On Mon, Mar 04, 2019 at 08:52:38PM +0800, Jin Yao wrote:
> For better support for perf diff, it would be useful to add --time filter
> option to diff the samples within given time window.
>
> It supports time percent with multipe time ranges. Time string is
> 'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.
>
> For example:
>
> Select the second 10% time slice to diff:
> perf diff --time 10%/2
>
> Select from 0% to 10% time slice to diff:
> perf diff --time 0%-10%
>
> Select the first and the second 10% time slices to diff:
> perf diff --time 10%/1,10%/2
>
> Select from 0% to 10% and 30% to 40% slices to diff:
> perf diff --time 0%-10%,30%-40%
>
> It also supports to analyze samples within given time window as:
> <start>,<stop>. Times have the format seconds.microseconds. If start
> is not given (i.e., time string is ',x.y') then analysis starts at
> the beginning of the file. If stop time is not given (i.e, time
> string is 'x.y,') then analysis goes to end of file. Time string is
> 'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps for different
> perf.data files.
>
> For example, we get the timestamp information from perf script.
>
> perf script -i perf.data.old
> mgen 13940 [000] 3946.361400: ...
>
> perf script -i perf.data
> mgen 13940 [000] 3971.150589 ...
>
> perf diff --time 3946.361400,:3971.150589,
>
> It analyzes the perf.data.old from the timestamp 3946.361400 to
> the end of perf.data.old and analyzes the perf.data from the
> timestamp 3971.150589 to the end of perf.data.
>
> v3:
> ---
> Don't parse the time string if --time option is not set.
> Refactor the code to make it simpler.
it's much clearer now, thanks for doing this, some nits below
SNIP
> +
> static int __cmd_diff(void)
> {
> struct data__file *d;
> int ret = -EINVAL, i;
> + char *abstime_ostr, *abstime_tmp;
> +
> + abstime_ostr = abstime_str_dup();
> + abstime_tmp = abstime_ostr;
could be just one line:
abstime_ostr = abstime_tmp = abstime_str_dup();
also please fail if the allocation fails
>
> data__for_each_file(i, d) {
> - d->session = perf_session__new(&d->data, false, &tool);
> + d->session = perf_session__new(&d->data, false, &pdiff.tool);
> if (!d->session) {
> pr_err("Failed to open %s\n", d->data.path);
> ret = -1;
> goto out_delete;
> }
>
> + if (pdiff.time_str) {
> + ret = parse_time_str(d, abstime_ostr, &abstime_tmp);
> + if (ret < 0)
> + goto out_delete;
> + }
> +
> ret = perf_session__process_events(d->session);
> if (ret) {
> pr_err("Failed to process %s\n", d->data.path);
> @@ -791,6 +889,9 @@ static int __cmd_diff(void)
> }
>
> perf_evlist__collapse_resort(d->session->evlist);
> +
> + if (pdiff.ptime_range)
> + zfree(&pdiff.ptime_range);
> }
>
> data_process();
> @@ -802,6 +903,13 @@ static int __cmd_diff(void)
> }
>
> free(data__files);
> +
> + if (pdiff.ptime_range)
> + zfree(&pdiff.ptime_range);
is this zfree needed? you free it in a loop for every data above
jirka
SNIP
