There's no need to setup elide of sort_dso sort entry again
with symbol_conf.dso_list list.

The only difference were list names of memory mode data,
which does not make much sense to me.
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@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>
Link: http://lkml.kernel.org/r/1400858147-7155-2-git-send-email-jolsa@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Convert "==" into "=" in ui_browser__warning assignment.

Bug description: https://bugzilla.kernel.org/show_bug.cgi?id=76751Reported-by: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NDianfang Zhang <zhangdianfang@huawei.com>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jean Delvare <jdelvare@suse.de>
Link: http://lkml.kernel.org/r/20140530154709.GC1202@kernel.org
[ changed the changelog a bit ]
Signed-off-by: NJiri Olsa <jolsa@kernel.org>

SYSFS_PATH and PROC_PATH environment variables now let the user override
the detection of sysfs and proc locations for testing purposes.
Signed-off-by: NCody P Schafer <dev@codyps.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1401236684-10579-2-git-send-email-dev@codyps.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

This fixes lookups like "vi -t event_format"
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20140528081918.GA28567@linutronix.deSigned-off-by: NJiri Olsa <jolsa@kernel.org>

We were just showing "libperl: OFF", unlike other features where we
present the user with a message helping have a feature built in.

Fix it by adding the following message:

config/Makefile:450: Missing perl devel files. Disabling perl scripting support, consider installing perl-ExtUtils-Embed
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-t7yeud34ehimlfi6pklb29p7@git.kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

When the audit-libs devel package is not found at build time we disable
the 'trace' command, as we are not able to map syscall numbers to
strings, but then the message the user is presented is cryptic:

  [root@zoo linux]# trace ls
  perf: 'ls' is not a perf-command. See 'perf --help'.

Fix it by presenting a more helpful message:

  [root@zoo linux]# trace l
  trace command not available: missing audit-libs devel package at build time.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-uxeunqetd0sgxyibusapen9a@git.kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/core

Pull perf/core improvements and fixes from Jiri Olsa:

  * Add support to accumulate hist periods (Namhyung Kim)
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Now it adds a new testcase to verify --children option working
correctly.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-28-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

In various histogram test cases, fake symbols are used as raw numbers.
Define macros for each pid, map, symbols so that it can increase
readability somewhat.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-27-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

When reset_output_field() is called, also reset field/sort order to
NULL so that it can have the default values.  It's needed for testing.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
CC: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-26-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

With current output field change, GTK browser cannot display callchain
information correctly since it couldn't determine where the symbol
column is.  This is a problem - just for now I changed to use the last
column since it'll work for most cases.

Also it has a same problem of the percentage as stdio code.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-25-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

On stdio, there's a problem that it shows invalid values for
callchains in cumulated hist entries.  It's because it only cares
about the self period.  But with --children behavior, we always add
callchain info to the cumulated entries so it should use the value in
that case.

Before:

  # Children      Self  Command      Shared Object            Symbol
  # ........  ........  .......  .................  ................
  #
      61.22%     0.32%  swapper  [kernel.kallsyms]      [k] cpu_idle
                    |
                    --- cpu_idle
                       |
                       |--16530.76%-- start_secondary
                       |
                       |--2758.70%-- rest_init
                       |          start_kernel
                       |          x86_64_start_reservations
                       |          x86_64_start_kernel
                        --6837850969203030.00%-- [...]

After:

  # Children      Self  Command      Shared Object            Symbol
  # ........  ........  .......  .................  ................
  #
      61.22%     0.32%  swapper  [kernel.kallsyms]      [k] cpu_idle
                    |
                    --- cpu_idle
                       |
                       |--85.70%-- start_secondary
                       |
                        --14.30%-- rest_init
                                  start_kernel
                                  x86_64_start_reservations
                                  x86_64_start_kernel
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-24-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Now perf top and perf report will show children column by default if
it has callchain information.
Requested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Tested-by: NArun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-23-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Add top.children config option for setting default value of
callchain accumulation.  It affects the output only if one of
-g or --call-graph option is given as well.

A user can write .perfconfig file like below to enable accumulation
by default:

  $ cat ~/.perfconfig
  [top]
  children = true

And it can be disabled through command line:

  $ perf top --no-children
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-22-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The --children option is for showing accumulated overhead (period)
value as well as self overhead.  It should be used with one of -g or
--call-graph option.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-21-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Reuse hist_entry_iter__add() function to share the similar code with
perf report.  Note that it needs to be called with hists.lock so tweak
some internal functions not to deadlock or hold the lock too long.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Link: http://lkml.kernel.org/r/1401335910-16832-20-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The new ->add_entry_cb() will be called after an entry was added to
the histogram.  It's used for code sharing between perf report and
perf top.  Note that ops->add_*_entry() should set iter->he properly
in order to call the ->add_entry_cb.

Also pass @arg to the callback function.  It'll be used by perf top
later.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/87k393g999.fsf@sejong.aot.lge.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Depending on the configuration perf inserts/removes the Children
column in the output automatically.  But it might not be what user
wants if [s]he give --fields option explicitly.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-18-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Add report.children config option for setting default value of
callchain accumulation.  It affects the report output only if
perf.data contains callchain info.

A user can write .perfconfig file like below to enable accumulation
by default:

  $ cat ~/.perfconfig
  [report]
  children = true

And it can be disabled through command line:

  $ perf report --no-children
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-17-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The --children option is for showing accumulated overhead (period)
value as well as self overhead.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-16-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Sometimes it needs to disable some columns at runtime.  Add help
functions to support that.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-15-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

If -g cumulative option is given, it needs to show entries which don't
have self overhead.  So apply percent-limit to accumulated overhead
percentage in this case.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-14-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Print accumulated stat of a hist entry if requested.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-13-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Print accumulated stat of a hist entry if requested.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-12-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Print accumulated stat of a hist entry if requested.

To do that, add new HPP_PERCENT_ACC_FNS macro and generate a
perf_hpp_fmt using it.  The __hpp__sort_acc() function sorts entries
by accumulated period value.  When accumulated periods of two entries
are same (i.e. single path callchain) put the caller above since
accumulation tends to put callers on higher position for obvious
reason.

Also add "overhead_children" output field to be selected by user.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-11-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

When accumulating callchain entry, also save current snapshot of the
chain so that it can show the rest of the chain.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-10-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The callchain_cursor_snapshot() is for saving current status of the
callchain.  It'll be used to accumulate callchain information for each node.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-9-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

It is possble that a callchain has cycles or recursive calls.  In that
case it'll end up having entries more than 100% overhead in the
output.  In order to prevent such entries, cache each callchain node
and skip if same entry already cumulated.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-8-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The cpumode and level in struct addr_localtion was set for a sample
and but updated as cumulative callchains were added.  This led to have
non-matching symbol and cpumode in the output.

Update it accordingly based on the fact whether the map is a part of
the kernel or not.  This is a reverse of what thread__find_addr_map()
does.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-7-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Call __hists__add_entry() for each callchain node to get an
accumulated stat for an entry.  Introduce new cumulative_iter ops to
process them properly.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-6-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

To support callchain accumulation, @entry should be recognized if it's
accumulated or not when add_hist_entry() called.  The period of an
accumulated entry should be added to ->stat_acc but not ->stat. Add
@sample_self arg for that.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-5-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Maintain accumulated stat information in hist_entry->stat_acc if
symbol_conf.cumulate_callchain is set.  Fields in ->stat_acc have same
vaules initially, and will be updated as callchain is processed later.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-4-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

There're some duplicate code when adding hist entries.  They are
different in that some have branch info or mem info but generally do
same thing.  So introduce new struct hist_entry_iter and add callbacks
to customize each case in general way.

The new perf_evsel__add_entry() function will look like:

  iter->prepare_entry();
  iter->add_single_entry();

  while (iter->next_entry())
    iter->add_next_entry();

  iter->finish_entry();

This will help further work like the cumulative callchain patchset.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArun Sharma <asharma@fb.com>
Tested-by: NRodrigo Campos <rodrigo@sdfg.com.ar>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1401335910-16832-3-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

There're some duplicate code for counting number of samples.  Add
hists__inc_nr_samples() and reuse it.
Suggested-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1401335910-16832-2-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/core

Pull perf/core improvements and fixes from Jiri Olsa:

  * Android related fixes for pager and map dso resolving (Michael Lentine)

  * Add -F option for specifying output fields (Namhyung Kim)
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This patch automatically adjusts the path of MMAP records
associated with Android system libraries.

The Android system is organized with system libraries found in
/system/lib and user libraries in /data/app-lib. On the host system
(not running Android), system libraries can be found in the downloaded
NDK directory under ${NDK_ROOT}/platforms/${APP_PLATFORM}/arch-${ARCH}/usr/lib
and the user libraries are installed under libs/${APP_ABI} within
the apk build directory. This patch makes running the reporting
tools possible on the host system using the libraries from the NDK.
Signed-off-by: NMichael Lentine <mlentine@google.com>
Reviewed-by: NStephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1400579330-5043-3-git-send-email-eranian@google.com
[ fixed 'space required before the open parenthesis' checkpatch.pl errors ]
Signed-off-by: NJiri Olsa <jolsa@kernel.org>

This patch adds a fallback to cat for the pager. This is useful
on environments, such as Android, where less does not exist.
It is better to default to cat than to abort.
Signed-off-by: NMichael Lentine <mlentine@google.com>
Reviewed-by: NStephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1400579330-5043-2-git-send-email-eranian@google.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

With new output fields option, its internal implementation was changed
so add a new testcase to verify whether it breaks things.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1400480762-22852-21-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Those print helper functions can be reused by later hist test cases so
factor them out to a common location.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1400480762-22852-20-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The reset_output_field() function is for clearing output field
settings and will be used for test code in later patch.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1400480762-22852-19-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>