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authorIngo Molnar <mingo@elte.hu>2009-09-21 12:20:38 +0200
committerIngo Molnar <mingo@elte.hu>2009-09-21 14:34:11 +0200
commit57c0c15b5244320065374ad2c54f4fbec77a6428 (patch)
tree35369d817f5925aca09b083bba47c437b91386d9 /init
parentcdd6c482c9ff9c55475ee7392ec8f672eddb7be6 (diff)
downloadlinaro-lsk-57c0c15b5244320065374ad2c54f4fbec77a6428.tar.gz
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>
Diffstat (limited to 'init')
-rw-r--r--init/Kconfig37
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