android_kernel_motorola_sm6225/arch/ia64/oprofile
Tony Luck 2c86963b09 [IA64] implement ticket locks for Itanium
Back in January 2008 Nick Piggin implemented "ticket" spinlocks
for X86 (See commit 314cdbefd1).

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>
2009-09-25 08:42:16 -07:00
..
backtrace.c [IA64] implement ticket locks for Itanium 2009-09-25 08:42:16 -07:00
init.c oprofile: more whitespace fixes 2008-10-15 20:55:51 +02:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfmon.c oprofile: more whitespace fixes 2008-10-15 20:55:51 +02:00