[RFC/PATCHSET 0/6] perf tools: Support dynamic sort keys for tracepoints (v1)

[Namhyung Kim <namhyung@kernel.org>]

Hello,

This is an attempt to improve perf to deal with tracepoint events
better.  The perf tools can handle tracepoint events but perf report
on them is less useful since they're always sampled in a fixed
location and not provide event specific info.  We can use perf script
but I always wishes there's more convenient way to see the result.

I suggest dynamic sort keys created for each event.field on demand.
Consider following example:

  # Overhead  Command          Shared Object     Symbol
  # ........  ...............  ................  ..............
  #
      47.22%  swapper          [kernel.vmlinux]  [k] __schedule
      21.67%  transmission-gt  [kernel.vmlinux]  [k] __schedule
       8.23%  netctl-auto      [kernel.vmlinux]  [k] __schedule
       5.53%  kworker/0:1H     [kernel.vmlinux]  [k] __schedule
       1.98%  Xephyr           [kernel.vmlinux]  [k] __schedule
       1.33%  irq/33-iwlwifi   [kernel.vmlinux]  [k] __schedule
       1.17%  wpa_cli          [kernel.vmlinux]  [k] __schedule
       1.13%  rcu_preempt      [kernel.vmlinux]  [k] __schedule
       0.85%  ksoftirqd/0      [kernel.vmlinux]  [k] __schedule
       0.77%  Timer            [kernel.vmlinux]  [k] __schedule
  ...

Currently perf report only shows this but important info is on the
event fields, that is:

  # sudo cat /sys/kernel/debug/tracing/events/sched/sched_switch/format
  name: sched_switch
  ID: 268
  format:
    field:unsigned short common_type;         offset:0; size:2; signed:0;
    field:unsigned char common_flags;         offset:2; size:1; signed:0;
    field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
    field:int common_pid;                     offset:4; size:4; signed:1;

    field:char prev_comm[16]; offset:8;  size:16; signed:1;
    field:pid_t prev_pid;     offset:24; size:4;  signed:1;
    field:int prev_prio;      offset:28; size:4;  signed:1;
    field:long prev_state;    offset:32; size:8;  signed:1;
    field:char next_comm[16]; offset:40; size:16; signed:1;
    field:pid_t next_pid;     offset:56; size:4;  signed:1;
    field:int next_prio;      offset:60; size:4;  signed:1;

  print fmt: "prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==>
              next_comm=%s next_pid=%d next_prio=%d",
    REC->prev_comm, REC->prev_pid, REC->prev_prio,
    REC->prev_state & (2048-1) ? __print_flags(REC->prev_state & (2048-1),
    "|", { 1, "S"} , { 2, "D" }, { 4, "T" }, { 8, "t" }, { 16, "Z" }, { 32, "X" },
    { 64, "x" }, { 128, "K"}, { 256, "W" }, { 512, "P" }, { 1024, "N" }) : "R",
    REC->prev_state & 2048 ? "+" : "", REC->next_comm, REC->next_pid, REC->next_prio

With dynamic sort keys, you can use <event.field> as a sort key.  Those
dynamic keys are checked and created on demand.  For instance, below is
to sort by next_pid field on the same data file.

  $ perf report -s comm,sched:sched_switch.next_pid --stdio
  ...
  # Overhead  Command            next_pid
  # ........  ...............  ..........
  #
      21.23%  transmission-gt           0
      20.86%  swapper               17773
       6.62%  netctl-auto               0
       5.25%  swapper                 109
       5.21%  kworker/0:1H              0
       1.98%  Xephyr                    0
       1.98%  swapper                6524
       1.98%  swapper               27478
       1.37%  swapper               27476
       1.17%  swapper                 233

Multiple dynamic sort keys are also supported:

  $ perf report -s comm,sched:sched_switch.next_pid,sched:sched_switch.next_comm --stdio
  ...
  # Overhead  Command            next_pid         next_comm
  # ........  ...............  ..........  ................
  #
      20.86%  swapper               17773   transmission-gt
       9.64%  transmission-gt           0         swapper/0
       9.16%  transmission-gt           0         swapper/2
       5.25%  swapper                 109      kworker/0:1H
       5.21%  kworker/0:1H              0         swapper/0
       2.14%  netctl-auto               0         swapper/2
       1.98%  netctl-auto               0         swapper/0
       1.98%  swapper                6524            Xephyr
       1.98%  swapper               27478       netctl-auto
       1.78%  transmission-gt           0         swapper/3
       1.53%  Xephyr                    0         swapper/0
       1.29%  netctl-auto               0         swapper/1
       1.29%  swapper               27476       netctl-auto
       1.21%  netctl-auto               0         swapper/3
       1.17%  swapper                 233    irq/33-iwlwifi

Note that pid 0 exists for each cpu so have comm of 'swapper/N'.

This is available on 'perf/dynamic-sort-v1' branch in my tree

  git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git

Any comments are welcome, thanks!
Namhyung


Namhyung Kim (6):
  perf hist: Pass struct sample to __hists__add_entry()
  perf hist: Save raw_data/size for tracepoint events
  tools lib traceevent: Factor out and export print_event_field()
  perf tools: Pass evlist to setup_sorting()
  perf tools: Add dynamic sort key for tracepoint events
  perf tools: Try to show pretty printed output for dynamic sort keys

 tools/lib/traceevent/event-parse.c | 124 ++++++++-------
 tools/lib/traceevent/event-parse.h |   2 +
 tools/perf/builtin-annotate.c      |   9 +-
 tools/perf/builtin-diff.c          |  13 +-
 tools/perf/builtin-report.c        |   2 +-
 tools/perf/builtin-top.c           |  14 +-
 tools/perf/tests/hists_cumulate.c  |   8 +-
 tools/perf/tests/hists_filter.c    |   2 +-
 tools/perf/tests/hists_link.c      |   8 +-
 tools/perf/tests/hists_output.c    |  10 +-
 tools/perf/util/hist.c             |  33 ++--
 tools/perf/util/hist.h             |   4 +-
 tools/perf/util/sort.c             | 309 ++++++++++++++++++++++++++++++++++++-
 tools/perf/util/sort.h             |   8 +-
 14 files changed, 432 insertions(+), 114 deletions(-)

-- 
2.6.4