On 07.07.2020 19:05, Jiri Olsa wrote:
> On Tue, Jul 07, 2020 at 05:55:14PM +0300, Alexey Budankov wrote:
>
> SNIP
>
>> process_evlist() now looks suboptimal since record mode code directly calls
>> evlist__ctlfd_process()
>> and then handles returned command specifically to the mode. So in v10 I
>> replaced process_evlist()
>> call with direct evlist__ctlfd_process() call and then handling the returned
>> command by printing
>> command msg tag and counter values in the required order. Like this:
>>
>> + clock_gettime(CLOCK_MONOTONIC, &time_start);
>> + if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll
>> timeout or EINTR */
>> + if (timeout)
>> + break;
>> + else
>> + stop = handle_interval(interval, times);
>> + time_to_sleep = sleep_time;
>> + } else { /* fd revent */
>> + if (evlist__ctlfd_process(evsel_list, &cmd) > 0) {
>> + if (interval) {
>> + switch (cmd) {
>> + case EVLIST_CTL_CMD_ENABLE:
>> + pr_info(EVLIST_ENABLED_MSG);
>> + process_interval();
>> + break;
>> + case EVLIST_CTL_CMD_DISABLE:
>> + process_interval();
>> + pr_info(EVLIST_DISABLED_MSG);
>> + break;
>> + case EVLIST_CTL_CMD_ACK:
>> + case EVLIST_CTL_CMD_UNSUPPORTED:
>> + default:
>> + break;
>> + }
>> + }
>> + }
>> + clock_gettime(CLOCK_MONOTONIC, &time_stop);
>> + compute_tts(&time_start, &time_stop, &time_to_sleep);
>> + }
>
>
> hum, why not just get the bool from process_evlist like below?
Yes, also possible and works. However it checks twice to implement
parts of logically the same work and passes the result using extra
memory: switch/case at process_evlist(), 'if' at dispatch_events(),
dispatch_events() should also call process_interval() instead of
handle_interval() to avoid wasting of times counter for commands.
Alexey
>
> jirka
>
>
> ---
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 5021f7286422..32dd3de93f35 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -485,20 +485,20 @@ 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 display = 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);
> + display = true;
> break;
> case EVLIST_CTL_CMD_DISABLE:
> - stop = handle_interval(interval, times);
> pr_info(EVLIST_DISABLED_MSG);
> + display = true;
> break;
> case EVLIST_CTL_CMD_ACK:
> case EVLIST_CTL_CMD_UNSUPPORTED:
> @@ -507,7 +507,7 @@ static bool process_evlist(struct evlist *evlist,
> unsigned int interval, int *ti
> }
> }
>
> - return stop;
> + return display;
> }
>
> static void enable_counters(void)
> @@ -618,7 +618,8 @@ 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);
> clock_gettime(CLOCK_MONOTONIC, &time_stop);
> diff_timespec(&time_diff, &time_stop, &time_start);
> time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
>
