linux/tools/perf/Documentation/perf-annotate.txt
Arnaldo Carvalho de Melo be316409e9 perf annotate: Introduce --ignore-vmlinux command line option
This is already present in 'perf top', albeit undocumented (will fix),
and is useful to use /proc/kcore instead of vmlinux and then get what is
really in place, not what the kernel starts with, before alternatives,
ftrace .text patching, etc, see the differences:

  # perf annotate --stdio2 _raw_spin_lock_irqsave
  _raw_spin_lock_irqsave() /lib/modules/4.16.0-rc4/build/vmlinux
  Event: anon group { cycles, instructions }

    0.00   3.17      → callq  __fentry__
    0.00   7.94        push   %rbx
    7.69  36.51      → callq  __page_file_index
                       mov    %rax,%rbx
    7.69   3.17      → callq  *ffffffff82225cd0
                       xor    %eax,%eax
                       mov    $0x1,%edx
   80.77  49.21        lock   cmpxchg %edx,(%rdi)
                       test   %eax,%eax
                     ↓ jne    2b
    3.85   0.00        mov    %rbx,%rax
                       pop    %rbx
                     ← retq
                 2b:   mov    %eax,%esi
                     → callq  queued_spin_lock_slowpath
                       mov    %rbx,%rax
                       pop    %rbx
                     ← retq
  [root@jouet ~]# perf annotate --ignore-vmlinux --stdio2 _raw_spin_lock_irqsave
  _raw_spin_lock_irqsave() /proc/kcore
  Event: anon group { cycles, instructions }

    0.00   3.17        nop
    0.00   7.94        push   %rbx
    0.00  23.81        pushfq
    7.69  12.70        pop    %rax
                       nop
                       mov    %rax,%rbx
    7.69   3.17        cli
                       nop
                       xor    %eax,%eax
                       mov    $0x1,%edx
   80.77  49.21        lock   cmpxchg %edx,(%rdi)
                       test   %eax,%eax
                     ↓ jne    2b
    3.85   0.00        mov    %rbx,%rax
                       pop    %rbx
                     ← retq
                 2b:   mov    %eax,%esi
                     → callq  *ffffffff820e96b0
                       mov    %rbx,%rax
                       pop    %rbx
                     ← retq
  #

Diff of the output of those commands:

  # perf annotate --stdio2 _raw_spin_lock_irqsave > /tmp/vmlinux
  # perf annotate --ignore-vmlinux --stdio2 _raw_spin_lock_irqsave > /tmp/kcore
  # diff -y /tmp/vmlinux /tmp/kcore
  _raw_spin_lock_irqsave() vmlinux             | _raw_spin_lock_irqsave() /proc/kcore
  Event: anon group { cycles, instructions }     Event: anon group { cycles, instructions }

   0.00  3.17  → callq __fentry__              |  0.00  3.17     nop
   0.00  7.94    push  %rbx                       0.00  7.94     push  %rbx
   7.69 36.51  → callq __page_file_index       |  0.00 23.81     pushfq
                                               >  7.69 12.70     pop   %rax
                                               >                 nop
                 mov   %rax,%rbx                                 mov   %rax,%rbx
   7.69  3.17  → callq *ffffffff82225cd0       |  7.69  3.17     cli
                                               >                 nop
                 xor   %eax,%eax                                 xor   %eax,%eax
                 mov   $0x1,%edx                                 mov   $0x1,%edx
  80.77 49.21    lock  cmpxchg %edx,(%rdi)       80.77 49.21     lock  cmpxchg %edx,(%rdi)
                 test  %eax,%eax                                 test  %eax,%eax
               ↓ jne   2b                                      ↓ jne   2b
   3.85  0.00    mov   %rbx,%rax                  3.85  0.00     mov   %rbx,%rax
                 pop   %rbx                                      pop   %rbx
               ← retq                                          ← retq
            2b:  mov   %eax,%esi                            2b:  mov   %eax,%esi
               → callq queued_spin_lock_slowpath|              → callq *ffffffff820e96b0
                 mov   %rbx,%rax                                 mov   %rbx,%rax
                 pop   %rbx                                      pop   %rbx
               ← retq                                          ← retq
  #

This should be further streamlined by doing both annotations and
allowing the TUI to toggle initial/current, and show the patched
instructions in a slightly different color.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-wz8d269hxkcwaczr0r4rhyjg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-03-21 12:53:42 -03:00

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perf-annotate(1)
================
NAME
----
perf-annotate - Read perf.data (created by perf record) and display annotated code
SYNOPSIS
--------
[verse]
'perf annotate' [-i <file> | --input=file] [symbol_name]
DESCRIPTION
-----------
This command reads the input file and displays an annotated version of the
code. If the object file has debug symbols then the source code will be
displayed alongside assembly code.
If there is no debug info in the object, then annotated assembly is displayed.
OPTIONS
-------
-i::
--input=<file>::
Input file name. (default: perf.data unless stdin is a fifo)
-d::
--dsos=<dso[,dso...]>::
Only consider symbols in these dsos.
-s::
--symbol=<symbol>::
Symbol to annotate.
-f::
--force::
Don't do ownership validation.
-v::
--verbose::
Be more verbose. (Show symbol address, etc)
-q::
--quiet::
Do not show any message. (Suppress -v)
-n::
--show-nr-samples::
Show the number of samples for each symbol
-D::
--dump-raw-trace::
Dump raw trace in ASCII.
-k::
--vmlinux=<file>::
vmlinux pathname.
--ignore-vmlinux::
Ignore vmlinux files.
-m::
--modules::
Load module symbols. WARNING: use only with -k and LIVE kernel.
-l::
--print-line::
Print matching source lines (may be slow).
-P::
--full-paths::
Don't shorten the displayed pathnames.
--stdio:: Use the stdio interface.
--stdio2:: Use the stdio2 interface, non-interactive, uses the TUI formatting.
--stdio-color=<mode>::
'always', 'never' or 'auto', allowing configuring color output
via the command line, in addition to via "color.ui" .perfconfig.
Use '--stdio-color always' to generate color even when redirecting
to a pipe or file. Using just '--stdio-color' is equivalent to
using 'always'.
--tui:: Use the TUI interface. Use of --tui requires a tty, if one is not
present, as when piping to other commands, the stdio interface is
used. This interfaces starts by centering on the line with more
samples, TAB/UNTAB cycles through the lines with more samples.
--gtk:: Use the GTK interface.
-C::
--cpu=<cpu>:: Only report samples for the list of CPUs provided. Multiple CPUs can
be provided as a comma-separated list with no space: 0,1. Ranges of
CPUs are specified with -: 0-2. Default is to report samples on all
CPUs.
--asm-raw::
Show raw instruction encoding of assembly instructions.
--show-total-period:: Show a column with the sum of periods.
--source::
Interleave source code with assembly code. Enabled by default,
disable with --no-source.
--symfs=<directory>::
Look for files with symbols relative to this directory.
-M::
--disassembler-style=:: Set disassembler style for objdump.
--objdump=<path>::
Path to objdump binary.
--skip-missing::
Skip symbols that cannot be annotated.
--group::
Show event group information together
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-report[1]