linux-stable.git/tools/perf/util/annotate.c, branch v6.8.2

perf annotate: Add --insn-stat option for debugging

2023-12-24T01:40:17+00:00

This is for a debugging purpose.  It'd be useful to see per-instrucion
level success/failure stats.

  $ perf annotate --data-type --insn-stat
  Annotate Instruction stats
  total 264, ok 143 (54.2%), bad 121 (45.8%)

    Name      :  Good   Bad
  -----------------------------------------------------------
    movq      :    45    31
    movl      :    22    11
    popq      :     0    19
    cmpl      :    16     3
    addq      :     8     7
    cmpq      :    11     3
    cmpxchgl  :     3     7
    cmpxchgq  :     8     0
    incl      :     3     3
    movzbl    :     4     2
    incq      :     4     2
    decl      :     6     0
    ...

Committer notes:

So these are about being able to find the type for accesses from these
instructions, we should improve the naming, but it is for debugging, we
can improve this later:

  @@ -3726,6 +3759,10 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
                          continue;

                  mem_type = find_data_type(ms, ip, op_loc->reg, op_loc->offset);
  +               if (mem_type)
  +                       istat->good++;
  +               else
  +                       istat->bad++;

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-18-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Add --type-stat option for debugging

2023-12-24T01:40:13+00:00

The --type-stat option is to be used with --data-type and to print
detailed failure reasons for the data type annotation.

  $ perf annotate --data-type --type-stat
  Annotate data type stats:
  total 294, ok 116 (39.5%), bad 178 (60.5%)
  -----------------------------------------------------------
          30 : no_sym
          40 : no_insn_ops
          33 : no_mem_ops
          63 : no_var
           4 : no_typeinfo
           8 : bad_offset

Signed-off-by: Namhyung Kim 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-17-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Add --data-type option

2023-12-24T01:39:43+00:00

Support data type annotation with new --data-type option.  It internally
uses type sort key to collect sample histogram for the type and display
every members like below.

  $ perf annotate --data-type
  ...
  Annotate type: 'struct cfs_rq' in [kernel.kallsyms] (13 samples):
  ============================================================================
      samples     offset       size  field
           13          0        640  struct cfs_rq         {
            2          0         16      struct load_weight       load {
            2          0          8          unsigned long        weight;
            0          8          4          u32  inv_weight;
                                         };
            0         16          8      unsigned long    runnable_weight;
            0         24          4      unsigned int     nr_running;
            1         28          4      unsigned int     h_nr_running;
  ...

For simplicity it prints the number of samples per field for now.
But it should be easy to show the overhead percentage instead.

The number at the outer struct is a sum of the numbers of the inner
members.  For example, struct cfs_rq got total 13 samples, and 2 came
from the load (struct load_weight) and 1 from h_nr_running.  Similarly,
the struct load_weight got total 2 samples and they all came from the
weight field.

I've added two new flags in the symbol_conf for this.  The
annotate_data_member is to get the members of the type.  This is also
needed for perf report with typeoff sort key.  The annotate_data_sample
is to update sample stats for each offset and used only in annotate.

Currently it only support stdio output mode, TUI support can be added
later.

Committer testing:

With the perf.data from the previous csets, a very simple, short
duration one:

  # perf annotate --data-type
  Annotate type: 'struct list_head' in [kernel.kallsyms] (1 samples):
  ============================================================================
      samples     offset       size  field
            1          0         16  struct list_head      {
            0          0          8      struct list_head*        next;
            1          8          8      struct list_head*        prev;
                                     };

  Annotate type: 'char' in [kernel.kallsyms] (1 samples):
  ============================================================================
      samples     offset       size  field
            1          0          1  char ;

  #

Signed-off-by: Namhyung Kim 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-15-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Add 'typeoff' sort key

2023-12-24T01:39:42+00:00

The typeoff sort key shows the data type name, offset and the name of
the field.  This is useful to see which field in the struct is accessed
most frequently.

  $ perf report -s type,typeoff --hierarchy --stdio
  ...
  #     Overhead  Data Type / Data Type Offset
  # ............  ............................
  #
  ...
        1.23%     struct cfs_rq
           0.19%    struct cfs_rq +404 (throttle_count)
           0.19%    struct cfs_rq +0 (load.weight)
           0.19%    struct cfs_rq +336 (leaf_cfs_rq_list.next)
           0.09%    struct cfs_rq +272 (propagate)
           0.09%    struct cfs_rq +196 (removed.nr)
           0.09%    struct cfs_rq +80 (curr)
           0.09%    struct cfs_rq +544 (lt_b_children_throttled)
           0.06%    struct cfs_rq +320 (rq)

Committer testing:

Again with the perf.data from the previous csets:

  # perf report --stdio -s type,typeoff
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 4  of event 'cpu_atom/mem-loads,ldlat=30/P'
  # Event count (approx.): 7
  #
  # Overhead  Data Type  Data Type Offset
  # ........  .........  ................
  #
      42.86%  struct list_head  struct list_head +8 (prev)
      42.86%  (unknown)  (unknown) +0 (no field)
      14.29%  char       char +0 (no field)

  #
  # (Tip: To see callchains in a more compact form: perf report -g folded)
  #
  # perf report --stdio -s dso,type,typeoff
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 4  of event 'cpu_atom/mem-loads,ldlat=30/P'
  # Event count (approx.): 7
  #
  # Overhead  Shared Object         Data Type  Data Type Offset
  # ........  ....................  .........  ................
  #
      42.86%  [kernel.kallsyms]     struct list_head  struct list_head +8 (prev)
      28.57%  libc.so.6             (unknown)  (unknown) +0 (no field)
      14.29%  [kernel.kallsyms]     char       char +0 (no field)
      14.29%  ld-linux-x86-64.so.2  (unknown)  (unknown) +0 (no field)

  #
  # (Tip: If you have debuginfo enabled, try: perf report -s sym,srcline)
  #
  #

Signed-off-by: Namhyung Kim 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-13-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate-data: Update sample histogram for type

2023-12-24T01:39:42+00:00

The annotated_data_type__update_samples() to get histogram for data type
access.

It'll be called by perf annotate to show which fields in the data type
are accessed frequently.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Implement hist_entry__get_data_type()

2023-12-24T01:39:42+00:00

It's the function to find out the type info from the given sample data
and will be called from the hist_entry sort logic when 'type' sort key
is used.

It first calls objdump to disassemble the instructions and figure out
information about memory access at the location.  Maybe we can do it
better by analyzing the instruction directly, but I'll leave it for
later work.

The memory access is determined by checking instruction operands to
have "(" and then extract register name and offset.  It'll return NULL
if no data type is found.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Add annotate_get_insn_location()

2023-12-24T01:39:42+00:00

The annotate_get_insn_location() is to get the detailed information of
instruction locations like registers and offset.  It has source and
target operands locations in an array.  Each operand can have a register
and an offset.  The offset is meaningful when mem_ref flag is set.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Factor out evsel__get_arch()

2023-12-24T01:39:42+00:00

The evsel__get_arch() is to get architecture info from the environment.

It'll be used by other places later so let's factor it out.

Also add arch__is() to check the arch info by name.

Committer notes:

"get" is usually associated with refcounting, so we better rename this
at some point to a better name.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Get rid of local annotation options

2023-12-07T20:18:50+00:00

It doesn't need the option in the struct annotation which is allocated
for each symbol.  It can directly use the global options and save 8
bytes per symbol.

Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20231128175441.721579-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Remove remaining usages of local annotation options

2023-12-07T20:18:37+00:00

So that it can get rid of the unused data.

Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20231128175441.721579-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo