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

Allow user to specify list of symbols which cause the dump of callchains
to stop at that symbol.

Committer notes:

Testing it:

  # perf record -ag usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 1.177 MB perf.data (33 samples) ]
  #
  # # Without it:
  #
  # perf script
  swapper   0 [000]  9693.370039:          1 cycles:ppp:
                  2072ad x86_pmu_enable (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a29d7 perf_pmu_enable.part.90 (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a713a ctx_resched (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a76c1 __perf_event_enable (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a0390 event_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a1cff remote_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  326978 flush_smp_call_function_queue (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  327413 generic_smp_call_function_single_interrupt (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  249b37 smp_call_function_single_interrupt (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  a04b2c call_function_single_interrupt (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  889427 cpuidle_enter (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  2e534a call_cpuidle (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  2e5730 cpu_startup_entry (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  9f5167 rest_init (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                 137ffeb start_kernel ([kernel.vmlinux].init.text)
                 137f2ca x86_64_start_reservations ([kernel.vmlinux].init.text)
                 137f419 x86_64_start_kernel ([kernel.vmlinux].init.text)

  swapper   0 [000]  9693.370044:          1 cycles:ppp:
                  20ca1b intel_pmu_handle_irq (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  205b0c perf_event_nmi_handler (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  22a14a nmi_handle (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  22a6b3 default_do_nmi (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  22a83c do_nmi (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  a03fb1 end_repeat_nmi (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a29d7 perf_pmu_enable.part.90 (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a713a ctx_resched (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a76c1 __perf_event_enable (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a0390 event_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a1cff remote_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  326978 flush_smp_call_function_queue (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  327413 generic_smp_call_function_single_interrupt (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  249b37 smp_call_function_single_interrupt (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  a04b2c call_function_single_interrupt (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  889427 cpuidle_enter (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  2e534a call_cpuidle (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  2e5730 cpu_startup_entry (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  9f5167 rest_init (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                 137ffeb start_kernel ([kernel.vmlinux].init.text)
                 137f2ca x86_64_start_reservations ([kernel.vmlinux].init.text)
  #
  # # Using it to see just what are the calls from the 'remote_function' function:
  #
  # perf script --stop-bt remote_function
  swapper   0 [000]  9693.370039:          1 cycles:ppp:
                  2072ad x86_pmu_enable (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a29d7 perf_pmu_enable.part.90 (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a713a ctx_resched (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a76c1 __perf_event_enable (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a0390 event_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a1cff remote_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)

  swapper   0 [000]  9693.370044:          1 cycles:ppp:
                  20ca1b intel_pmu_handle_irq (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  205b0c perf_event_nmi_handler (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  22a14a nmi_handle (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  22a6b3 default_do_nmi (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  22a83c do_nmi (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  a03fb1 end_repeat_nmi (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a29d7 perf_pmu_enable.part.90 (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a713a ctx_resched (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a76c1 __perf_event_enable (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a0390 event_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)
                  3a1cff remote_function (/usr/lib/debug/lib/modules/4.8.8-300.fc25.x86_64/vmlinux)

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1480104021-36275-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Joonwoo reported that there's a mismatch between timestamps in script
and sched commands.  This was because of difference in printing the
timestamp.  Factor out the code and share it so that they can be in
sync.  Also I found that sched map has similar problem, fix it too.

Committer notes:

Fixed the max_lat_at bug introduced by Namhyung's original patch, as
pointed out by Joonwoo, and made it a function following the scnprintf()
model, i.e. returning the number of bytes formatted, and receiving as
the first parameter the object from where the data to the formatting is
obtained, renaming it from:

   char *timestamp_in_usec(char *bf, size_t size, u64 timestamp)

to

   int timestamp__scnprintf_usec(u64 timestamp, char *bf, size_t size)

Reported-by: Joonwoo Park <joonwoop@codeaurora.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20161024020246.14928-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When looking at Intel PT traces with perf script it is useful to have
some indication of the instruction. Dump the instruction bytes and
instruction length, which can be used for simple pattern analysis in
scripts.

% perf record -e intel_pt// foo
% perf script --itrace=i0ns -F ip,insn,insnlen
 ffffffff8101232f ilen: 5 insn: 0f 1f 44 00 00
 ffffffff81012334 ilen: 1 insn: 5b
 ffffffff81012335 ilen: 1 insn: 5d
 ffffffff81012336 ilen: 1 insn: c3
 ffffffff810123e3 ilen: 1 insn: 5b
 ffffffff810123e4 ilen: 2 insn: 41 5c
 ffffffff810123e6 ilen: 1 insn: 5d
 ffffffff810123e7 ilen: 1 insn: c3
 ffffffff810124a6 ilen: 2 insn: 31 c0
 ffffffff810124a8 ilen: 9 insn: 41 83 bc 24 a8 01 00 00 01
 ffffffff810124b1 ilen: 2 insn: 75 87
...

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: http://lkml.kernel.org/r/1475847747-30994-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We're not using it anymore, few users were, but we really could do
without it, simplify lots of functions by removing it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1zng8wdznn00iiz08bb7q3vn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

And remove it from tools/perf/{perf,util}.h, making code that needs
these macros to include linux/time64.h instead, to match how this is
used in the kernel sources.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-e69fc1pvkgt57yvxqt6eunyg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Because perf data from pipe do not have a header with evsel attr, we
should not check that and disable symbol_conf.use_callchain. Otherwise,
perf script won't show callchains even if the data stream contains
callchain.

Before:
  $ perf record -g -o - uname |perf script
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  uname  1828 182630.186578:  250000 cpu-clock:  ..b9499 setup_arg_pages
  uname  1828 182630.186850:  250000 cpu-clock:  ..83b20 ___might_sleep
  uname  1828 182630.187153:  250000 cpu-clock:  ..4b6be file_map_prot_ch
  ...

After:
  $ perf record -g -o - uname |perf script
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  uname  1833 182675.927099:     250000 cpu-clock:
                  ba5520 _raw_spin_lock+0xfe200040 ([kernel.kallsyms])
                  389dd4 expand_downwards+0xfe200154 ([kernel.kallsyms])
                  389f34 expand_stack+0xfe200024 ([kernel.kallsyms])
                  3b957e setup_arg_pages+0xfe20019e ([kernel.kallsyms])
                  40c80f load_elf_binary+0xfe20042f ([kernel.kallsyms])
                  ...

Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470309943-153909-2-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Perf shows the usage message when perf scripts folder failed to open,
which misleads users to let them think the command is being mistyped.

This patch shows a proper message and guides users to check the
PERF_EXEC_PATH environment variable in that case.

Before:

  $ perf script --list

  Usage: perf script [<options>]
   or: perf script [<options>] record <script> [<record-options>] <command>
   or: perf script [<options>] report <script> [script-args]
   or: perf script [<options>] <script> [<record-options>] <command>
   or: perf script [<options>] <top-script> [script-args]

      -l, --list            list available scripts

After:

  $ perf script --list
  open(/home/user/perf-core/scripts) failed.
  Check for "PERF_EXEC_PATH" env to set scripts dir.

Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470309943-153909-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This adds the 'bpf-output' field to the perf script usage message, and docs.

Signed-off-by: Brendan Gregg <bgregg@netflix.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470192469-11910-4-git-send-email-bgregg@netflix.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Based on patches from Andi Kleen.

When printing PT instruction traces with perf script it is rather useful
to see some indentation for the call tree. This patch adds a new
callindent field to perf script that prints spaces for the function call
stack depth.

We already have code to track the function call stack for PT, that we
can reuse with minor modifications.

The resulting output is not quite as nice as ftrace yet, but a lot
better than what was there before.

Note there are some corner cases when the thread stack gets code
confused and prints incorrect indentation. Even with that it is fairly
useful.

When displaying kernel code traces it is recommended to run as root, as
otherwise perf doesn't understand the kernel addresses properly, and may
not reset the call stack correctly on kernel boundaries.

Example output:

	sudo perf-with-kcore record eg2 -a -e intel_pt// -- sleep 1
	sudo perf-with-kcore script eg2 --ns -F callindent,time,comm,pid,sym,ip,addr,flags,cpu --itrace=cre | less
	...
         swapper     0 [000]  5830.389116586:   call        irq_exit                                                     ffffffff8104d620 smp_call_function_single_interrupt+0x30 => ffffffff8107e720 irq_exit
         swapper     0 [000]  5830.389116586:   call            idle_cpu                                                 ffffffff8107e769 irq_exit+0x49 => ffffffff810a3970 idle_cpu
         swapper     0 [000]  5830.389116586:   return          idle_cpu                                                 ffffffff810a39b7 idle_cpu+0x47 => ffffffff8107e76e irq_exit
         swapper     0 [000]  5830.389116586:   call            tick_nohz_irq_exit                                       ffffffff8107e7bd irq_exit+0x9d => ffffffff810f2fc0 tick_nohz_irq_exit
         swapper     0 [000]  5830.389116919:   call                __tick_nohz_idle_enter                               ffffffff810f2fe0 tick_nohz_irq_exit+0x20 => ffffffff810f28d0 __tick_nohz_idle_enter
         swapper     0 [000]  5830.389116919:   call                    ktime_get                                        ffffffff810f28f1 __tick_nohz_idle_enter+0x21 => ffffffff810e9ec0 ktime_get
         swapper     0 [000]  5830.389116919:   call                        read_tsc                                     ffffffff810e9ef6 ktime_get+0x36 => ffffffff81035070 read_tsc
         swapper     0 [000]  5830.389116919:   return                      read_tsc                                     ffffffff81035084 read_tsc+0x14 => ffffffff810e9efc ktime_get
         swapper     0 [000]  5830.389116919:   return                  ktime_get                                        ffffffff810e9f46 ktime_get+0x86 => ffffffff810f28f6 __tick_nohz_idle_enter
         swapper     0 [000]  5830.389116919:   call                    sched_clock_idle_sleep_event                     ffffffff810f290b __tick_nohz_idle_enter+0x3b => ffffffff810a7380 sched_clock_idle_sleep_event
         swapper     0 [000]  5830.389116919:   call                        sched_clock_cpu                              ffffffff810a738b sched_clock_idle_sleep_event+0xb => ffffffff810a72e0 sched_clock_cpu
         swapper     0 [000]  5830.389116919:   call                            sched_clock                              ffffffff810a734d sched_clock_cpu+0x6d => ffffffff81035750 sched_clock
         swapper     0 [000]  5830.389116919:   call                                native_sched_clock                   ffffffff81035754 sched_clock+0x4 => ffffffff81035640 native_sched_clock
         swapper     0 [000]  5830.389116919:   return                              native_sched_clock                   ffffffff8103568c native_sched_clock+0x4c => ffffffff81035759 sched_clock
         swapper     0 [000]  5830.389116919:   return                          sched_clock                              ffffffff8103575c sched_clock+0xc => ffffffff810a7352 sched_clock_cpu
         swapper     0 [000]  5830.389116919:   return                      sched_clock_cpu                              ffffffff810a7356 sched_clock_cpu+0x76 => ffffffff810a7390 sched_clock_idle_sleep_event
         swapper     0 [000]  5830.389116919:   return                  sched_clock_idle_sleep_event                     ffffffff810a7391 sched_clock_idle_sleep_event+0x11 => ffffffff810f2910 __tick_nohz_idle_enter
	...

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1466689258-28493-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>