Add option to allow user to control analysis window. e.g., collect data
for some amount of time and analyze a segment of interest within that
window.

Committer notes:

Testing it:

  # perf evlist -v
  cycles:ppp: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
  #
  # perf script --hide-call-graph | head -15
    swapper    0 [0] 9693.370039:      1 cycles:ppp: ffffffffb90072ad x86_pmu_enable (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370044:      1 cycles:ppp: ffffffffb900ca1b intel_pmu_handle_irq (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370046:      7 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370048:    126 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370049:   2701 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370051:  58823 cycles:ppp: ffffffffb90cd2e0 idle_cpu (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370059:      1 cycles:ppp: ffffffffb91a713a ctx_resched (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370062:      1 cycles:ppp: ffffffffb900ca1b intel_pmu_handle_irq (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370064:     13 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370065:    250 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370067:   5269 cycles:ppp: ffffffffb902fe79 sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370069: 114602 cycles:ppp: ffffffffb90c1c5a atomic_notifier_call_chain (.../4.8.8-300.fc25.x86_64/vmlinux)
       perf 5124 [2] 9693.370076:      1 cycles:ppp: ffffffffb91a76c1 __perf_event_enable (.../4.8.8-300.fc25.x86_64/vmlinux)
       perf 5124 [2] 9693.370091:      1 cycles:ppp: ffffffffb900ca1b intel_pmu_handle_irq (.../4.8.8-300.fc25.x86_64/vmlinux)
       perf 5124 [2] 9693.370095:      3 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
  #
  # perf script --hide-call-graph --time ,9693.370048
    swapper    0 [0] 9693.370039:      1 cycles:ppp: ffffffffb90072ad x86_pmu_enable (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370044:      1 cycles:ppp: ffffffffb900ca1b intel_pmu_handle_irq (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [0] 9693.370046:      7 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
  # perf script --hide-call-graph --time 9693.370064,9693.370076
    swapper    0 [1] 9693.370064:     13 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370065:    250 cycles:ppp: ffffffffb902fd93 native_sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370067:   5269 cycles:ppp: ffffffffb902fe79 sched_clock (.../4.8.8-300.fc25.x86_64/vmlinux)
    swapper    0 [1] 9693.370069: 114602 cycles:ppp: ffffffffb90c1c5a atomic_notifier_call_chain (.../4.8.8-300.fc25.x86_64/vmlinux)
  #
Signed-off-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1480439746-42695-4-git-send-email-dsahern@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>