On 06.07.2020 22:34, Jiri Olsa wrote: > On Mon, Jul 06, 2020 at 05:47:54PM +0300, Alexey Budankov wrote: >> >> On 06.07.2020 15:34, Jiri Olsa wrote: >>> On Fri, Jul 03, 2020 at 10:47:22AM +0300, Alexey Budankov wrote: >>>> >>>> Implement handling of 'enable' and 'disable' control commands >>>> coming from control file descriptor. process_evlist() function >>>> checks for events on control fds and makes required operations. >>>> If poll event splits initiated timeout interval then the reminder >>>> is calculated and still waited in the following poll() syscall. >>>> >>>> Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com> >>>> --- >>>> tools/perf/builtin-stat.c | 75 ++++++++++++++++++++++++++++----------- >>>> 1 file changed, 55 insertions(+), 20 deletions(-) >>>> >>>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c >>>> index 9e4288ecf2b8..5021f7286422 100644 >>>> --- a/tools/perf/builtin-stat.c >>>> +++ b/tools/perf/builtin-stat.c >>>> @@ -485,6 +485,31 @@ static bool handle_interval(unsigned int interval, >>>> int *times) >>>> return false; >>>> } >>>> >>>> +static bool process_evlist(struct evlist *evlist, unsigned int interval, >>>> int *times) >>>> +{ >>>> + bool stop = false; >>>> + enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED; >>>> + >>>> + if (evlist__ctlfd_process(evlist, &cmd) > 0) { >>>> + switch (cmd) { >>>> + case EVLIST_CTL_CMD_ENABLE: >>>> + pr_info(EVLIST_ENABLED_MSG); >>>> + stop = handle_interval(interval, times); >>>> + break; >>>> + case EVLIST_CTL_CMD_DISABLE: >>>> + stop = handle_interval(interval, times); >>> >>> I still don't understand why you call handle_interval in here >>> >>> I don't see it being necessary.. you enable events and handle_interval, >>> wil be called in the next iteration of dispatch_events, why complicate >>> this function with that? >> >> Printing event counts at the moment of command processing lets scripts >> built on top of stat output to provide more plain and accurate metrics. >> Otherwise it may get spikes in the beginning of the next time interval >> because not all counts lay inside [Events enabled, Events disable] >> If -I interval is large tail event count can be also large. Compare the >> output below with the output in the cover letter. Either way is possible >> but the latter one likely complicates the scripts I mentioned above. >> >> perf=tools/perf/perf >> ${perf} stat -D -1 -e cpu-cycles -a -I 1000 \ >> --control fd:${ctl_fd},${ctl_fd_ack} \ >> -- sleep 40 & >> >> Events disabled >> # time counts unit events >> 1.001100723 <not counted> cpu-cycles >> >> 2.003146566 <not counted> cpu-cycles >> >> 3.005073317 <not counted> cpu-cycles >> >> 4.006337062 <not counted> cpu-cycles >> >> Events enabled >> enable acked(ack) >> 5.011182000 54,128,692 cpu-cycles <=== >> >> 6.012300167 3,648,804,827 cpu-cycles >> >> 7.013631689 590,438,536 cpu-cycles >> >> 8.015558583 406,935,663 cpu-cycles >> >> 9.017455505 407,806,862 cpu-cycles >> >> 10.019300780 399,351,824 cpu-cycles >> >> 11.021180025 404,584,417 cpu-cycles >> >> 12.023033661 537,787,981 cpu-cycles >> >> 13.024422354 699,395,364 cpu-cycles >> >> 14.026325749 397,871,324 cpu-cycles >> >> disable acked() >> Events disabled >> 15.027857981 396,956,159 cpu-cycles <=== >> 16.029279264 <not counted> cpu-cycles >> >> 17.031131311 <not counted> cpu-cycles >> >> 18.033010580 <not counted> cpu-cycles >> >> 19.034918883 <not counted> cpu-cycles >> >> enable acked(ack) >> Events enabled >> 20.036758793 183,544,975 cpu-cycles <=== >> >> 21.038163289 419,054,544 cpu-cycles >> >> 22.040108245 413,993,309 cpu-cycles >> >> 23.042042365 403,584,493 cpu-cycles >> >> 24.043985381 416,512,094 cpu-cycles >> >> 25.045925682 401,513,429 cpu-cycles >> >> # time counts unit events >> 26.047822238 461,205,096 cpu-cycles >> >> 27.049784263 414,319,162 cpu-cycles >> >> 28.051745360 403,706,915 cpu-cycles >> >> 29.053674600 416,502,883 cpu-cycles >> >> disable acked() >> Events disabled >> 30.054750685 414,184,409 cpu-cycles <=== > > ok, but we could still take handle_interval out of process_evlist > and the interval process will be more clear for me (with some > additional comments in the code) ... perhaps something like below? > > thanks, > jirka > > > --- > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 5021f7286422..af83bf6b2db0 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -485,19 +485,18 @@ static bool handle_interval(unsigned int interval, int > *times) > return false; > } > > -static bool process_evlist(struct evlist *evlist, unsigned int interval, int > *times) > +static bool process_evlist(struct evlist *evlist) > { > - bool stop = false; > enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED; > + bool enabled = false; > > if (evlist__ctlfd_process(evlist, &cmd) > 0) { > switch (cmd) { > case EVLIST_CTL_CMD_ENABLE: > pr_info(EVLIST_ENABLED_MSG); > - stop = handle_interval(interval, times); > + enabled = true; > break; > case EVLIST_CTL_CMD_DISABLE: > - stop = handle_interval(interval, times); > pr_info(EVLIST_DISABLED_MSG); > break; > case EVLIST_CTL_CMD_ACK: > @@ -507,7 +506,7 @@ static bool process_evlist(struct evlist *evlist, > unsigned int interval, int *ti > } > } > > - return stop; > + return enabled; > } > > static void enable_counters(void) > @@ -618,7 +617,8 @@ static int dispatch_events(bool forks, int timeout, int > interval, int *times) > stop = handle_interval(interval, times); > time_to_sleep = sleep_time; > } else { /* fd revent */ > - stop = process_evlist(evsel_list, interval, times); > + if (process_evlist(evsel_list)) > + stop = handle_interval(interval, times);
It will call only on enable command and lead to artificial spikes in the beginning of interval. May be just take handle_interval() out of process_evlist() and have it similar to record case? Alexey