linux-toradex.git/tools/perf/util/probe-finder.h, branch v3.0.2

perf probe: Add fastpath to do lookup by function name

2011-03-29T16:40:27+00:00

v3 -> v2:
- Make pubname_search_cb more generic
- Add fastpath to find_probes also

v2 -> v1:
- Don't compare file names with cu_find_realpath(...), instead, compare
  them with the name returned by dwarf_decl_file(sp_die)

The vmlinux file may have thousands of CUs.
We can lookup function name from .debug_pubnames section
to avoid the slow loop on CUs.

1. Improvement data for find_line_range

./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \
        -s /home/mlin/linux-2.6 \
        --line csum_partial_copy_to_user > tmp.log

before patch applied
=====================
       847,988,276 cycles

        0.355075856  seconds time elapsed

after patch applied
=====================
       206,102,622 cycles

        0.086883555  seconds time elapsed

2. Improvement data for find_probes

./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \
        -s /home/mlin/linux-2.6 \
        --vars csum_partial_copy_to_user > tmp.log

before patch applied
=====================
       848,490,844 cycles

        0.355307901  seconds time elapsed

after patch applied
=====================
       205,684,469 cycles

        0.086694010  seconds time elapsed

Acked-by: Masami Hiramatsu 
Cc: Ingo Molnar 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: linux-kernel 
LKML-Reference: <1301041668.14111.52.camel@minggr.sh.intel.com>
Signed-off-by: Lin Ming 
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove hardcoded include paths for elfutils

2010-11-19T18:38:04+00:00

This change removes the use of hardcoded absolute "/usr/include/elfutils" paths
from the perf build.  The problem with hardcoded paths is that it prevents them
from being overridden by $prefix or by -I in CFLAGS (e.g., for cross-compiling
purposes).

Instead, just include the "elfutils/" subdirectory as a relative path when
files are needed from that directory.

Tested by building perf:
- Cross-compiled for ARM on x86_64
- Built natively on x86_64
- Built on x86_64 with /usr/include/elfutils moved to another location
  and manually included in CFLAGS

Acked-by: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Masami Hiramatsu 
LKML-Reference: <1289945793-31441-1-git-send-email-rmorell@nvidia.com>
Signed-off-by: Robert Morell 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Add basic module support

2010-10-21T18:11:44+00:00

Add basic module probe support on perf probe. This introduces "--module
" option to perf probe for putting probes and showing lines and
variables in the given module.

Currently, this supports only probing on running modules.  Supporting off-line
module probing is the next step.

e.g.)
[show lines]
 # ./perf probe --module drm -L drm_vblank_info

      0  int drm_vblank_info(struct seq_file *m, void *data)
      1  {
                struct drm_info_node *node = (struct drm_info_node *) m->private
      3         struct drm_device *dev = node->minor->dev;
 ...
[show vars]
 # ./perf probe --module drm -V drm_vblank_info:3
Available variables at drm_vblank_info:3
        @
                (unknown_type)  data
                struct drm_info_node*   node
                struct seq_file*        m
[put a probe]
 # ./perf probe --module drm drm_vblank_info:3 node m
Add new event:
  probe:drm_vblank_info (on drm_vblank_info:3 with node m)

You can now use it on all perf tools, such as:

        perf record -e probe:drm_vblank_info -aR sleep 1
[list probes]
 # ./perf probe -l
probe:drm_vblank_info (on drm_vblank_info:3@drivers/gpu/drm/drm_info.c with ...

Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Frederic Weisbecker 
LKML-Reference: <20101021101341.3542.71638.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Show accessible global variables

2010-10-21T18:06:42+00:00

Add --externs for allowing --vars to show accessible global (externally
defined) variables from a given probe point too.

This will give you a hint which globals can be accessible from the probe point.

Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Frederic Weisbecker 
LKML-Reference: <20101021101335.3542.31003.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Show accessible local variables

2010-10-21T17:59:06+00:00

Add -V (--vars) option for listing accessible local variables at given probe
point. This will help finding which local variables are available for event
arguments.

e.g.)
 # perf probe -V call_timer_fn:23
 Available variables at call_timer_fn:23
         @
                 function_type*  fn
                 int     preempt_count
                 long unsigned int       data
                 struct list_head        work_list
                 struct list_head*       head
                 struct timer_list*      timer
                 struct tvec_base*       base

Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Frederic Weisbecker 
LKML-Reference: <20101021101323.3542.40282.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Rename common fields/functions from kprobe to probe.

2010-07-30T15:01:38+00:00

As a precursor for perf to support uprobes, rename fields/functions
that had kprobe in their name but can be shared across perf-kprobes
and perf-uprobes to probe.

Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Christoph Hellwig 
Cc: "Frank Ch. Eigler" 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Jim Keniston 
Cc: Linus Torvalds 
Cc: Mark Wielaard 
Cc: Mathieu Desnoyers 
Cc: Naren A Devaiah 
Cc: Oleg Nesterov 
Cc: "Paul E. McKenney" 
Cc: Peter Zijlstra 
Cc: Randy Dunlap 
Cc: Steven Rostedt 
LKML-Reference: <20100729141351.GG21723@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Don't compile CFI related code if elfutils is old

2010-05-18T01:13:51+00:00

Check elfutils version, and if it is old don't compile CFI analysis code. This
allows to compile perf with old elfutils.

Signed-off-by: Masami Hiramatsu 
Tested-by: Stephane Eranian 
Reported-by: Robert Richter 
Cc: Ingo Molnar 
LKML-Reference: <20100510171207.26029.97604.stgit@localhost6.localdomain6>
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Add --max-probes option

2010-04-26T18:35:20+00:00

Add --max-probes option to change the maximum limit of
findable probe points per event, since inlined function can be
expanded into thousands of probe points. Default value is 128.

Signed-off-by: Masami Hiramatsu 
Suggested-by: Arnaldo Carvalho de Melo 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Mike Galbraith 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
LKML-Reference: <20100421195640.24664.62984.stgit@localhost6.localdomain6>
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Support DW_OP_call_frame_cfa in debuginfo

2010-04-14T20:28:20+00:00

When building kernel without CONFIG_FRAME_POINTER, gcc uses
CFA (canonical frame address) for frame base. With this patch,
perf probe just gets CFI (call frame information) from debuginfo
and search corresponding CFA from the CFI. IOW, this allows
perf probe works correctly on the kernel without CONFIG_FRAME_POINTER.


 ./perf probe -fn sched_slice:12 lw.weight
  Fatal: DW_OP 156 is not supported.
              (^^^ DW_OP_call_frame_cfa)


./perf probe -fn sched_slice:12 lw.weight
Add new event:
  probe:sched_slice    (on sched_slice:12 with weight=lw.weight)

Cc: Ingo Molnar 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Mike Galbraith 
Cc: Frederic Weisbecker 
LKML-Reference: <20100412171728.3790.98217.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Reorganize some structs to save space

2010-04-08T14:34:26+00:00

Using 'pahole --packable' I found some structs that could be reorganized
to eliminate alignment holes, in some cases getting them to be cacheline
multiples.

[acme@doppio linux-2.6-tip]$ codiff perf.old ~/bin/perf
builtin-annotate.c:
  struct perf_session    |   -8
  struct perf_header     |   -8
 2 structs changed

builtin-diff.c:
  struct sample_data         |   -8
 1 struct changed
  diff__process_sample_event |   -8
 1 function changed, 8 bytes removed, diff: -8

builtin-sched.c:
  struct sched_atom      |   -8
 1 struct changed

builtin-timechart.c:
  struct per_pid         |   -8
 1 struct changed
  cmd_timechart          |  -16
 1 function changed, 16 bytes removed, diff: -16

builtin-probe.c:
  struct perf_probe_point |   -8
  struct perf_probe_event |   -8
 2 structs changed
  opt_add_probe_event     |   -3
 1 function changed, 3 bytes removed, diff: -3

util/probe-finder.c:
  struct probe_finder      |   -8
 1 struct changed
  find_kprobe_trace_events |  -16
 1 function changed, 16 bytes removed, diff: -16

/home/acme/bin/perf:
 4 functions changed, 43 bytes removed, diff: -43
[acme@doppio linux-2.6-tip]$

Cc: Frédéric Weisbecker 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo