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18 commits

Author SHA1 Message Date
He Zhe
e49cfed0a8 perf ftrace: Fix failure to set cpumask when only one cpu is present
[ Upstream commit cf30ae726c011e0372fd4c2d588466c8b50a8907 ]

The buffer containing the string used to set cpumask is overwritten at
the end of the string later in cpu_map__snprint_mask due to not enough
memory space, when there is only one cpu.

And thus causes the following failure:

  $ perf ftrace ls
  failed to reset ftrace
  $

This patch fixes the calculation of the cpumask string size.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: dc23103278 ("perf ftrace: Add support for -a and -C option")
Link: http://lkml.kernel.org/r/1564734592-15624-1-git-send-email-zhe.he@windriver.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-29 08:28:46 +02:00
Changbin Du
63cd02d84b perf ftrace: Append an EOL when write tracing files
Before this change, the '--graph-funcs', '--nograph-funcs' and
'--trace-funcs' options didn't work as expected when the <func> doesn't
exist. Because the kernel side hid possible errors.

  $ sudo ./perf ftrace -a --graph-depth 1 --graph-funcs abcdefg
   0)   0.140 us    |  rcu_all_qs();
   3)   0.304 us    |  mutex_unlock();
   0)   0.153 us    |  find_vma();
   3)   0.088 us    |  __fsnotify_parent();
   0)   6.145 us    |  handle_mm_fault();
   3)   0.089 us    |  fsnotify();
   3)   0.161 us    |  __sb_end_write();
   3)   0.710 us    |  SyS_close();
   3)   7.848 us    |  exit_to_usermode_loop();

On the example above, I specified the function filter 'abcdefg' but all
functions are enabled. The expected result is for all functions to be
filtered, since there is no such function ('abcdefg')

The original fix is to make the kernel support '\0' as end of string:
https://lkml.org/lkml/2018/1/16/116

But above fix cannot be compatible with old kernels. Then Namhyung Kim
suggest adding a space after function name.

This patch will append an '\n' when write tracing file. After this fix,
the perf will report correct error state. Also let it print an error if
reset_tracing_files() fails.

Committer testing:

Now it prints:

  # perf ftrace -a --graph-depth 1 --graph-funcs abcdefg
  failed to set tracing filters
  #

And for an existing function:

  # perf ftrace -a --graph-depth 1 --graph-funcs SyS_open
   3)               |  SyS_open() {
   3) ! 494.899 us  |  }
   0) + 23.910 us   |  SyS_open();
   1) + 17.115 us   |  SyS_open();
   1) + 13.900 us   |  SyS_open();
   ------------------------------------------
   3)  qemu-sy-2817  =>  pickup-1290
   ------------------------------------------

   3) + 20.021 us   |  SyS_open();
  #

Signed-off-by: Changbin Du <changbin.du@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1519007609-14551-1-git-send-email-changbin.du@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-02-19 09:49:12 -03:00
Arnaldo Carvalho de Melo
8e99b6d453 tools include: Adopt strstarts() from the kernel
Replacing prefixcmp(), same purpose, inverted result, so standardize on
the kernel variant, to reduce silly differences among tools/ and the
kernel sources, making it easier for people to work in both codebases.

And then doing:

	if (strstarts(option, "no-"))

Looks clearer than doing:

	if (!prefixcmp(option, "no-"))

To figure out if option starts witn "no-".

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kaei42gi7lpa8subwtv7eug8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-07-20 15:46:10 -03:00
Namhyung Kim
1096c35aa8 perf ftrace: Add -D option for depth filter
The -D/--graph-depth option is to set max graph depth.  The following
example traces max 2-depth of page fault handler.

  $ sudo perf ftrace -G __do_page_fault -D 2 -- hello
   ...
   0)               |  __do_page_fault() {
   0)   0.063 us    |    down_read_trylock();
   0)   0.251 us    |    find_vma();
   0)   5.374 us    |    handle_mm_fault();
   0)   0.054 us    |    up_read();
   0)   7.463 us    |  }
   ...

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170618142302.25390-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-19 22:05:54 -03:00
Namhyung Kim
78b83e8b12 perf ftrace: Add option for function filtering
The -T/--trace-funcs and -N/--notrace-funcs options are to specify
functions to enable/disable tracing dynamically.

The -G/--graph-funcs and -g/--nograph-funcs options are to set filters
for function graph tracer.

For example, to trace fault handling functions only:

  $ sudo perf ftrace -T *fault hello
   0)               |  __do_page_fault() {
   0)               |    handle_mm_fault() {
   0)   2.117 us    |      __handle_mm_fault();
   0)   3.627 us    |    }
   0)   7.811 us    |  }
   0)               |  __do_page_fault() {
   0)               |    handle_mm_fault() {
   0)   2.014 us    |      __handle_mm_fault();
   0)   2.424 us    |    }
   0)   2.951 us    |  }
   ...

To trace all functions executed in __do_page_fault:

  $ sudo perf ftrace -G __do_page_fault hello
   2)               |  __do_page_fault() {
   3)   0.060 us    |    down_read_trylock();
   3)               |    find_vma() {
   3)   0.075 us    |      vmacache_find();
   3)   0.053 us    |      vmacache_update();
   3)   1.246 us    |    }
   3)               |    handle_mm_fault() {
   3)   0.063 us    |      __rcu_read_lock();
   3)   0.056 us    |      mem_cgroup_from_task();
   3)   0.057 us    |      __rcu_read_unlock();
   3)               |      __handle_mm_fault() {
   3)               |        filemap_map_pages() {
   3)   0.058 us    |          __rcu_read_lock();
   3)               |          alloc_set_pte() {
   ...

But don't want to show details in handle_mm_fault:

  $ sudo perf ftrace -G __do_page_fault -g handle_mm_fault hello
   3)               |  __do_page_fault() {
   3)   0.049 us    |    down_read_trylock();
   3)               |    find_vma() {
   3)   0.048 us    |      vmacache_find();
   3)   0.041 us    |      vmacache_update();
   3)   0.680 us    |    }
   3)   0.036 us    |    up_read();
   3)   4.547 us    |  } /* __do_page_fault */
   ...

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170618142302.25390-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-19 22:05:53 -03:00
Namhyung Kim
29681bc5bb perf ftrace: Move setup_pager before opening trace_pipe
The 'perf ftrace' command fails to reset tracer after finishing
recording like below:

  $ sudo perf ftrace -v hello
  write 'nop' to tracing/current_tracer failed: Device or resource busy
  ...

This is because the trace_pipe file is open in pager process.  Move the
pager setup to before opening the file.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Fixes: 583359646f ("perf ftrace: Use pager for displaying result")
Link: http://lkml.kernel.org/r/20170618142302.25390-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-19 22:05:52 -03:00
Namhyung Kim
e7bd9ba20a perf ftrace: Show error message when fails to set ftrace files
It'd be better for debugging to show an error message when it fails to
setup ftrace for some reason.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170618142302.25390-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-19 22:05:51 -03:00
Arnaldo Carvalho de Melo
4208735d8d perf tools: Remove poll.h and wait.h from util.h
Not needed in this header, added to the places that need poll(), wait()
and a few other prototypes.

Link: http://lkml.kernel.org/n/tip-i39c7b6xmo1vwd9wxp6fmkl0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-04-24 13:43:34 -03:00
Arnaldo Carvalho de Melo
20a9ed280d perf tools: Use api/fs/tracing_path.h where needed
Instead of getting it out of luck from util.h, where it isn't needed at
all.

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: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-0bqugg5lc5ksla1v4m0dnmc1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-04-19 13:01:54 -03:00
Arnaldo Carvalho de Melo
a43783aeec perf tools: Include errno.h where needed
Removing it from util.h, part of an effort to disentangle the includes
hell, that makes changes to util.h or something included by it to cause
a complete rebuild of the tools.

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: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ztrjy52q1rqcchuy3rubfgt2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-04-19 13:01:51 -03:00
Arnaldo Carvalho de Melo
b0ad8ea664 perf tools: Remove unused 'prefix' from builtin functions
We got it from the git sources but never used it for anything, with the
place where this would be somehow used remaining:

  static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
  {
	prefix = NULL;
	if (p->option & RUN_SETUP)
		prefix = NULL; /* setup_perf_directory(); */

Ditch it.

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: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-uw5swz05vol0qpr32c5lpvus@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-27 11:58:09 -03:00
Namhyung Kim
583359646f perf ftrace: Use pager for displaying result
It's convenient to use the pager when seeing many lines of result.

Note that setup_pager() should be called after perf_evlist__prepare_workload()
since they can interfere each other regarding shared stdio streams.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170224011251.14946-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-03 19:07:17 -03:00
Namhyung Kim
dc23103278 perf ftrace: Add support for -a and -C option
The -a/--all-cpus and -C/--cpu option is for controlling tracing cpus.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170224011251.14946-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-03 19:07:17 -03:00
Namhyung Kim
a9af6be5bc perf ftrace: Add support for --pid option
The -p (--pid) option enables to trace existing process by its pid.

Committer notes:

Testing it:

Using the function_graph tracer on a process that is just waiting for user
input and thus will make 'perf ftrace' sit there waiting for that, then press
any key on that mutt session and see what happens:

  # perf ftrace -t function_graph -p `pidof mutt` | head -40
  2)   1.038 us    |  switch_mm_irqs_off();
  ------------------------------------------
  2)    <idle>-0    =>   mutt-3595
  ------------------------------------------

  2)               |              finish_task_switch() {
  2)               |                smp_irq_work_interrupt() {
  2)               |                  irq_enter() {
  2)   0.180 us    |                    rcu_irq_enter();
  2)   1.248 us    |                  }
  2)               |                  __wake_up() {
  2)   0.126 us    |                    _raw_spin_lock_irqsave();
  2)               |                    __wake_up_common() {
  2)               |                      pollwake() {
  2)               |                        default_wake_function() {
  2)               |                          try_to_wake_up() {
  2)   0.662 us    |                            _raw_spin_lock_irqsave();
  2)               |                            select_task_rq_fair() {
  2)   1.719 us    |                              effective_load.isra.41();
  2)   1.343 us    |                              effective_load.isra.41();
  2)               |                              select_idle_sibling() {
  2)   0.331 us    |                                idle_cpu();
  2)   1.458 us    |                              }
  2)   8.350 us    |                            }
  2)   0.200 us    |                            _raw_spin_lock();
  2)               |                            ttwu_do_activate() {
  2)               |                              activate_task() {
  2)   0.136 us    |                                update_rq_clock.part.77();
  2)               |                                enqueue_task_fair() {
  2)               |                                  enqueue_entity() {
  2)   0.146 us    |                                    update_curr();
  2)   0.330 us    |                                    account_entity_enqueue();
  2)   0.280 us    |                                    update_cfs_shares();
  2)   0.321 us    |                                    place_entity();
  2)   0.206 us    |                                    __enqueue_entity();
  2)   6.926 us    |                                  }
  2)               |                                  enqueue_entity() {
  2)   0.105 us    |                                    update_curr();
  2)   0.175 us    |                                    account_entity_enqueue();
  2)   0.531 us    |                                    update_cfs_shares();
 #

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170224011251.14946-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-03 19:07:16 -03:00
Taeung Song
b05d109398 perf ftrace: Add ftrace.tracer config option
Currently 'perf ftrace' command allows selecting 'function_graph' or
'function', defaulting to 'function_graph'.

Add ftrace.tracer config option to select the default tracer:

    # cat ~/.perfconfig
    [ftrace]
        tracer = function

    # perf ftrace usleep 123456 | head -10
      <...>-14450 [002] d... 10089.284231: finish_task_switch <-__schedule
      <...>-14450 [002] .... 10089.284232: finish_wait <-pipe_wait
      <...>-14450 [002] .... 10089.284232: mutex_lock <-pipe_wait
      <...>-14450 [002] .... 10089.284232: _cond_resched <-mutex_lock

Committer notes:

Retesting it with invalid variables, invalid values for ftrace.tracer,
and a valid one:

  # cat ~/.perfconfig
  [ftrace]
        trace = function
  # perf ftrace usleep 1
  Error: wrong config key-value pair ftrace.trace=function
  # cat ~/.perfconfig
  [ftrace]
        tracer = functin
  # perf ftrace usleep 1
  Please select "function_graph" (default) or "function"
  Error: wrong config key-value pair ftrace.tracer=functin
  # cat ~/.perfconfig
  [ftrace]
        tracer = function
  # perf ftrace usleep 1 | head -5
          <idle>-0     [000] d...  3855.820847: switch_mm_irqs_off <-__schedule
           <...>-18550 [000] d...  3855.820849: finish_task_switch <-__schedule
           <...>-18550 [000] d...  3855.820851: smp_irq_work_interrupt <-irq_work_interrupt
           <...>-18550 [000] d...  3855.820851: irq_enter <-smp_irq_work_interrupt
           <...>-18550 [000] d...  3855.820851: rcu_irq_enter <-irq_enter
  #

Signed-off-by: Taeung Song <treeze.taeung@gmail.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>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1485862711-20216-3-git-send-email-treeze.taeung@gmail.com
[ Added missign space in error message, changed the logic to make it more compact and less error prone ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-31 16:20:09 -03:00
Taeung Song
bf062bd20e perf ftrace: Remove needless code setting default tracer
As a result of commit a3497642c261 ("perf ftrace: Make 'function_graph'
be the default tracer") the ftrace.tracer variable can't be NULL but the
other code setting default tracer remained.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1485423339-22780-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-26 15:53:27 -03:00
Arnaldo Carvalho de Melo
ec347870a9 perf ftrace: Make 'function_graph' be the default tracer
So that we can suppress the '-t function_graph' and get a more compact command
line:

  # perf ftrace usleep 123456 | grep raw_spin_lock | sort -k2 -nr | head -5
  2)   0.555 us    |                _raw_spin_lock();
  2)   0.516 us    |          _raw_spin_lock();
  2)   0.410 us    |          _raw_spin_lock_irq();
  2)   0.374 us    |                        _raw_spin_lock_irqsave();
  #

Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremy Eder <jeder@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ss9xgx5htpxcv86x42pnh3m6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-26 11:43:01 -03:00
Namhyung Kim
d01f4e8db2 perf ftrace: Introduce new 'ftrace' tool
The 'perf ftrace' command is a simple wrapper of kernel's ftrace
functionality.  It only supports single thread tracing currently and
just reads trace_pipe in text and then write it to stdout.

Committer notes:

Testing it:

  # perf ftrace -f function_graph usleep 123456
  <SNIP>
  2)               |  SyS_nanosleep() {
  2)               |    _copy_from_user() {
  <SNIP>
  2)   0.900 us    |      }
  2)   1.354 us    |    }
  2)               |    hrtimer_nanosleep() {
  2)   0.062 us    |      __hrtimer_init();
  2)               |      do_nanosleep() {
  2)               |        hrtimer_start_range_ns() {
  <SNIP>
  2)   5.025 us    |        }
  2)               |        schedule() {
  2)   0.125 us    |          rcu_note_context_switch();
  2)   0.057 us    |          _raw_spin_lock();
  2)               |          deactivate_task() {
  2)   0.369 us    |            update_rq_clock.part.77();
  2)               |            dequeue_task_fair() {
  <SNIP>
  2) + 22.453 us   |            }
  2) + 23.736 us   |          }
  2)               |          pick_next_task_fair() {
  <SNIP>
  2) + 47.167 us   |          }
  2)               |          pick_next_task_idle() {
  <SNIP>
  2)   4.462 us    |          }
  ------------------------------------------
  2)  usleep-20387  =>    <idle>-0
  ------------------------------------------

  2)   0.806 us    |  switch_mm_irqs_off();
  ------------------------------------------
  2)    <idle>-0    =>  usleep-20387
  ------------------------------------------

  2)   0.151 us    |          finish_task_switch();
  2) @ 123597.2 us |        }
  2)   0.037 us    |        _cond_resched();
  2)               |        hrtimer_try_to_cancel() {
  2)   0.064 us    |          hrtimer_active();
  2)   0.353 us    |        }
  2) @ 123605.3 us |      }
  2) @ 123606.2 us |    }
  2) @ 123608.3 us |  } /* SyS_nanosleep */
  2)               |  __do_page_fault() {
 <SNIP>

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremy Eder <jeder@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>,
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-r1hgmsj4dxny8arn3o9mw512@git.kernel.org
[ Various foward port fixes, add man page ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-26 11:43:01 -03:00