Messages in this thread | | | From | Namhyung Kim <> | Subject | [RFC 0/3] perf tools: Show time info (v1) | Date | Mon, 2 Dec 2013 15:53:16 +0900 |
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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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