnar --- diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h index 4f9a9861799..e39c790dbfd 100644 --- a/include/asm-x86/spinlock.h +++ b/include/asm-x86/spinlock.h @@ -65,7 +65,7 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) { int tmp = ACCESS_ONCE(lock->slock); - return (((tmp >> 8) & 0xff) - (tmp & 0xff)) > 1; + return (((tmp >> 8) - tmp) & 0xff) > 1; } static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock) @@ -127,7 +127,7 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) { int tmp = ACCESS_ONCE(lock->slock); - return (((tmp >> 16) & 0xffff) - (tmp & 0xffff)) > 1; + return (((tmp >> 16) - tmp) & 0xffff) > 1; } static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock)