Re: [RFC/PATCH 1/2] perf script: Add --time-filter option

From: Namhyung Kim
Date: Wed May 15 2013 - 21:57:05 EST


Hi David,

On Wed, 15 May 2013 09:16:55 -0600, David Ahern wrote:
> On 5/15/13 3:23 AM, Namhyung Kim wrote:
[SNIP]
>> +--time-filter::
>> + Display samples within a range of time only. A time range can be given
>> + like 'time1-time2' and treated as a start time and end time
>> + respectively. The time format is like "<sec>.<usec>". Either of time1
>> + or time2 can be omitted.
>
> I have this option internally on all analysis commands for while now --
> on report, script and my timehist command. Very useful feature.
>
> How about just --time? less typing.

Thanks, I'm fine with '--time' too but '--time-filter' looks more
obvious. What does the timehist command do, btw? ;)

>
>> +
>> SEE ALSO
>> --------
>> linkperf:perf-record[1], linkperf:perf-script-perl[1],
>> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
>> index 92d4658f56fb..fec624b9f8e3 100644
>> --- a/tools/perf/builtin-script.c
>> +++ b/tools/perf/builtin-script.c
>> @@ -28,6 +28,17 @@ static bool system_wide;
>> static const char *cpu_list;
>> static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
>>
>> +#define TIME_FILTER_START 1
>> +#define TIME_FILTER_END 2
>> +
>> +struct time_range {
>> + int filter;
>> + u64 start;
>> + u64 end;
>> +};
>
> The FILTER parts should not be needed.

Right. I'll remove it.

>
>> +
>> +static struct time_range trange;
>> +
>> enum perf_output_field {
>> PERF_OUTPUT_COMM = 1U << 0,
>> PERF_OUTPUT_TID = 1U << 1,
>> @@ -510,6 +521,12 @@ static int process_sample_event(struct perf_tool *tool __maybe_unused,
>> if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
>> return 0;
>>
>> + if ((trange.filter & TIME_FILTER_START) && trange.start > sample->time)
>> + return 0;
>
> How about just:
> if (trange.start && trange.start < sample->time)
> return 0;
>
>> +
>> + if ((trange.filter & TIME_FILTER_END) && trange.end < sample->time)
>> + return 0;
>
> and similarly:
> if (trange.end && trange.end > sample->time)
> return 0;

Okay.

>
>> +
>> scripting_ops->process_event(event, sample, evsel, machine, &al);
>>
>> evsel->hists.stats.total_period += sample->period;
>> @@ -1236,6 +1253,33 @@ static int have_cmd(int argc, const char **argv)
>> return 0;
>> }
>>
>> +static int
>> +parse_time_filter(const struct option *opt, const char *str,
>> + int unset __maybe_unused)
>> +{
>> + struct time_range *time_range = opt->value;
>> + char *sep;
>> +
>> + sep = strchr(str, '-');
>> + if (sep == NULL || sep[1] == '\0') {
>> + time_range->filter = TIME_FILTER_START;
>> + time_range->start = parse_nsec_time(str);
>> + return 0;
>> + } else if (sep == str) {
>> + time_range->filter = TIME_FILTER_END;
>> + time_range->end = parse_nsec_time(++str);
>> + return 0;
>> + }
>> +
>> + *sep++ = '\0';
>> +
>> + time_range->filter = TIME_FILTER_START | TIME_FILTER_END;
>> + time_range->start = parse_nsec_time(str);
>> + time_range->end = parse_nsec_time(sep);
>
> I would expect parse_nsec_time to fail. e.g., a time string like 123455.a

It looks like current strtol() returns 0 when failed to parse like
above. Hmm.. do I have to check whether the return value is 0 or just
ignore invalid inputs?

Thanks,
Namhyung
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