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

From: Steven Rostedt
Date: Mon Aug 01 2022 - 16:59:31 EST


On Mon, 1 Aug 2022 12:00:40 +0900
"Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> wrote:

> Here are a couple of patches to add .percent and .graph histogram
> value suffixes to show the value in percentage and in bar-graph.
>
> 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
>

Hi Masami,

Thanks for this as well. But as it's a new feature, and I freeze new
features when the merge window starts, I'll add this to my queue for the
next window.

-- Steve