diff options
| author |   Tony Luck <tony.luck@intel.com> | 2009-09-25 08:42:16 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2009-09-25 08:42:16 -0700 |
| commit | 2c86963b093c1a0887dfc6b32c6e5ea3a80f2922 (patch) | |
| tree | d1ed58dd0a644dd670e3724a575112fedd4b4250 /arch/ia64/include/asm/spinlock_types.h | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 (diff) | |
| download | linux-dev-2c86963b093c1a0887dfc6b32c6e5ea3a80f2922.tar.xz linux-dev-2c86963b093c1a0887dfc6b32c6e5ea3a80f2922.zip | |
[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 <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/include/asm/spinlock_types.h')
| -rw-r--r-- | arch/ia64/include/asm/spinlock_types.h | 2 |
1 files changed, 1 insertions, 1 deletions
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 } |