[RFC 00/21] perf tools: Add toggling events support

From: Jiri Olsa
Date: Wed Sep 25 2013 - 08:57:00 EST

sending *RFC* for toggling events support.

Adding perf interface that allows to create toggle events, which can
enable or disable another event. Whenever the toggle event is triggered
(has overflow), it toggles another event state and either starts or
stops it.

The goal is to be able to create toggling tracepoint events to enable and
disable HW counters, but the interface is generic enough to be used for
any kind of event.

It's based on the Frederic's patchset:

Most of the changelogs info is on wiki:

In a nutshell:
The interface is added to the sys_perf_event_open syscall
and new ioctl was added for completeness, check:
perf: Add event toggle sys_perf_event_open interface
perf: Add event toggle ioctl interface

The perf tool interface is pretty rough at the moment. We use
'on' and 'off' terms to specify the toggling event, like:
-e 'cycles,irq_entry/on=cycles/,irq_exit/off=cycles/'

- irq_entry toggles on (starts) cycles, and irq_exit toggled off (stops) cycles.
- cycles is started as paused

Looking forward to some ideas for better interface in here ;-)

The patchset is available at:

thanks for comments,

Define toggle(on/off) events:
# perf probe -a fork_entry=do_fork
# perf probe -a fork_exit=do_fork%return

Following record session samples only within do_fork function:
# perf record -g -e '{cycles,cache-misses}:k,probe:fork_entry/on=cycles/,probe:fork_exit/off=cycles/' \
perf bench sched messaging

Following stat session measure cycles within do_fork function:
# perf stat -e '{cycles,cache-misses}:k,probe:fork_entry/on=cycles/,probe:fork_exit/off=cycles/' \
perf bench sched messaging

# Running sched/messaging benchmark...
# 20 sender and receiver processes per group
# 1 groups == 40 processes run

Total time: 0.073 [sec]

Performance counter stats for './perf bench sched messaging -g 1':

20,935,464 cycles # 0.000 GHz
18,897 cache-misses
40 probe:fork_entry
40 probe:fork_exit

0.086319682 seconds time elapsed

Measure interrupts cycles:
# ./perf stat -e 'cycles,cycles/name=cycles_irq/,irq:irq_handler_entry/on=cycles_irq/,irq:irq_handler_exit/off=cycles_irq/' -a sleep 10

Performance counter stats for 'sleep 10':

50,680,084,994 cycles # 0.000 GHz [100.00%]
652,690 cycles_irq # 0.000 GHz
33 irq:irq_handler_entry [100.00%]
33 irq:irq_handler_exit

10.002084400 seconds time elapsed

Check uprobes example at:

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Don Zickus <dzickus@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Frederic Weisbecker (2):
perf: Be more specific on pmu related event init naming
perf: Split allocation and initialization code

Jiri Olsa (19):
perf tools: Introduce perf_evlist__wait_workload function
perf tools: Separate sys_perf_event_open call into evsel_open
perf x86: Update event count properly for read syscall
perf: Move event state initialization before/behind the pmu add/del calls
perf: Add event toggle sys_perf_event_open interface
perf: Add event toggle ioctl interface
perf: Toggle whole group in toggle event overflow
perf: Add new 'paused' attribute
perf: Account toggle masters for toggled event
perf: Support event inheritance for toggle feature
perf tests: Adding event simple toggling test
perf tests: Adding event group toggling test
perf tests: Adding event inherit toggling test
perf tools: Allow numeric event to change name via name term
perf tools: Add event_config_optional parsing rule
perf tools: Rename term related parsing function/variable properly
perf tools: Carry term string value for symbols events
perf tools: Add support to parse event on/off toggle terms
perf tools: Add record/stat support for toggling events

arch/x86/kernel/cpu/perf_event.c | 6 +-
include/linux/perf_event.h | 12 +++
include/uapi/linux/perf_event.h | 7 +-
kernel/events/core.c | 396 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------
tools/perf/Makefile | 6 ++
tools/perf/arch/x86/tests/toggle-event-raw-64.S | 28 ++++++
tools/perf/builtin-record.c | 7 ++
tools/perf/builtin-stat.c | 12 +++
tools/perf/tests/builtin-test.c | 12 +++
tools/perf/tests/perf-record.c | 1 +
tools/perf/tests/task-exit.c | 5 ++
tools/perf/tests/tests.h | 3 +
tools/perf/tests/toggle-event-group.c | 195 +++++++++++++++++++++++++++++++++++++++++
tools/perf/tests/toggle-event-inherit.c | 132 ++++++++++++++++++++++++++++
tools/perf/tests/toggle-event-raw.c | 106 ++++++++++++++++++++++
tools/perf/util/evlist.c | 97 +++++++++++++++++++++
tools/perf/util/evlist.h | 3 +
tools/perf/util/evsel.c | 53 ++++++-----
tools/perf/util/evsel.h | 4 +
tools/perf/util/parse-events.c | 131 +++++++++++++++++++---------
tools/perf/util/parse-events.h | 9 +-
tools/perf/util/parse-events.l | 6 +-
tools/perf/util/parse-events.y | 68 +++++++++------
tools/perf/util/record.c | 2 +
24 files changed, 1167 insertions(+), 134 deletions(-)
create mode 100644 tools/perf/arch/x86/tests/toggle-event-raw-64.S
create mode 100644 tools/perf/tests/toggle-event-group.c
create mode 100644 tools/perf/tests/toggle-event-inherit.c
create mode 100644 tools/perf/tests/toggle-event-raw.c
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