[PATCHSET 00/10] perf tools: Support dynamic sort keys for tracepoints (v4)

From: Namhyung Kim
Date: Tue Dec 22 2015 - 12:08:03 EST


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.

* changes in v4)
- support '<event>.*' syntax for dynamic sort key
- skip unrelated dynamic fields in the output
- add 'trace_fields' sort key (Jiri)
- reuse get_trace_output function (Jiri)

* changes in v3)
- save trace_output for dynamic entries (Jiri)
- update field length for each entry

* changes in v2)
- add 'trace' sort key and make it default (Jiri)
- add '--raw-trace' option and '/raw' field modifier (Jiri)
- support event name shortcuts (David)


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 and the event name can
be simplified (or even omitted in a couple of ways (see patch 10/10):

$ perf report -s comm,switch.next_pid,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'.

Also now it add a new 'trace' sort key to print whole trace output.
Below is the output using sched_switch plugin.

$ perf report -s trace --stdio
...
# Overhead Trace output
# ........ ...................................................
#
9.48% swapper/0:0 [120] R ==> transmission-gt:17773 [120]
9.48% transmission-gt:17773 [120] S ==> swapper/0:0 [120]
9.04% swapper/2:0 [120] R ==> transmission-gt:17773 [120]
8.92% transmission-gt:17773 [120] S ==> swapper/2:0 [120]
5.25% swapper/0:0 [120] R ==> kworker/0:1H:109 [100]
5.21% kworker/0:1H:109 [100] S ==> swapper/0:0 [120]
1.78% swapper/3:0 [120] R ==> transmission-gt:17773 [120]
1.78% transmission-gt:17773 [120] S ==> swapper/3:0 [120]
1.53% Xephyr:6524 [120] S ==> swapper/0:0 [120]
1.53% swapper/0:0 [120] R ==> Xephyr:6524 [120]
1.17% swapper/2:0 [120] R ==> irq/33-iwlwifi:233 [49]
1.13% irq/33-iwlwifi:233 [49] S ==> swapper/2:0 [120]
...

The 'trace_fields' sort key is to show each fields separately. This
is actually same as using -s 'sched_switch.*' in this case, but the
'trace_fields' sort key also works for more than one events:

$ perf report -s trace_fields --stdio
...
# Overhead prev_comm prev_pid prev_prio prev_state next_comm next_pid next_prio
# ........ ........... ......... ......... .......... ............ ........ .........
#
3.82% swapper/0 0 120 0 netctl-auto 18711 120
3.75% netctl-auto 18711 120 1 swapper/0 0 120
2.24% swapper/1 0 120 0 netctl-auto 18709 120
2.24% netctl-auto 18709 120 1 swapper/1 0 120
1.80% swapper/2 0 120 0 rcu_preempt 7 120
1.80% swapper/2 0 120 0 netctl-auto 18711 120
1.80% rcu_preempt 7 120 1 swapper/2 0 120
1.80% netctl-auto 18711 120 1 swapper/2 0 120
...

If a data file has only tracepoint events, the 'trace' sort key will
be used by default. However, if user gave --raw-trace option also,
it'll use 'trace_fields' instead.

This is available on 'perf/dynamic-sort-v4' 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 (13):
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[s]
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
perf tools: Add 'trace' sort key
perf tools: Add --raw-trace option
perf tools: Support shortcuts for events in dynamic sort keys
perf tools: Support '<event>.*' dynamic sort key
perf tools: Skip dynamic fields not defined for current event
perf tools: Add 'trace_fields' dynamic sort key
perf tools: Make 'trace' or 'trace_fields' sort key default for tracepoint events

tools/lib/traceevent/event-parse.c | 125 +++----
tools/lib/traceevent/event-parse.h | 4 +
tools/perf/Documentation/perf-report.txt | 3 +
tools/perf/Documentation/perf-top.txt | 3 +
tools/perf/builtin-annotate.c | 9 +-
tools/perf/builtin-diff.c | 13 +-
tools/perf/builtin-report.c | 4 +-
tools/perf/builtin-top.c | 16 +-
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/ui/browsers/hists.c | 7 +-
tools/perf/ui/gtk/hists.c | 4 +-
tools/perf/ui/hist.c | 2 +-
tools/perf/ui/stdio/hist.c | 6 +-
tools/perf/util/hist.c | 38 ++-
tools/perf/util/hist.h | 19 +-
tools/perf/util/sort.c | 539 ++++++++++++++++++++++++++++++-
tools/perf/util/sort.h | 10 +-
tools/perf/util/symbol.h | 3 +-
21 files changed, 700 insertions(+), 133 deletions(-)

--
2.6.4

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