From 2c86963b093c1a0887dfc6b32c6e5ea3a80f2922 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Fri, 25 Sep 2009 08:42:16 -0700 Subject: [IA64] implement ticket locks for Itanium Back in January 2008 Nick Piggin implemented "ticket" spinlocks for X86 (See commit 314cdbefd1fd0a7acf3780e9628465b77ea6a836). IA64 implementation has a couple of differences because of the available atomic operations ... e.g. we have no fetchadd2 instruction that operates on a 16-bit quantity so we make ticket locks use a 32-bit word for each of the current ticket and now-serving values. Performance on uncontended locks is about 8% worse than the previous implementation, but this seems a good trade for determinism in the contended case. Performance impact on macro-level benchmarks is in the noise. Signed-off-by: Tony Luck --- arch/ia64/include/asm/spinlock_types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/ia64/include/asm/spinlock_types.h') diff --git a/arch/ia64/include/asm/spinlock_types.h b/arch/ia64/include/asm/spinlock_types.h index 474e46f1ab4a..b61d136d9bc2 100644 --- a/arch/ia64/include/asm/spinlock_types.h +++ b/arch/ia64/include/asm/spinlock_types.h @@ -6,7 +6,7 @@ #endif typedef struct { - volatile unsigned int lock; + volatile unsigned long lock; } raw_spinlock_t; #define __RAW_SPIN_LOCK_UNLOCKED { 0 } -- cgit v1.2.3-59-g8ed1b