Hi,
Sometimes users might want to see time information along with the
performance result but the perf cannot provide it currently.
In this patchset, I added such feature using sample->time. When the
perf processes sample events, it calculate time info and update last
timestamp. It keeps the last timestamp for each evsel (and for each
cpu if it's a per-cpu session).
It guesses whether a session is per-cpu if it found PERF_SAMPLE_CPU in
a evsel->attr.sample_type since I couldn't find a better way. However
it'll have a trouble if used with tracepoint events since they require
the cpu info in the sample_type even for the per-thread sessions.
The sample time will usually be proportional to the overhead but
sometimes it show a different result especially in idle state.
With this patch, perf report can show time information in the header
(on --stdio output only for now) and a new column which can be enabled
by --show-time-info option.
$ perf record -- perf bench sched messaging
$ perf report --stdio --show-time-info
# Samples: 10K of event 'cycles'
# Event count (approx.): 5168954556
# Total sampling time : 0.179102 (sec) <--- here
#
# Overhead Time Command Shared Object
Symbol
# ........ .......... ............... ..................
............................
#
6.59% 0.006093 sched-messaging [unknown] [.]
0x0000003153ebc7ed
4.81% 0.005354 sched-messaging [kernel.kallsyms] [k]
copy_user_generic_string
3.89% 0.004098 sched-messaging [kernel.kallsyms] [k]
avc_has_perm_flags
3.77% 0.003630 sched-messaging [kernel.kallsyms] [k]
unix_stream_recvmsg
3.37% 0.003733 sched-messaging [kernel.kallsyms] [k]
_raw_spin_lock
2.97% 0.003489 sched-messaging [kernel.kallsyms] [k]
_raw_spin_lock_irqsave
2.73% 0.002615 sched-messaging [kernel.kallsyms] [k] __slab_free
2.56% 0.002392 sched-messaging [kernel.kallsyms] [k] page_fault
2.45% 0.002572 sched-messaging [kernel.kallsyms] [k]
sock_alloc_send_pskb
I put the series on 'perf/time-sample-v1' branch in my tree:
git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
Any comments are welcome, thanks
Namhyung
Namhyung Kim (3):
perf tools: Record total sampling time
perf tools: Record sampling time for each entry
perf report: Add --show-time-info option
tools/perf/builtin-annotate.c | 2 +-
tools/perf/builtin-diff.c | 2 +-
tools/perf/builtin-report.c | 26 +++++++++++++----
tools/perf/builtin-top.c | 2 +-
tools/perf/tests/hists_link.c | 4 +--
tools/perf/ui/hist.c | 68 ++++++++++++++++++++++++++++++++++++-------
tools/perf/util/evsel.h | 3 ++
tools/perf/util/hist.c | 15 ++++++----
tools/perf/util/hist.h | 4 ++-
tools/perf/util/session.c | 49 +++++++++++++++++++++++++++++++
tools/perf/util/sort.h | 1 +
tools/perf/util/symbol.h | 3 +-
12 files changed, 151 insertions(+), 28 deletions(-)
--
1.7.11.7
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