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

From: Namhyung Kim
Date: Mon Dec 14 2015 - 10:46:58 EST

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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

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Next message: Namhyung Kim: "[PATCH 1/6] perf hist: Pass struct sample to __hists__add_entry()"
Previous message: Rob Herring: "Re: [PATCH 1/3] Device tree binding documentation for gpio-switch"
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