Generalize existing macros to serve the purpose.
Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1462461799-17518-1-git-send-email-naveen.n.rao@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

That field is only updated when we use the "sched:sched_stat_runtime"
tracepoint, and that is only done so far when we use the '--stat' command line
option, without it we get just zeros, confusing the users:

Without this patch:

  # trace -a -s sleep 1
  <SNIP>
   qemu-system-x86 (9931), 468 events, 9.6%, 0.000 msec

     syscall     calls    total       min       avg       max      stddev
                          (msec)    (msec)    (msec)    (msec)        (%)
     ---------- ------ --------- --------- --------- ---------     ------
     ppoll          98   982.374     0.000    10.024    29.983     12.65%
     write          34     0.401     0.005     0.012     0.027      5.49%
     ioctl         102     0.347     0.002     0.003     0.007      3.08%

   firefox (10871), 1856 events, 38.2%, 0.000 msec

                          (msec)    (msec)    (msec)    (msec)        (%)
     ---------- ------ --------- --------- --------- ---------     ------
     poll          395   934.873     0.000     2.367    17.120     11.51%
     recvmsg       395     0.988     0.001     0.003     0.021      4.20%
     read          106     0.460     0.002     0.004     0.007      3.17%
     futex          24     0.108     0.001     0.004     0.010     10.05%
     mmap            2     0.041     0.016     0.021     0.026     23.92%
     write           6     0.027     0.004     0.004     0.005      2.52%

After this patch that ', 0.000 msecs' gets suppressed when --stat is not
in use.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-p7emqrsw7900tdkg43v9l1e1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

  # trace -a -s sleep 1
  <SNIP>
   Xorg (1965), 788 events, 19.0%, 0.000 msec

     syscall            calls    total       min       avg       max      stddev
                                 (msec)    (msec)    (msec)    (msec)        (%)
     --------------- -------- --------- --------- --------- ---------     ------
     select                89   731.038     0.000     8.214   175.218     36.71%
     ioctl                 22     0.661     0.010     0.030     0.072     10.43%
     writev                42     0.253     0.002     0.006     0.011      5.94%
     recvmsg               60     0.185     0.001     0.003     0.009      5.90%
     setitimer             60     0.127     0.001     0.002     0.006      6.14%
     read                  52     0.102     0.001     0.002     0.005      8.55%
     rt_sigprocmask        45     0.092     0.001     0.002     0.023     23.65%
     poll                  12     0.021     0.001     0.002     0.003      7.21%
     epoll_wait            12     0.019     0.001     0.002     0.002      2.71%

   firefox (10871), 1080 events, 26.1%, 0.000 msec

     syscall            calls    total       min       avg       max      stddev
                                 (msec)    (msec)    (msec)    (msec)        (%)
     --------------- -------- --------- --------- --------- ---------     ------
     poll                 240   979.562     0.000     4.082    17.132     11.33%
     recvmsg              240     0.532     0.001     0.002     0.007      3.69%
     read                  60     0.303     0.003     0.005     0.029      8.50%
Suggested-by: NMilian Wolff <milian.wolff@kdab.com>
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-52kdkuyxihq0kvc0n2aalhay@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

  # trace -a -s sleep 1 |& grep events | tail
   gmain (1733), 34 events, 1.0%, 0.000 msec
   hexchat (9765), 46 events, 1.4%, 0.000 msec
   ssh (11109), 80 events, 2.4%, 0.000 msec
   sleep (32631), 81 events, 2.4%, 0.000 msec
   qemu-system-x86 (10021), 272 events, 8.2%, 0.000 msec
   Xorg (1965), 322 events, 9.7%, 0.000 msec
   SoftwareVsyncTh (10922), 366 events, 11.1%, 0.000 msec
   gnome-shell (2231), 446 events, 13.5%, 0.000 msec
   qemu-system-x86 (9931), 468 events, 14.1%, 0.000 msec
   firefox (10871), 1098 events, 33.2%, 0.000 msec
  [root@jouet ~]#
Suggested-by: NMilian Wolff <milian.wolff@kdab.com>
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-ye4cnprhfeiq32ar4lt60dqs@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Sometimes we want to sort an existing rbtree by a different key,
introduce a template for that, that needs only to be provided the
rbtree root and the number of entries in it.

To do that a new rbtree will be created with extra space for each entry,
where possibly pre-calculated keys will be stored to be used in the
resort process and also later, when using the newly sorted rbtree.

Please check the following two changesets to see it in use for resorting
stats for threads and its syscalls in 'perf trace --summary'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9l6e1q34lmf3wwdeewstyakg@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To be used, for instance, for pre-allocating an rb_tree array for
sorting by other keys besides the current pid one.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ja0ifkwue7ttjhbwijn6g6eu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Using sizeof on a malloced pointer type will return the wordsize which
can often cause one to allocate a buffer much smaller than it is needed.
So, here do not use sizeof on pointer type.

Note that this has no effect on runtime because 'dsos' is a pointer to a
pointer.

Problem found using Coccinelle.
Signed-off-by: NVaishali Thakkar <vaishali.thakkar@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461862017-23358-1-git-send-email-vaishali.thakkar@oracle.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the size of builtin-trace.c.

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-11zxg3qitk6bw2x30135k9z4@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

With 'perf record --switch-output' without -a, record__synthesize() in
record__switch_output() won't generate tracking events because there's
no thread_map in evlist. Which causes newly created perf.data doesn't
contain map and comm information.

This patch creates a fake thread_map and directly call
perf_event__synthesize_thread_map() for those events.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-8-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The cost of buildid cache processing is high: reading all events in
output perf.data, opening each elf file to read buildids then copying
them into ~/.debug directory. In switch output mode, these heavy works
block perf from receiving perf events for too long.

Enable no-buildid and no-buildid-cache by default if --switch-output is
provided. Still allow user use --no-no-buildid to explicitly enable
buildid in this case.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-6-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com>
[ Updated man page ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Without this patch, the last output doesn't have timestamp appended if
--timestamp-filename is not explicitly provided. For example:

  # perf record -a --switch-output &
  [1] 11224
  # kill -s SIGUSR2 11224
  [ perf record: dump data: Woken up 1 times ]
  # [ perf record: Dump perf.data.2015122622372823 ]

  # fg
  perf record -a --switch-output
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.027 MB perf.data (540 samples) ]

  # ls -l
  total 836
  -rw------- 1 root root  33256 Dec 26 22:37 perf.data   <---- *Odd*
  -rw------- 1 root root 817156 Dec 26 22:37 perf.data.2015122622372823
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-5-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com>
[ Updated man page, that also got an entry for --timestamp-filename ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Allow 'perf record' to split its output into multiple files.

For example:

  # ~/perf record -a --timestamp-filename --switch-output &
  [1] 10763
  # kill -s SIGUSR2 10763
  [ perf record: dump data: Woken up 1 times ]
  # [ perf record: Dump perf.data.2015122622314468 ]

  # kill -s SIGUSR2 10763
  [ perf record: dump data: Woken up 1 times ]
  # [ perf record: Dump perf.data.2015122622314762 ]

  # kill -s SIGUSR2 10763
  [ perf record: dump data: Woken up 1 times ]
  #[ perf record: Dump perf.data.2015122622315171 ]

  # fg
  perf record -a --timestamp-filename --switch-output
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Dump perf.data.2015122622315513 ]
  [ perf record: Captured and wrote 0.014 MB perf.data.<timestamp> (296 samples) ]

  # ls -l
  total 920
  -rw------- 1 root root 797692 Dec 26 22:31 perf.data.2015122622314468
  -rw------- 1 root root  59960 Dec 26 22:31 perf.data.2015122622314762
  -rw------- 1 root root  59912 Dec 26 22:31 perf.data.2015122622315171
  -rw------- 1 root root  19220 Dec 26 22:31 perf.data.2015122622315513
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-4-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com>
[ Added man page entry, used the re-synthesize patch in this series as a fixup ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

auxtrace_snapshot_state matches the trigger model. Use trigger to
implement it. auxtrace_snapshot_state and auxtrace_snapshot_err are
absorbed.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-3-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Use 'trigger' to model operations which need to be executed when an
event (a signal, for example) is observed.

States and transits:

 OFF--(on)--> READY --(hit)--> HIT
		^               |
		|            (ready)
		|               |
		 \_____________/

is_hit and is_ready are two key functions to query the state of a
trigger. is_hit means the event already happen; is_ready means the
trigger is waiting for the event.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-2-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Replace many fixed-length char array with strbuf to stringify
perf_probe_event and probe_trace_event etc.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160427183713.23446.97377.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The error messages returned by this method should not have an ending
newline, fix the two cases where it was.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-8af0pazzhzl3dluuh8p7ar7p@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When the kernel allows tweaking perf_event_max_stack and the event being
setup has PERF_SAMPLE_CALLCHAIN in its perf_event_attr.sample_type, tell
the user that tweaking /proc/sys/kernel/perf_event_max_stack may solve
the problem.

Before:

  # echo 32000 > /proc/sys/kernel/perf_event_max_stack
  # perf record -g usleep 1
  Error:
  The sys_perf_event_open() syscall returned with 12 (Cannot allocate memory) for event (cycles:ppp).
  /bin/dmesg may provide additional information.
  No CONFIG_PERF_EVENTS=y kernel support configured?

  #

After:

  # echo 64000 > /proc/sys/kernel/perf_event_max_stack
  # perf record -g usleep 1
  Error:
  Not enough memory to setup event with callchain.
  Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack
  Hint: Current value: 64000
  #
Suggested-by: NDavid Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ebv0orelj1s1ye857vhb82ov@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Propagate the error instead.

Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
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-z6erjg35d1gekevwujoa0223@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Introduced in commit 4babf2c5 ("x86: wire up preadv2 and pwritev2").

This will make 'perf trace' aware of them.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-vojoylgce2cetsy36446s5ny@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Perf is not able to register probe in kernel module when dwarf supprt
is not there(and so it goes for symtab). Perf passes full path of
module where only module name is required which is causing the problem.
This patch fixes this issue.

Before applying patch:

  $ dpkg -s libdw-dev
  dpkg-query: package 'libdw-dev' is not installed and no information is...

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init (on kprobe_init in /linux/samples/kprobes/kprobe_example.ko)

  You can now use it in all perf tools, such as:

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init /linux/samples/kprobes/kprobe_example.ko:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data ]

  $ sudo ./perf script 	# No output here

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init    (on kprobe_init in kprobe_example)

  You can now use it in all perf tools, such as:

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init kprobe_example:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data (2 samples) ]

  $ sudo ./perf script
  insmod 13990 [002]  5961.216833: probe:kprobe_init: ...
  insmod 13995 [002]  5962.889384: probe:kprobe_init: ...
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-1-git-send-email-ravi.bangoria@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Perf can add a probe on kernel module which has not been loaded yet.

The current implementation finds the module name from path. But if the
filename is different from the actual module name then perf fails to
register a probe while loading module because of mismatch in the names.

For example, samples/kobject/kobject-example.ko is loaded as
kobject_example.

Before applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject-example)

    You can now use it in all perf tools, such as:

    perf record -e probe:foo_show -aR sleep 1

  $ cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject-example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.093 MB perf.data ]

  $./perf report --stdio -F overhead,comm,dso,sym
    Error:
    The perf.data.old file has no samples!

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject_example)

    You can now use it in all perf tools, such as:

    perf record -e probe:foo_show -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject_example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.097 MB perf.data (8 samples) ]

  $ sudo ./perf report  --stdio -F overhead,comm,dso,sym
    ...
    # Samples: 8  of event 'probe:foo_show'
    # Event count (approx.): 8
    #
    # Overhead  Command  Shared Object      Symbol
    # ........  .......  .................  ............
    #
       100.00%  cat      [kobject_example]  [k] foo_show
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-2-git-send-email-ravi.bangoria@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We get notifications for threads that gets created while we're tracing,
but for preexisting threads we may end not having synthesized them, like
when tracing a 'perf trace' session that will use '--pid' to trace some
other thread.

And besides we should probably stop synthesizing those records and
instead read thread information in a lazy way, i.e. just when we need,
like done in this patch:

Now the 'pid_t' argument in 'perf_event_open' gets translated to a COMM:

  # perf trace -e perf_event_open perf stat -e cycles -p 31601
     0.027 ( 0.027 ms): perf/23393 perf_event_open(attr_uptr: 0x2fdd0d8, pid: 31601 (abrt-dump-journ), cpu: -1, group_fd: -1, flags: FD_CLOEXEC)
                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= 3
^C

And in other syscalls containing pid_t without thread->comm_set at the
time of the formatting.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ioeps6dlwst17d6oozc9shtk@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Will be used for lazy comm loading in 'perf trace'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-7ogbkuoka1y2qsmcckqxvl5m@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Leave it alone so that it ends up assigned to SCA_PID via its type,
'pid_t', that will look up the pid on the machine thread rb_tree and
possibly find its COMM.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-r7dujgmhtxxfajuunpt1bkuo@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the size of builtin-trace.c.

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-8r3gmymyn3r0ynt4yuzspp9g@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Set kprobe group name as "probe" if it is not given.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090413.11891.95640.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since other methods return 0 if succeeded (or filedesc), let
probe_file__add_event() return 0 instead of the length of written bytes.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090303.11891.18232.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As a utility function, add lsdir() which reads given directory and store
entry name into a strlist.  lsdir accepts a filter function so that user
can filter out unneeded entries.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090242.11891.79014.stgit@devbox
[ Do not use the 'dirname' it is used in some distros ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix a bug to close target elf file in get_text_start_address().
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426064737.1443.44093.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Don't read broken data after 'head' pointer.

Following commits will feed perf_evlist__mmap_read() with some 'head'
pointers not maintained by kernel. If 'head' pointer breaks an event, we
should avoid reading from the broken event. This can happen in backward
ring buffer.

For example:

                              old     head
                                |     |
                                V     V
     +---+------+----------+----+-----+--+
     |..E|D....D|C........C|B..B|A....|E.|
     +---+------+----------+----+-----+--+

'old' pointer points to the beginning of 'A' and trying read from it,
but 'A' has been overwritten. In this case, don't try to read from 'A',
simply return NULL.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461637738-62722-2-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The accumulated period for dummy entry should also be 0.  Otherwise, the
total overhead could be overcounted.

  $ perf record -e '{LLC-load-misses,cpu/instructions/}' --call-graph=lbr ./tchain
  $ perf report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 21K of event 'anon group { LLC-load-misses, cpu/instructions/ }'
  # Event count (approx.): 16313667937
  #
  #         Children              Self  Command      Shared Object     Symbol
  # ................  ................  ...........  ................  ............................
  #
    4769.98%   0.01%     0.00%   0.01%  tchain_edit  [kernel.vmlinux]  [k] update_fast_timekeeper
    4356.18%   0.01%     0.00%   0.01%  tchain_edit  [kernel.vmlinux]  [k] trigger_load_balance
    3181.12%   0.01%     0.00%   0.01%  tchain_edit  [kernel.vmlinux]  [k] irq_work_tick
    1592.37%   0.00%     0.00%   0.00%  tchain_edit  [kernel.vmlinux]  [k] cpu_needs_another_gp
Signed-off-by: NKan Liang <kan.liang@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1461565689-5862-1-git-send-email-kan.liang@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The check for the maximum code is off-by-one; the current comparison of
a code that is INTEL_PT_ERR_MAX will cause the strlcpy to perform an out
of bounds array access on the intel_pt_err_msgs array.

Fix this with a >= comparison.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461524203-10224-1-git-send-email-colin.king@canonical.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Given that the 'val' parameter is ignored for FUTEX_LOCK_PI, get rid of
the bogus deadlock detection flag in the wrapper code and avoid the
extra argument, making it resemble its unlock counterpart. And if
nothing else, we already only pass 0 anyway.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1461208447-29328-1-git-send-email-dave@stgolabs.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The current assert check is checking an assignment, which will always be
true.  Instead, the assert should be checking if scale is equal to 0.122
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461419154-16918-1-git-send-email-colin.king@canonical.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: NEric Engestrom <eric.engestrom@imgtec.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461577678-29517-1-git-send-email-eric.engestrom@imgtec.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Turn current clean output:

  $ make clean
  rm -f arch/x86/include/generated/asm/syscalls_64.c
    CLEAN    libbpf
    CLEAN    libapi

into:

  $ make clean
    CLEAN    x86
    CLEAN    libapi
    CLEAN    libbpf
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: TJ <linux@iam.tj>
Link: http://lkml.kernel.org/r/1461615438-27894-1-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

While trying to use --call-graph lbr in 'perf trace', since we only are
interested in the callchain for userspace, up to the callchain, I found
that 'perf evlist' is not decoding the branch_sample_type field, fix it.

Before:

  # perf record --call-graph lbr usleep 1
  # perf evlist -v
  cycles:ppp: size: 112, { sample_period, sample_freq }: 4000,
  sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|BRANCH_STACK,
  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, branch_sample_type: 51201
                ^^^^^^^^^^^^^^^^^^^^^^^^^

After:

  # perf evlist -v
  cycles:ppp: size: 112, { sample_period, sample_freq }: 4000,
  sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|BRANCH_STACK,
  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, branch_sample_type: USER|CALL_STACK|NO_FLAGS|NO_CYCLES
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-hozai7974u0ulgx13k96fcaw@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To check deeply nested page fault callchains.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wuji34xx003kr88nmqt6jkgf@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-shj0fazntmskhjild5i6x73l@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>