From: Jan Beulich Date: Sun, 17 Aug 2008 00:25:05 +0000 (+0000) Subject: x86: fix spin_is_contended() X-Git-Tag: v2.6.25.16~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=139d09bb6ec8af8de216b0e8b04304d3f5f396bf;p=thirdparty%2Fkernel%2Fstable.git x86: fix spin_is_contended() commit 7bc069c6bc4ede519a7116be1b9e149a1dbf787a upstream 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 Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h index 23804c1890ffc..68d473c26be22 100644 --- a/include/asm-x86/spinlock.h +++ b/include/asm-x86/spinlock.h @@ -75,7 +75,7 @@ static inline int __raw_spin_is_contended(raw_spinlock_t *lock) { int tmp = *(volatile signed int *)(&(lock)->slock); - return (((tmp >> 8) & 0xff) - (tmp & 0xff)) > 1; + return (((tmp >> 8) - tmp) & 0xff) > 1; } static inline void __raw_spin_lock(raw_spinlock_t *lock) @@ -141,7 +141,7 @@ static inline int __raw_spin_is_contended(raw_spinlock_t *lock) { int tmp = *(volatile signed int *)(&(lock)->slock); - return (((tmp >> 16) & 0xffff) - (tmp & 0xffff)) > 1; + return (((tmp >> 16) - tmp) & 0xffff) > 1; } static inline void __raw_spin_lock(raw_spinlock_t *lock)