linux-toradex.git/tools/perf/util/Build, branch v4.10

perf clang: Add builtin clang support ant test case

2016-12-05T18:51:43+00:00

Add basic clang support in clang.cpp and test__clang() testcase. The
first testcase checks if builtin clang is able to generate LLVM IR.

tests/clang.c is a proxy. Real testcase resides in
utils/c++/clang-test.cpp in c++ and exports C interface to perf test
subsystem.

Test result:

   $ perf test -v clang
   51: builtin clang support                               :
   51.1: Test builtin clang compile C source to IR              :
   --- start ---
   test child forked, pid 13215
   test child finished with 0
   ---- end ----
   Test builtin clang support subtest 0: Ok

Committer note:

Make sure you've enabled CLANG and LLVM builtin support by setting
the LIBCLANGLLVM variable on the make command line, e.g.:

  make LIBCLANGLLVM=1 O=/tmp/build/perf -C tools/perf install-bin

Otherwise you'll get this when trying to do the 'perf test' call above:

  # perf test clang
  51: builtin clang support                      : Skip (not compiled in)
  #

Signed-off-by: Wang Nan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Joe Stringer 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-11-wangnan0@huawei.com
[ Removed "Test" from descriptions, redundant and already removed from all the other entries ]
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add time-based utility functions

2016-12-01T16:02:32+00:00

Add function to parse a user time string of the form ,
where start and stop are time in sec.nsec format. Both start and stop
times are optional.

Add function to determine if a sample time is within a given time
time window of interest.

Signed-off-by: David Ahern 
Acked-by: Namhyung Kim 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1480439746-42695-2-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Introduce perf hooks

2016-11-29T15:13:27+00:00

Perf hooks allow hooking user code at perf events. They can be used for
manipulation of BPF maps, taking snapshot and reporting results. In this
patch two perf hook points are introduced: record_start and record_end.

To avoid buggy user actions, a SIGSEGV signal handler is introduced into
'perf record'. It turns off perf hook if it causes a segfault and report
an error to help debugging.

A test case for perf hook is introduced.

Test result:
  $ ./buildperf/perf test -v hook
  50: Test perf hooks                                          :
  --- start ---
  test child forked, pid 10311
  SIGSEGV is observed as expected, try to recover.
  Fatal error (SEGFAULT) in perf hook 'test'
  test child finished with 0
  ---- end ----
  Test perf hooks: Ok

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Joe Stringer 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-5-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf jit: Enable jitdump support without dwarf

2016-10-24T14:07:37+00:00

This patch modifies the build dependencies on the jitdump support in
perf. As it stands jitdump was wrongfully made dependent 100% on using
DWARF. However, the dwarf dependency, only exist if generating the
source line table in genelf_debug.c. The rest of the support does not
need DWARF.

This patch removes the dependency on DWARF for the entire jitdump
support. It keeps it only for the genelf_debug.c support.

Signed-off-by: Maciej Debski 
Reviewed-by: Stephane Eranian 
Cc: Anton Blanchard 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1476356383-30100-3-git-send-email-eranian@google.com
Fixes: e12b202f8fb9 ("perf jitdump: Build only on supported archs")
[ Make it build only if NO_LIBELF isn't defined, as jitdump.o will only be built in that case ]
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Push configuration down to PMU driver

2016-09-22T15:19:41+00:00

This patch adds a PMU callback and the required mechanic so that drivers
can process the command line configuration elements found in
evsel::config_terms.

Signed-off-by: Mathieu Poirier 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-6-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Add branch stack / basic block

2016-09-08T16:44:03+00:00

I wanted to know the hottest path through a function and figured the
branch-stack (LBR) information should be able to help out with that.

The below uses the branch-stack to create basic blocks and generate
statistics from them.

        from    to              branch_i
        * ----> *
                |
                | block
                v
                * ----> *
                from    to      branch_i+1

The blocks are broken down into non-overlapping ranges, while tracking
if the start of each range is an entry point and/or the end of a range
is a branch.

Each block iterates all ranges it covers (while splitting where required
to exactly match the block) and increments the 'coverage' count.

For the range including the branch we increment the taken counter, as
well as the pred counter if flags.predicted.

Using these number we can find if an instruction:

 - had coverage; given by:

        br->coverage / br->sym->max_coverage

   This metric ensures each symbol has a 100% spot, which reflects the
   observation that each symbol must have a most covered/hottest
   block.

 - is a branch target: br->is_target && br->start == add

 - for targets, how much of a branch's coverages comes from it:

	target->entry / branch->coverage

 - is a branch: br->is_branch && br->end == addr

 - for branches, how often it was taken:

        br->taken / br->coverage

   after all, all execution that didn't take the branch would have
   incremented the coverage and continued onward to a later branch.

 - for branches, how often it was predicted:

        br->pred / br->taken

The coverage percentage is used to color the address and asm sections;
for low (<1%) coverage we use NORMAL (uncolored), indicating that these
instructions are not 'important'. For high coverage (>75%) we color the
address RED.

For each branch, we add an asm comment after the instruction with
information on how often it was taken and predicted.

Output looks like (sans color, which does loose a lot of the
information :/)

$ perf record --branch-filter u,any -e cycles:p ./branches 27
$ perf annotate branches

 Percent |	Source code & Disassembly of branches for cycles:pu (217 samples)
---------------------------------------------------------------------------------
         :	branches():
    0.00 :	  40057a:       push   %rbp
    0.00 :	  40057b:       mov    %rsp,%rbp
    0.00 :	  40057e:       sub    $0x20,%rsp
    0.00 :	  400582:       mov    %rdi,-0x18(%rbp)
    0.00 :	  400586:       mov    %rsi,-0x20(%rbp)
    0.00 :	  40058a:       mov    -0x18(%rbp),%rax
    0.00 :	  40058e:       mov    %rax,-0x10(%rbp)
    0.00 :	  400592:       movq   $0x0,-0x8(%rbp)
    0.00 :	  40059a:       jmpq   400656 
    1.84 :	  40059f:       mov    -0x10(%rbp),%rax	# +100.00%
    3.23 :	  4005a3:       and    $0x1,%eax
    1.84 :	  4005a6:       test   %rax,%rax
    0.00 :	  4005a9:       je     4005bf 	# -54.50% (p:42.00%)
    0.46 :	  4005ab:       mov    0x200bbe(%rip),%rax        # 601170 
   12.90 :	  4005b2:       add    $0x1,%rax
    2.30 :	  4005b6:       mov    %rax,0x200bb3(%rip)        # 601170 
    0.46 :	  4005bd:       jmp    4005d1 	# -100.00% (p:100.00%)
    0.92 :	  4005bf:       mov    0x200baa(%rip),%rax        # 601170 	# +49.54%
   13.82 :	  4005c6:       sub    $0x1,%rax
    0.46 :	  4005ca:       mov    %rax,0x200b9f(%rip)        # 601170 
    2.30 :	  4005d1:       mov    -0x10(%rbp),%rax	# +50.46%
    0.46 :	  4005d5:       mov    %rax,%rdi
    0.46 :	  4005d8:       callq  400526 	# -100.00% (p:100.00%)
    0.00 :	  4005dd:       mov    %rax,-0x10(%rbp)	# +100.00%
    0.92 :	  4005e1:       mov    -0x18(%rbp),%rax
    0.00 :	  4005e5:       and    $0x1,%eax
    0.00 :	  4005e8:       test   %rax,%rax
    0.00 :	  4005eb:       je     4005ff 	# -100.00% (p:100.00%)
    0.00 :	  4005ed:       mov    0x200b7c(%rip),%rax        # 601170 
    0.00 :	  4005f4:       shr    $0x2,%rax
    0.00 :	  4005f8:       mov    %rax,0x200b71(%rip)        # 601170 
    0.00 :	  4005ff:       mov    -0x10(%rbp),%rax	# +100.00%
    7.37 :	  400603:       and    $0x1,%eax
    3.69 :	  400606:       test   %rax,%rax
    0.00 :	  400609:       jne    400612 	# -59.25% (p:42.99%)
    1.84 :	  40060b:       mov    $0x1,%eax
   14.29 :	  400610:       jmp    400617 	# -100.00% (p:100.00%)
    1.38 :	  400612:       mov    $0x0,%eax	# +57.65%
   10.14 :	  400617:       test   %al,%al	# +42.35%
    0.00 :	  400619:       je     40062f 	# -57.65% (p:100.00%)
    0.46 :	  40061b:       mov    0x200b4e(%rip),%rax        # 601170 
    2.76 :	  400622:       sub    $0x1,%rax
    0.00 :	  400626:       mov    %rax,0x200b43(%rip)        # 601170 
    0.46 :	  40062d:       jmp    400641 	# -100.00% (p:100.00%)
    0.92 :	  40062f:       mov    0x200b3a(%rip),%rax        # 601170 	# +56.13%
    2.30 :	  400636:       add    $0x1,%rax
    0.92 :	  40063a:       mov    %rax,0x200b2f(%rip)        # 601170 
    0.92 :	  400641:       mov    -0x10(%rbp),%rax	# +43.87%
    2.30 :	  400645:       mov    %rax,%rdi
    0.00 :	  400648:       callq  400526 	# -100.00% (p:100.00%)
    0.00 :	  40064d:       mov    %rax,-0x10(%rbp)	# +100.00%
    1.84 :	  400651:       addq   $0x1,-0x8(%rbp)
    0.92 :	  400656:       mov    -0x8(%rbp),%rax
    5.07 :	  40065a:       cmp    -0x20(%rbp),%rax
    0.00 :	  40065e:       jb     40059f 	# -100.00% (p:100.00%)
    0.00 :	  400664:       nop
    0.00 :	  400665:       leaveq
    0.00 :	  400666:       retq

(Note: the --branch-filter u,any was used to avoid spurious target and
branch points due to interrupts/faults, they show up as very small -/+
annotations on 'weird' locations)

Committer note:

Please take a look at:

  http://vger.kernel.org/~acme/perf/annotate_basic_blocks.png

To see the colors.

Signed-off-by: Peter Zijlstra (Intel) 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Anshuman Khandual 
Cc: David Carrillo-Cisneros 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Linus Torvalds 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
[ Moved sym->max_coverage to 'struct annotate', aka symbol__annotate(sym) ]
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Support probing on offline cross-arch binary

2016-09-01T15:41:09+00:00

Support probing on offline cross-architecture binary by adding getting
the target machine arch from ELF and choose correct register string for
the machine.

Here is an example:
  -----
  $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
  p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
  -----

Here, we can get probe/do_sys_open from above and append it to to the target
machine's tracing/kprobe_events file in the tracefs mountput, usually
/sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events).

Signed-off-by: Masami Hiramatsu 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox
[ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ]
Signed-off-by: Arnaldo Carvalho de Melo

tools lib api: Add str_error_c to libapi

2016-07-27T20:16:43+00:00

Because it uses that function, which would lead every tool using it
to need to link against tools/lib/str_error_r.o.

This fixes building tools/vm/, that links with libapi.

Reported-by: Arjan van de Ven 
Reported-by: Randy Dunlap 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Fixes: b31e3e3316a7 ("tools lib api fs: Use str_error_r()")
Link: http://lkml.kernel.org/n/tip-aedt3qzibhnhaov2j4caqi61@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Add Rust demangling

2016-07-12T19:12:38+00:00

Rust demangling is another step after bfd demangling. Add a diagnosis to
identify mangled Rust symbols based on the hash that the Rust mangler appends
as the last path component, as well as other characteristics.  Add a demangler
to reconstruct the original symbol.

Committer notes:

How I tested it:

Enabled COPR on Fedora 24 and then installed the 'rust-binary' package,
with it:

  $ cat src/main.rs
  fn main() {
      println!("Hello, world!");
  }
  $ cat Cargo.toml
  [package]

  name = "hello_world"
  version = "0.0.1"
  authors = [ "Arnaldo Carvalho de Melo " ]

  $ perf record cargo bench
   Compiling hello_world v0.0.1 (file:///home/acme/projects/hello_world)
     Running target/release/hello_world-d4b9dab4b2a47d75

  running 0 tests

  test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured

  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.096 MB perf.data (1457 samples) ]
  $

Before this patch:

  $ perf report --stdio --dsos librbml-e8edd0fd.so
  # dso: librbml-e8edd0fd.so
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'cycles:u'
  # Event count (approx.): 979599126
  #
  # Overhead  Command  Symbol
  # ........  .......  .............................................................................................................
  #
       1.78%  rustc    [.] rbml::reader::maybe_get_doc::hb9d387df6024b15b
       1.50%  rustc    [.] _$LT$reader..DocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::hd9af9e60d79a35c8
       1.20%  rustc    [.] rbml::reader::doc_at::hc88107fba445af31
       0.46%  rustc    [.] _$LT$reader..TaggedDocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::h0cb40e696e4bb489
       0.35%  rustc    [.] rbml::reader::Decoder::_next_int::h66eef7825a398bc3
       0.29%  rustc    [.] rbml::reader::Decoder::_next_sub::h8e5266005580b836
       0.15%  rustc    [.] rbml::reader::get_doc::h094521c645459139
       0.14%  rustc    [.] _$LT$reader..Decoder$LT$$u27$doc$GT$$u20$as$u20$serialize..Decoder$GT$::read_u32::h0acea2fff9669327
       0.07%  rustc    [.] rbml::reader::Decoder::next_doc::h6714d469c9dfaf91
       0.07%  rustc    [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt
       0.06%  rustc    [.] _fini
  $

After:

  $ perf report --stdio --dsos librbml-e8edd0fd.so
  # dso: librbml-e8edd0fd.so
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'cycles:u'
  # Event count (approx.): 979599126
  #
  # Overhead  Command  Symbol
  # ........  .......  .................................................................
  #
     1.78%  rustc    [.] rbml::reader::maybe_get_doc
     1.50%  rustc    [.]  as std::iter::Iterator>::next
     1.20%  rustc    [.] rbml::reader::doc_at
     0.46%  rustc    [.]  as std::iter::Iterator>::next
     0.35%  rustc    [.] rbml::reader::Decoder::_next_int
     0.29%  rustc    [.] rbml::reader::Decoder::_next_sub
     0.15%  rustc    [.] rbml::reader::get_doc
     0.14%  rustc    [.]  as serialize::Decoder>::read_u32
     0.07%  rustc    [.] rbml::reader::Decoder::next_doc
     0.07%  rustc    [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt
     0.06%  rustc    [.] _fini
  $

Signed-off-by: David Tolnay 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/5780B7FA.3030602@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Uninline scnprintf() and vscnprint()

2016-07-12T18:20:24+00:00

They were in tools/include/linux/kernel.h, requiring that it in turn
included stdio.h, which is way too heavy.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Josh Poimboeuf 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-855h8olnkot9v0dajuee1lo3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo