On Thu, Sep 24, 2015 at 07:47:40PM +0000, Liang, Kan wrote: > > > > On Tue, Sep 22, 2015 at 10:13:33AM -0400, kan.li...@intel.com wrote: > > > From: Kan Liang <kan.li...@intel.com> > > > > > > The patch series intends to read counter statistics with fixed > > > frequency during sampling. The instant benefit is that we can read > > > memory bandwidth from uncore event during cpu PMU event is > > sampling. > > > > > > Introduce 'C' event/group modifier. The event with this modifier will > > > do counting not sampling. If a group with this modifier, only group > > > leader do sampling. The counter statistics will be wrote in new RECORD > > > type PERF_RECORD_COUNTER_READ and stored in perf.data. > > > So perf report can present the counter statistics data accordingly. > > > > > > There may be an alternative way to get counter statistics during > > > sampling by running perf record and perf stat together by script. > > > But the script way have various issue and complex to parses the > > > output. > > > > just a thought, but isn't the way then llow to store the data from perf > > stat? ;-) and be able to merge perf.data-s from perf record and stat > > afterwards > > Yes, the way to store the data from perf stat is better than pure script > way. I guess your patch "perf stat record" can do that, right? > > If so, how should we run perf record and stat in parallel? By scripts or > modify perf record/stat? > > Also, we need an option in perf report to merge the perf.data-s. Right?
either that or extra step with 'perf data merge' or somthing like that SNIP > > but if we go this way I think we should keep/allow all the options perf stat > > Do you mean something like "perf record stat"? > That's not the way I designed. I don't want to run perf record and perf stat > together in one command. > > I just want to do similar thing like what sample read did. Sample read can > read > counters on each sample. While the counter read can read counters in a fix yea, but sample read stores data into ring buffer in the kernel while you read the data like in perf stat > frequency (set by --counter-read-interval). So it's an extension of perf > record. > It applies all possible options of perf record, like -C -a -g... > I introduce a new option --counter-read-interval is because that there is no > interval options in perf record. the way I see it you implemented 'perf stat' logic within record command you create counter (non sampling) and read it via read syscall I think it's good idea, but I think we should follow the way we do in perf stat command and reuse the interface (and code) like having the 'stat' keyword separating the non-sampling config: $ perf record -e cycles stat -e 'uncore_imc_1/cas_count_read/' -I 10000 - ./tchain_edit just an idea.. but I dont think the :C modifier is a good way SNIP > > I think we'll need special output/display for non sampling events, > > something like extra window in TUI and distinguished output in stdio, the > > above is hacked sampling output ;-) > > I think it depends on what way we finally use. > > If we use the way which merging perf.data from perf stat and record, I think > we need special output for the data from perf stat in TUI/stdio. > > But if we use the way counter read (:C), I think the best place to show the > counter read results is the header/title (just like the patch did). Because > the > results are the aggregate counts during the whole sampling process. > Something like, > # Event count: 35937 of event 'uncore_imc_1/cas_count_read/C' hum, how the --counter-read-interval data displayed then? it's not single number right? jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
