Merge tag 'perf-core-for-mingo-4.11-20170215' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core clang fixes from Arnaldo Carvalho de Melo:

Changes to make tools/{perf,lib/{bpf,traceevent,api}} build with
CC=clang, to, for instance, take advantage of warnings (Arnaldo Carvalho de Melo):

- Conditionally request some warning options not available on clang

- Set the maximum optimization level to -O3 when using CC=clang, leave
  the previous setting of -O6 otherwise.

- Make it an error to pass a signed value to OPTION_UINTEGER, so that
  we can remove abs(unsigned int) calls in 'perf bench futex'.

- Make sure dprintf() is not defined before using that name in 'perf bench numa'

- Avoid using field after variable sized type, its a GNU extension, use
  equivalent code.

- Fix some bugs where some variables could be used unitialized,
  something not caught by gcc.

- Fix some spots where we were testing struct->array[] members against
  NULL, it will always evaluate to 'true'.

- Add missing parse_events_error() prototype in the bison file.

There are still one problem when trying to build the python support, but
this are the 'size' outputs for 'make -C tools/perf NO_LIBPYTHON' for
gcc and clang builds:

  DW_AT_producer: clang version 4.0.0 (http://llvm.org/git/clang.git f5be8ba13adc4ba1011a7ccd60c844bd60427c1c) (ht

  $ size ~/bin/perf
     text    data     bss     dec     hex     filename
  3447514  831320 23901696  28180530  1ae0032 /home/acme/bin/perf

  DW_AT_producer: GNU C99 6.3.1 20161221 (Red Hat 6.3.1-1) -mtune=generic -march=x86-64 -ggdb3 -O6 -std=gnu99
+-fno-omit-frame-pointer -funwind-tables -fstack-protector-all

  $ size ~/bin/perf
     text    data     bss     dec     hex     filename
  3671662  836480 23902752  28410894  1b1840e /home/acme/bin/perf
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

As pointed out by clang, we were not providing a prototype for a
function before using it:

  util/parse-events.y:699:6: error: conflicting types for 'parse_events_error'
  void parse_events_error(YYLTYPE *loc, void *data,
       ^
  /tmp/build/perf/util/parse-events-bison.c:2224:7: note: previous implicit declaration is here
        yyerror (&yylloc, _data, scanner, YY_("syntax error"));
        ^
  /tmp/build/perf/util/parse-events-bison.c:65:25: note: expanded from macro 'yyerror'
  #define yyerror         parse_events_error

  1 error generated.

One line fix it.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170215130605.GC4020@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The alias->unit field is an array, so to check that it is not set we
should see if it is an empty string, i.e. alias->unit[0], instead of
checking alias->unit != NULL, as this will _always_ evaluate to 'true'.

Pointed out by clang.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170214182435.GD4458@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In a few cases we were using 'enum map_type' and that triggered this
warning when using clang:

  util/session.c:1923:16: error: comparison of constant 2 with expression of type 'enum map_type' is always true
      [-Werror,-Wtautological-constant-out-of-range-compare]
        for (i = 0; i < MAP__NR_TYPES; ++i) {

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-i6uyo6bsopa2dghnx8qo7rri@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

So set it only for other compilers, allowing us to overcome yet another
build failure due to an inexistent clang -W option:

  error: unknown warning option '-Wno-override-init'; did you mean '-Wno-override-module'? [-Werror,-Wunknown-warning-option]

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-oaa1ici3j8nygp4pzl2oobh3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As this is a GNU extension and while harmless in this case, we can do
the same thing in a more clearer way by using a existing thread_map and
cpu_map constructors:

With this we avoid this while compiling with clang:

  util/evsel.c:1659:17: error: field 'map' with variable sized type 'struct cpu_map' not at the end of a struct or class is a GNU extension
        [-Werror,-Wgnu-variable-sized-type-not-at-end]
          struct cpu_map map;
                         ^
  util/evsel.c:1667:20: error: field 'map' with variable sized type 'struct thread_map' not at the end of a struct or class is a GNU extension
        [-Werror,-Wgnu-variable-sized-type-not-at-end]
          struct thread_map map;
                            ^
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-207juvrqjiar7uvas2s83v5i@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Genuine problem detected with clang, the warnings are spot on:

  util/probe-event.c:2079:7: error: variable 'map' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
                  if (addr) {
                      ^~~~
  util/probe-event.c:2094:6: note: uninitialized use occurs here
          if (map && !is_kprobe) {
              ^~~
  util/probe-event.c:2079:3: note: remove the 'if' if its condition is always true
                  if (addr) {
                  ^~~~~~~~~~
  util/probe-event.c:2075:8: error: variable 'map' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
                          if (kernel_get_symbol_address_by_name(tp->symbol,
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  util/probe-event.c:2094:6: note: uninitialized use occurs here
          if (map && !is_kprobe) {
              ^~~
  util/probe-event.c:2075:4: note: remove the 'if' if its condition is always false
                          if (kernel_get_symbol_address_by_name(tp->symbol,
                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  util/probe-event.c:2064:17: note: initialize the variable 'map' to silence this warning
          struct map *map;
                         ^
                          = NULL

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-m3501el55i10hctfbmi2qxzr@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As this is a GNU extension and while harmless in this case, we can do
the same thing in a more clearer way by using an existing thread_map
constructor.

With this we avoid this while compiling with clang:

  util/parse-events.c:2024:21: error: field 'map' with variable sized type 'struct thread_map' not at the end of a struct or class is a GNU extension
        [-Werror,-Wgnu-variable-sized-type-not-at-end]
                  struct thread_map map;
                                  ^
  1 error generated.

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-tqocbplnyyhpst6drgm2u4m3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As this is a GNU extension and while harmless in this case, we can do
the same thing in a more clearer way by using an existing thread_map
constructor.

With this we avoid this while compiling with clang:

  builtin-record.c:659:21: error: field 'map' with variable sized type 'struct thread_map' not at the end of a struct or class is a GNU extension
        [-Werror,-Wgnu-variable-sized-type-not-at-end]
                  struct thread_map map;
                                    ^
  1 error generated.

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-c9drclo52ezxmwa7qxklin2y@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

End result is the same, its an ABI, so the struct won't change, avoid
using a GNU extension, so that we can catch other cases that may be bugs.

Caught when building with clang:

  tests/parse-no-sample-id-all.c:53:20: error: field 'attr' with variable sized type 'struct attr_event' not at the end of a struct or class is a GNU extension
        [-Werror,-Wgnu-variable-sized-type-not-at-end]
          struct attr_event attr;
                            ^
  1 error generated.

Testing it:

  # perf test sample_id
  24: Parse with no sample_id_all bit set        : Ok
  #

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-e2vs1x771fc208uvxnwcf08b@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When building with clang we get this error:

  bench/numa.c:46:9: error: 'dprintf' macro redefined [-Werror,-Wmacro-redefined]
  #define dprintf(x...) do { if (g && g->p.show_details >= 1) printf(x); } while (0)
          ^
  /usr/include/bits/stdio2.h:145:12: note: previous definition is here
  #   define dprintf(fd, ...) \
             ^
    CC       /tmp/build/perf/tests/parse-no-sample-id-all.o
  1 error generated.

So, make sure it is undefined before using that name.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jakub Jelen <jjelen@redhat.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-f654o2svtrutamvxt7igwz74@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This reverts commit 60758d66.

Now that libsubcmd makes sure that OPT_UINTEGER options will not
return negative values, we can revert this patch while addressing
the problem it solved:

  # perf bench futex hash -t  -4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  # perf bench futex hash -t-4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  #

IMO it is more reasonable to flat out refuse to process a negative
number than to silently turn it into an absolute value.

This also helps in silencing clang's complaint about asking for an
absolute value of an unsigned integer:

  bench/futex-hash.c:133:10: error: taking the absolute value of unsigned type 'unsigned int' has no effect [-Werror,-Wabsolute-value]
          nsecs = futexbench_sanitize_numeric(nsecs);
                ^
  bench/futex.h:104:42: note: expanded from macro 'futexbench_sanitize_numeric'
  #define futexbench_sanitize_numeric(__n) abs((__n))
                                           ^
  bench/futex-hash.c:133:10: note: remove the call to 'abs' since unsigned values cannot be negative

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2kl68v22or31vw643m2exz8x@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Options marked OPTION_UINTEGER or OPTION_U64 clearly indicates that an
unsigned value is expected, so just error out when a negative value is
passed, instead of returning something undesired to the tool.

E.g.:

  # perf bench futex hash -t -4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2mdn8s2raatyhz7tamrsz22r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To avoid this when using clang:

  warning: optimization level '-O6' is not supported; using '-O3' instead

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-kaghp8ddvzdsg03putemcq96@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To allow building with clang, avoiding:

  error: unknown warning option '-Wstrict-aliasing=3'; did you mean '-Wstring-plus-int'? [-Werror,-Wunknown-warning-option]

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-xvthlvmhzfnt7jx73jgmaea1@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-core-for-mingo-4.11-20170213' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

New features:

 - Introduce the 'delta-abs' 'perf diff' compute method, that orders the
   histogram entries by the absolute value of the percentage delta for a
   function in two perf.data files, i.e. the functions that changed the
   most (increase or decrease in samples) comes first (Namhyung Kim)

User visible changes:

 - Improve message about tweaking the kernel.perf_event_paranoid setting,
   telling how to make the change permanent by editing /etc/sysctl.conf
   (Arnaldo Carvalho de Melo)

Infrastructure changes:

 - Introduce linux/compiler-gcc.h as a counterpart to the kernel's,
   initially containing the definition of __fallthrough, more to
   come (__maybe_unused, etc) (Arnaldo Carvalho de Melo)

 - Fixes for problems uncovered by building tools/perf with clang, such
   as always true tests of arrays against NULL and variables that sometimes
   were used without being initialized (Arnaldo Carvalho de Melo, Steven Rostedt)

 - Before loading a new ELF, clear global variables set by the
   samples/bpf loader (Mickaël Salaün)

 - Ignore already processed ELF sections in the samples/bpf
   loader (Mickaël Salaün)

 - Fix compile error in the scripting code with some perl5
   versions (Wang YanQing)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Before loading a new ELF, clean previous kernel version, license and
processed sections.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170208202744.16274-3-mic@digikod.netSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add a missing check for the map fixup loop.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170208202744.16274-2-mic@digikod.netSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Include unistd.h to define __NR_getuid and __NR_getsid.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170208202744.16274-4-mic@digikod.netSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As it will always evaluate to 'true', as reported by clang:

  util/map.c:390:36: error: address of array 'map->dso->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
          if (map && map->dso && (map->dso->name || map->dso->long_name)) {
                                  ~~~~~~~~~~^~~~ ~~
  util/map.c:393:22: error: address of array 'map->dso->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
                  else if (map->dso->name)
                     ~~  ~~~~~~~~~~^~~~

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-x8cu007cly40kfp8xnpi9kya@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It will always evaluate to 'true', as clang warns:

    CC       /tmp/build/perf/tests/perf-record.o
    CC       /tmp/build/perf/tests/evsel-roundtrip-name.o
  tests/perf-record.c:69:24: error: comparison of array 'argv' equal to a null pointer is always false [-Werror,-Wtautological-pointer-compare]
          if (evlist == NULL || argv == NULL) {
                                ^~~~    ~~~~
  1 error generated.

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-o4977g6p9b3peak9ct6ef48q@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As it is an array, so will always evaluate to 'true', as reported by
clang:

  builtin-sched.c:2070:19: error: address of array 'sym->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
                  if (sym && sym->name) {
                          ~~ ~~~~~^~~~
  1 warning generated.

So just ditch all those useless checks.

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-ydpm927col06paixb775jjx5@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When a tool can't open counters due to the kernel.perf_event_paranoit
sysctl setting, we inform how to tweak it to allow the operation to
succeed, in addition to that, suggest setting /etc/sysctl.conf to
make the setting permanent.
Suggested-by: Ingo Molnar <mingo@kernel.org>
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-4gwe99k4a6p12d4u8bbyttj2@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Detected with clang:

    CC       /tmp/build/perf/plugin_function.o
  plugin_function.c:145:6: warning: variable 'index' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
          if (parent && ftrace_indent->set)
              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  plugin_function.c:148:29: note: uninitialized use occurs here
          trace_seq_printf(s, "%*s", index*3, "");
                                     ^~~~~
  plugin_function.c:145:2: note: remove the 'if' if its condition is always true
          if (parent && ftrace_indent->set)
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  plugin_function.c:145:6: warning: variable 'index' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized]
          if (parent && ftrace_indent->set)
              ^~~~~~
  plugin_function.c:148:29: note: uninitialized use occurs here
          trace_seq_printf(s, "%*s", index*3, "");
                                     ^~~~~
  plugin_function.c:145:6: note: remove the '&&' if its condition is always true
          if (parent && ftrace_indent->set)
              ^~~~~~~~~
  plugin_function.c:133:11: note: initialize the variable 'index' to silence this warning
          int index;
                   ^
                    = 0
  2 warnings generated.
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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-b5wyjocel55gorl2jq2cbxrr@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

A undefined value was being used for the OLD_RING_BUFFER_TYPE_TIME_STAMP
case entry, as the 'length' variable was not being initialized, fix it.

Caught by the reporter when building tools/perf/ using clang, which emmitted
this warning:

  kbuffer-parse.c:312:7: warning: variable 'length' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
          case OLD_RINGBUF_TYPE_TIME_EXTEND:
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  kbuffer-parse.c:339:29: note: uninitialized use occurs here
          kbuf->next = kbuf->index + length;
                                   ^~~~~~
  kbuffer-parse.c:297:21: note: initialize the variable 'length' to silence this warning
          unsigned int length;
                             ^
                              = 0
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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/r/20170213121418.47f279e8@gandalf.local.homeSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Fix below compile error:

  CC       util/scripting-engines/trace-event-perl.o
  In file included from /usr/lib/perl5/5.22.2/i686-linux/CORE/perl.h:5673:0,
                   from util/scripting-engines/trace-event-perl.c:31:
  /usr/lib/perl5/5.22.2/i686-linux/CORE/inline.h: In function 'S__is_utf8_char_slow':
  /usr/lib/perl5/5.22.2/i686-linux/CORE/inline.h:270:5: error: nested extern declaration of 'Perl___notused' [-Werror=nested-externs]
          dTHX;   /* The function called below requires thread context */
			     ^
  cc1: all warnings being treated as errors

After digging perl5 repository, I find out that we will meet this
compile error with perl from v5.21.1 to v5.25.4
Signed-off-by: Wang YanQing <udknight@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170212024655.GA15997@udknightSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The "delta-abs" compute method will show most changed entries on top.
So users can easily see how much effect between the data.  Note that it
also changes the default of -o option to 1 in order to apply the compute
method.  To see original-style (sorted by baseline) use -o 0 option.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170210161856.18422-1-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The diff.compute config variable is to set the default compute method of
perf diff command (-c option).  Possible values 'delta' (default),
'delta-abs', 'ratio' and 'wdiff'.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: http://lkml.kernel.org/r/20170210073614.24584-4-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In many cases, I need to look at differences between two data so I often
used the -o option to sort the result base on the difference first.
It'd be nice to have a config option to set it by default.

The diff.order config option is to set the default value of -o/--order
option.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: http://lkml.kernel.org/r/20170210073614.24584-3-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The 'delta-abs' compute method is same as 'delta' but shows entries with
bigger absolute delta first instead of sorting numerically.  This is
only useful together with -o option.

Below is default output (-c delta):

  $ perf diff -o 1 -c delta | grep -v ^# | head
    42.22%   +4.97%  [kernel.kallsyms]  [k] cfb_imageblit
     0.62%   +1.23%  [kernel.kallsyms]  [k] mutex_lock
             +1.15%  [kernel.kallsyms]  [k] copy_user_generic_string
     2.40%   +0.95%  [kernel.kallsyms]  [k] bit_putcs
     0.31%   +0.79%  [kernel.kallsyms]  [k] link_path_walk
             +0.64%  [kernel.kallsyms]  [k] kmem_cache_alloc
     0.00%   +0.57%  [kernel.kallsyms]  [k] __rcu_read_unlock
             +0.45%  [kernel.kallsyms]  [k] alloc_set_pte
     0.16%   +0.45%  [kernel.kallsyms]  [k] menu_select
             +0.41%  ld-2.24.so         [.] do_lookup_x

Now with 'delta-abs' it shows entries have bigger delta value either
positive or negative.

  $ perf diff -o 1 -c delta-abs | grep -v ^# | head
    42.22%   +4.97%  [kernel.kallsyms]  [k] cfb_imageblit
    12.72%   -3.01%  [kernel.kallsyms]  [k] intel_idle
     9.72%   -1.31%  [unknown]          [.] 0x0000000000411343
     0.62%   +1.23%  [kernel.kallsyms]  [k] mutex_lock
     2.40%   +0.95%  [kernel.kallsyms]  [k] bit_putcs
     0.31%   +0.79%  [kernel.kallsyms]  [k] link_path_walk
     1.35%   -0.71%  [kernel.kallsyms]  [k] smp_call_function_single
     0.00%   +0.57%  [kernel.kallsyms]  [k] __rcu_read_unlock
     0.16%   +0.45%  [kernel.kallsyms]  [k] menu_select
     0.72%   -0.44%  [kernel.kallsyms]  [k] lookup_fast
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170210073614.24584-2-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To match the kernel headers structure, setting up things that are
specific to gcc or to some specific version of gcc.

It gets included by linux/compiler.h when gcc is the compiler being
used.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fabcqfq4asodq9t158hcs8t3@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add Kaby Lake mobile and desktop models for RAPL, CSTATE and UNCORE
matching Skylake.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: peterz@infradead.org
Cc: kan.liang@intel.com
Cc: bigeasy@linutronix.de
Cc: dave.hansen@linux.intel.com
Cc: piotr.luc@intel.com
Cc: davidcc@google.com
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1486755517-17812-1-git-send-email-srinivas.pandruvada@linux.intel.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

Pull x86 fixes from Ingo Molnar:
 "Last minute x86 fixes:

   - Fix a softlockup detector warning and long delays if using ptdump
     with KASAN enabled.

   - Two more TSC-adjust fixes for interesting firmware interactions.

   - Two commits to fix an AMD CPU topology enumeration bug that caused
     a measurable gaming performance regression"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/ptdump: Fix soft lockup in page table walker
  x86/tsc: Make the TSC ADJUST sanitizing work for tsc_reliable
  x86/tsc: Avoid the large time jump when sanitizing TSC ADJUST
  x86/CPU/AMD: Fix Zen SMT topology
  x86/CPU/AMD: Bring back Compute Unit ID

Pull timer fix from Ingo Molnar:
 "Fix a sporadic missed timer hw reprogramming bug that can result in
  random delays"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/nohz: Fix possible missing clock reprog after tick soft restart

Pull perf fixes from Ingo Molnar:
 "A kernel crash fix plus three tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix crash in perf_event_read()
  perf callchain: Reference count maps
  perf diff: Fix -o/--order option behavior (again)
  perf diff: Fix segfault on 'perf diff -o N' option

Pull lockdep fix from Ingo Molnar:
 "This fixes an ugly lockdep stack trace output regression. (But also
  affects other stacktrace users such as kmemleak, KASAN, etc)"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stacktrace, lockdep: Fix address, newline ugliness

Pull irq fixes from Ingo Molnar:
 "Two last minute ARM irqchip driver fixes"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mxs: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
  irqchip/keystone: Fix "scheduling while atomic" on rt

Pull btrfs fixes from Chris Mason:
 "This has two last minute fixes. The highest priority here is a
  regression fix for the decompression code, but we also fixed up a
  problem with the 32-bit compat ioctls.

  The decompression bug could hand back the wrong data on big reads when
  zlib was used. I have a larger cleanup to make the math here less
  error prone, but at this stage in the release Omar's patch is the best
  choice"

* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix btrfs_decompress_buf2page()
  btrfs: fix btrfs_compat_ioctl failures on non-compat ioctls