Messages in this thread | | | Date | Mon, 02 Dec 2013 11:35:04 +0200 | From | Pekka Enberg <> | Subject | Re: [RFC 0/3] perf tools: Show time info (v1) |
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On 12/02/2013 08:53 AM, Namhyung Kim wrote: > 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
Reviewed-by: Pekka Enberg <penberg@kernel.org>
for the whole series.
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