Add a ftrace style --graph-function argument to 'perf script' that
allows to print itrace function calls only below a given function. This
makes it easier to find the code of interest in a large trace.

% perf record -e intel_pt//k -a sleep 1
% perf script --graph-function group_sched_in --call-trace
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])          group_sched_in
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])              __x86_indirect_thunk_rax
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])              event_sched_in.isra.107
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                  perf_event_set_state.part.71
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                      perf_event_update_time
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                  perf_pmu_disable
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                  perf_log_itrace_start
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                  __x86_indirect_thunk_rax
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                      perf_event_update_userpage
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                          calc_timer_values
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                              sched_clock_cpu
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                          __x86_indirect_thunk_rax
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                          arch_perf_update_userpage
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                              __fentry__
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                              using_native_sched_clock
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                              sched_clock_stable
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])                  perf_pmu_enable
            perf   900 [000] 194167.205652203: ([kernel.kallsyms])              __x86_indirect_thunk_rax
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])          group_sched_in
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])              __x86_indirect_thunk_rax
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])              event_sched_in.isra.107
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                  perf_event_set_state.part.71
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                      perf_event_update_time
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                  perf_pmu_disable
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                  perf_log_itrace_start
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                  __x86_indirect_thunk_rax
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                      perf_event_update_userpage
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                          calc_timer_values
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                              sched_clock_cpu
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                          __x86_indirect_thunk_rax
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                          arch_perf_update_userpage
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                              __fentry__
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                              using_native_sched_clock
         swapper     0 [001] 194167.205660693: ([kernel.kallsyms])                              sched_clock_stable

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Kim Phillips <kim.phillips@arm.com>
Link: http://lkml.kernel.org/r/20180920180540.14039-5-andi@firstfloor.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>