[PATCH v2 0/2] tracing/hist: Add percentage histogram suffixes

Masami Hiramatsu (Google)
2022-08-05T01:35:19Z

Hi,

Here is the 2nd version of .percent and .graph suffixes for histogram
trigger to show the value in percentage and in bar-graph respectively.

This version uses div64_*() for calculating percentages and show an
error if it fails to calculate it.

This will help us to check the trend of the histogram instantly
without the post processing tool.

Here shows the example of the percentage and the bar graph of
the runtime of the running tasks.

/sys/kernel/tracing # echo hist:keys=pid:vals=runtime.percent,runtime.graph:sort
=pid >> events/sched/sched_stat_runtime/trigger
/sys/kernel/tracing # sleep 10
/sys/kernel/tracing # cat events/sched/sched_stat_runtime/hist
# event histogram
#
# trigger info: hist:keys=pid:vals=hitcount,runtime.percent,runtime.graph:sort=pid:size=2048 [active]
#

{ pid: 8 } hitcount: 11 runtime: 4.11 runtime: #
{ pid: 9 } hitcount: 4 runtime: 1.28 runtime:
{ pid: 14 } hitcount: 10 runtime: 2.22 runtime:
{ pid: 15 } hitcount: 1 runtime: 0.07 runtime:
{ pid: 16 } hitcount: 21 runtime: 3.35 runtime: #
{ pid: 57 } hitcount: 6 runtime: 2.41 runtime: #
{ pid: 61 } hitcount: 42 runtime: 9.79 runtime: ####
{ pid: 66 } hitcount: 5 runtime: 0.69 runtime:
{ pid: 147 } hitcount: 36 runtime: 45.33 runtime: ####################
{ pid: 8548 } hitcount: 9 runtime: 17.25 runtime: #######
{ pid: 8549 } hitcount: 8 runtime: 13.43 runtime: #####

Totals:
Hits: 153
Entries: 11
Dropped: 0

Thank you,

---

Masami Hiramatsu (Google) (2):
tracing: Add .percent suffix option to histogram values
tracing: Add .graph suffix option to histogram value

kernel/trace/trace.c | 3 +
kernel/trace/trace_events_hist.c | 129 ++++++++++++++++++++++++++++++++++++--
2 files changed, 124 insertions(+), 8 deletions(-)

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>