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/kernel/ia64_ksyms.c | 20 -------------------- 1 file changed, 20 deletions(-) (limited to 'arch/ia64/kernel/ia64_ksyms.c') diff --git a/arch/ia64/kernel/ia64_ksyms.c b/arch/ia64/kernel/ia64_ksyms.c index 8ebccb589e1c..14d39e300627 100644 --- a/arch/ia64/kernel/ia64_ksyms.c +++ b/arch/ia64/kernel/ia64_ksyms.c @@ -84,26 +84,6 @@ EXPORT_SYMBOL(ia64_save_scratch_fpregs); #include EXPORT_SYMBOL(unw_init_running); -#ifdef ASM_SUPPORTED -# ifdef CONFIG_SMP -# if (__GNUC__ == 3 && __GNUC_MINOR__ < 3) -/* - * This is not a normal routine and we don't want a function descriptor for it, so we use - * a fake declaration here. - */ -extern char ia64_spinlock_contention_pre3_4; -EXPORT_SYMBOL(ia64_spinlock_contention_pre3_4); -# else -/* - * This is not a normal routine and we don't want a function descriptor for it, so we use - * a fake declaration here. - */ -extern char ia64_spinlock_contention; -EXPORT_SYMBOL(ia64_spinlock_contention); -# endif -# endif -#endif - #if defined(CONFIG_IA64_ESI) || defined(CONFIG_IA64_ESI_MODULE) extern void esi_call_phys (void); EXPORT_SYMBOL_GPL(esi_call_phys); -- cgit v1.2.2