perf: Tidy up after the big rename

 - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's

 - provide courtesy copy of old perf_counter.h, for user-space projects

 - small indentation fixups

 - fix up MAINTAINERS

 - fix small x86 printout fallout

 - fix up small PowerPC comment fallout (use 'counter' as in register)

Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 27 insertions, 10 deletions

diff --git a/init/Kconfig b/init/Kconfig
index cfdf5c32280..706728be312 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -920,26 +920,31 @@ config HAVE_PERF_EVENTS
 	help
 	  See tools/perf/design.txt for details.
 
-menu "Performance Counters"
+menu "Kernel Performance Events And Counters"
 
 config PERF_EVENTS
-	bool "Kernel Performance Counters"
-	default y if PROFILING
+	bool "Kernel performance events and counters"
+	default y if (PROFILING || PERF_COUNTERS)
 	depends on HAVE_PERF_EVENTS
 	select ANON_INODES
 	help
-	  Enable kernel support for performance counter hardware.
+	  Enable kernel support for various performance events provided
+	  by software and hardware.
 
-	  Performance counters are special hardware registers available
-	  on most modern CPUs. These registers count the number of certain
+	  Software events are supported either build-in or via the
+	  use of generic tracepoints.
+
+	  Most modern CPUs support performance events via performance
+	  counter registers. These registers count the number of certain
 	  types of hw events: such as instructions executed, cachemisses
 	  suffered, or branches mis-predicted - without slowing down the
 	  kernel or applications. These registers can also trigger interrupts
 	  when a threshold number of events have passed - and can thus be
 	  used to profile the code that runs on that CPU.
 
-	  The Linux Performance Counter subsystem provides an abstraction of
-	  these hardware capabilities, available via a system call. It
+	  The Linux Performance Event subsystem provides an abstraction of
+	  these software and hardware cevent apabilities, available via a
+	  system call and used by the "perf" utility in tools/perf/. It
 	  provides per task and per CPU counters, and it provides event
 	  capabilities on top of those.
 
@@ -950,14 +955,26 @@ config EVENT_PROFILE
 	depends on PERF_EVENTS && EVENT_TRACING
 	default y
 	help
-	 Allow the use of tracepoints as software performance counters.
+	 Allow the use of tracepoints as software performance events.
 
-	 When this is enabled, you can create perf counters based on
+	 When this is enabled, you can create perf events based on
 	 tracepoints using PERF_TYPE_TRACEPOINT and the tracepoint ID
 	 found in debugfs://tracing/events/*/*/id. (The -e/--events
 	 option to the perf tool can parse and interpret symbolic
 	 tracepoints, in the subsystem:tracepoint_name format.)
 
+config PERF_COUNTERS
+	bool "Kernel performance counters (old config option)"
+	depends on HAVE_PERF_EVENTS
+	help
+	  This config has been obsoleted by the PERF_EVENTS
+	  config option - please see that one for details.
+
+	  It has no effect on the kernel whether you enable
+	  it or not, it is a compatibility placeholder.
+
+	  Say N if unsure.
+
 endmenu
 
 config VM_EVENT_COUNTERS