Re: [PATCH v5 0/6] tracing/hist: Add percentage histogram suffixes

[Tom Zanussi <zanussi@kernel.org>]

Hi Masami,

On Sun, 2022-09-04 at 13:12 +0900, Masami Hiramatsu (Google) wrote:
> Hi,
> 
> Here is the 5th version of .percent and .graph suffixes for histogram
> trigger to show the value in percentage and in bar-graph
> respectively.
> The previous version is here;
> 
> https://lore.kernel.org/all/166157298537.348924.2537162090505397377.stgit@devnote2
> 
> This version updated the last patch to add "nohitcount" option for
> supressing display of hitcount according to Tom's suggestion[5/6],
> fix README file[4/6], and update the histogram document[6/6].
> 
> This will help us to check the trend of the histogram instantly
> without any post processing tool.
> 
> Here shows an example of the percentage and the bar graph of
> the runtime of the running tasks without raw hitcount field.
> 
>   # cd /sys/kernel/debug/tracing/
>   # echo
> hist:keys=pid:vals=hitcount.percent,hitcount.graph:sort=pid:NOHC > \
>         events/sched/sched_stat_runtime/trigger
>   # sleep 10
>   # cat events/sched/sched_stat_runtime/hist
>  # event histogram
>  #
>  # trigger info:
> hist:keys=pid:vals=hitcount.percent,hitcount.graph:sort=pid:size=2048
> :nohitcount [active]
>  #
>  
>  { pid:         14 }  hitcount (%):   6.91  hitcount:
> ##                  
>  { pid:         16 }  hitcount (%):   1.13 
> hitcount:                     
>  { pid:         57 }  hitcount (%):   6.99  hitcount:
> ##                  
>  { pid:         61 }  hitcount (%):  55.28  hitcount:
> ####################
>  { pid:         67 }  hitcount (%):   5.52  hitcount:
> ##                  
>  { pid:         69 }  hitcount (%):  20.08  hitcount:
> #######             
>  { pid:         71 }  hitcount (%):   0.40 
> hitcount:                     
>  { pid:         77 }  hitcount (%):   0.97 
> hitcount:                     
>  { pid:         78 }  hitcount (%):   0.56 
> hitcount:                     
>  { pid:        145 }  hitcount (%):   1.13 
> hitcount:                     
>  { pid:        153 }  hitcount (%):   0.48 
> hitcount:                     
>  { pid:        154 }  hitcount (%):   0.48 
> hitcount:                     
>  
>  Totals:
>      Hits: 1230
>      Entries: 12
>      Dropped: 0
> 
> 
> With the NOHC (or nohitcount) option, the histogram will skip
> display of raw hitcount, but it will allow to display percent
> and graph of hitcount.
> 
> Trigger                      Result
> val=runtime               -> Show hitcount and runtime
> val=runtime:NOHC          -> Show runtime
> val=hitcount:NOHC         -> Error
> (noval)                   -> show hitcount
> (noval):NOHC              -> Error
> val=hitcount.parcent      -> show hitcount and hitcount%
> val=hitcount.parcent:NOHC -> show hitcount%

It all looks good to me, thanks!  For the whole set:

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>

Tom



> 
> Thank you,
> 
> ---
> 
> Masami Hiramatsu (Google) (5):
>       tracing: Fix to check event_mutex is held while accessing
> trigger list
>       tracing: Add .percent suffix option to histogram values
>       tracing: Add .graph suffix option to histogram value
>       tracing: Add nohitcount option for suppressing display of raw
> hitcount
>       tracing: docs: Update histogram doc for .percent/.graph and
> 'nohitcount'
> 
> Tom Zanussi (1):
>       tracing: Allow multiple hitcount values in histograms
> 
> 
>  Documentation/trace/histogram.rst   |   10 ++
>  kernel/trace/trace.c                |    7 +
>  kernel/trace/trace_events_hist.c    |  177
> ++++++++++++++++++++++++++++++-----
>  kernel/trace/trace_events_trigger.c |    3 -
>  4 files changed, 171 insertions(+), 26 deletions(-)
> 
> --
> Masami Hiramatsu (Google) <mhiramat@kernel.org>