tracing: Add lock-free tracing_map (08d43a5f) · Commits · 戴 / test

Add tracing_map, a special-purpose lock-free map for tracing. tracing_map is designed to aggregate or 'sum' one or more values associated with a specific object of type tracing_map_elt, which is associated by the map to a given key. It provides various hooks allowing per-tracer customization and is separated out into a separate file in order to allow it to be shared between multiple tracers, but isn't meant to be generally used outside of that context. The tracing_map implementation was inspired by lock-free map algorithms originated by Dr. Cliff Click: http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf Link: http://lkml.kernel.org/r/b43d68d1add33582a396f553c8ef705a33a6a748.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by:

kernel/trace/Kconfig

+13 −0

Original line number	Original line	Diff line number	Diff line
	@@ -528,6 +528,19 @@ config MMIOTRACE
	See Documentation/trace/mmiotrace.txt.		See Documentation/trace/mmiotrace.txt.
	If you are not helping to develop drivers, say N.		If you are not helping to develop drivers, say N.

			config TRACING_MAP
			bool
			depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
			default n
			help
			tracing_map is a special-purpose lock-free map for tracing,
			separated out as a stand-alone facility in order to allow it
			to be shared between multiple tracers. It isn't meant to be
			generally used outside of that context, and is normally
			selected by tracers that use it.

			If in doubt, say N.

	config MMIOTRACE_TEST		config MMIOTRACE_TEST
	tristate "Test module for mmiotrace"		tristate "Test module for mmiotrace"
	depends on MMIOTRACE && m		depends on MMIOTRACE && m

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -31,6 +31,7 @@ obj-$(CONFIG_TRACING) += trace_output.o
	obj-$(CONFIG_TRACING) += trace_seq.o		obj-$(CONFIG_TRACING) += trace_seq.o
	obj-$(CONFIG_TRACING) += trace_stat.o		obj-$(CONFIG_TRACING) += trace_stat.o
	obj-$(CONFIG_TRACING) += trace_printk.o		obj-$(CONFIG_TRACING) += trace_printk.o
			obj-$(CONFIG_TRACING_MAP) += tracing_map.o
	obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o		obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
	obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o		obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
	obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o		obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o