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 cfdf5c322806..706728be312f 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