Jiri,
On Wed, Sep 25, 2013 at 2:50 PM, Jiri Olsa <jo...@redhat.com> wrote:
> hi,
> 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:
> https://lkml.org/lkml/2011/3/14/346
>
> Most of the changelogs info is on wiki:
> https://perf.wiki.kernel.org/index.php/Jolsa_Features_Togle_Event
>
> 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/'
>
> Meaning:
> - 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:
> git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
> perf/core_toggle
>
> thanks for comments,
Such interface is indeed desirable. I received several requests for
this feature internally and externally.
I think it would need to be generalized for user-level code also, same
user API, different trigger points.
I would assume they would be uprobes instead of tracepoints.
And I agree with you, the current cmdline interface is not good
enough, how about something more
aligned with the current syntax:
-e cpu/event=0x3c,trigger_on=irq_entry,trigger_off=irq_exit/,
Thanks.
> Example:
> 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
>
> Example:
> 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:
> https://perf.wiki.kernel.org/index.php/Jolsa_Features_Togle_Event#Example_-_using_u.28ret.29probes
>
>
> Signed-off-by: Frederic Weisbecker <fweis...@gmail.com>
> Signed-off-by: Jiri Olsa <jo...@redhat.com>
> Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
> Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
> Cc: Frederic Weisbecker <fweis...@gmail.com>
> Cc: Ingo Molnar <mi...@elte.hu>
> Cc: Paul Mackerras <pau...@samba.org>
> Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
> Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
> Cc: Don Zickus <dzic...@redhat.com>
> Cc: Andi Kleen <a...@linux.jf.intel.com>
> Cc: Adrian Hunter <adrian.hun...@intel.com>
> Cc: Stephane Eranian <eran...@google.com>
> ---
> 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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