From cdd6c482c9ff9c55475ee7392ec8f672eddb7be6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 12:02:48 +0200 Subject: perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian Acked-by: Peter Zijlstra Acked-by: Paul Mackerras Reviewed-by: Arjan van de Ven Cc: Mike Galbraith Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Steven Rostedt Cc: Benjamin Herrenschmidt Cc: David Howells Cc: Kyle McMartin Cc: Martin Schwidefsky Cc: "David S. Miller" Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: LKML-Reference: Signed-off-by: Ingo Molnar --- init/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'init/Kconfig') diff --git a/init/Kconfig b/init/Kconfig index 8e8b76d8a272..cfdf5c322806 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -915,17 +915,17 @@ config AIO by some high performance threaded applications. Disabling this option saves about 7k. -config HAVE_PERF_COUNTERS +config HAVE_PERF_EVENTS bool help See tools/perf/design.txt for details. menu "Performance Counters" -config PERF_COUNTERS +config PERF_EVENTS bool "Kernel Performance Counters" default y if PROFILING - depends on HAVE_PERF_COUNTERS + depends on HAVE_PERF_EVENTS select ANON_INODES help Enable kernel support for performance counter hardware. @@ -947,7 +947,7 @@ config PERF_COUNTERS config EVENT_PROFILE bool "Tracepoint profiling sources" - depends on PERF_COUNTERS && EVENT_TRACING + depends on PERF_EVENTS && EVENT_TRACING default y help Allow the use of tracepoints as software performance counters. -- cgit v1.2.2 From 57c0c15b5244320065374ad2c54f4fbec77a6428 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 12:20:38 +0200 Subject: 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 Acked-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- init/Kconfig | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) (limited to 'init/Kconfig') 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 -- cgit v1.2.2