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Date:   Wed, 8 Jul 2020 14:39:59 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Changbin Du <changbin.du@gmail.com>
Cc:     Jiri Olsa <jolsa@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 00/17] perf: ftrace enhancement
Message-ID: <20200708173959.GD22437@kernel.org>
References: <20200708164605.31245-1-changbin.du@gmail.com>
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Em Thu, Jul 09, 2020 at 12:45:48AM +0800, Changbin Du escreveu:
> Here is a glance of all ftrace functions with this serias:
> 
> $ sudo perf ftrace -h
 
>  Usage: perf ftrace [<options>] [<command>]
>     or: perf ftrace [<options>] -- <command> [<options>]
> 
>     -a, --all-cpus        system-wide collection from all CPUs
>     -C, --cpu <cpu>       list of cpus to monitor
>     -d, --delay <n>       ms to wait before starting tracing after program start
>     -D, --graph-depth <n>
>                           Max depth for function graph tracer (This option is deprecated)
>     -F, --funcs           Show available functions to filter
>     -G, --graph-funcs <func>
>                           trace given functions using function_graph tracer
>     -g, --nograph-funcs <func>
>                           Set nograph filter on given functions
>     -m, --buffer-size <size>
>                           size of per cpu buffer
>     -N, --notrace-funcs <func>
>                           do not trace given functions
>     -p, --pid <pid>       trace on existing process id
>     -t, --tid <tid>       trace on existing thread id (exclusive to --pid)
>     -T, --trace-funcs <func>
>                           trace given functions using function tracer
>     -t, --tracer <tracer>
>                           tracer to use: function or function_graph (This option is deprecated)
>     -v, --verbose         be more verbose
>         --func-opts <options>
>                           function tracer options, available options: call-graph,irq-info
>         --graph-opts <options>
>                           graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>
>         --inherit         trace children processes
> 
> v3:
>   o add --func-opts and --graph-opts to set tracer specific options.
>   o support units as a suffix for option '-m/--buffer-size'.

Thanks for working on this! -d/--delay:

[acme@quaco perf]$ perf record -h delay

 Usage: perf record [<options>] [<command>]
    or: perf record [<options>] -- <command> [<options>]

    -D, --delay <n>       ms to wait before starting measurement after program start

[acme@quaco perf]$

[acme@quaco perf]$ perf stat -h --delay

 Usage: perf stat [<options>] [<command>]

    -D, --delay <n>       ms to wait before starting measurement after program start

[acme@quaco perf]$

[acme@quaco perf]$ perf trace -h -D

 Usage: perf trace [<options>] [<command>]
    or: perf trace [<options>] -- <command> [<options>]
    or: perf trace record [<options>] [<command>]
    or: perf trace record [<options>] -- <command> [<options>]

    -D, --delay <n>       ms to wait before starting measurement after program start

Perhaps we can move --graph-depth to --graph-opts and make -D/--delay be
just like with 'perf record', 'perf stat' and 'perf trace'?

Will be super nice if one can go from:

	perf stat --delay 100 workload

to see the default set of counters to:

	perf ftrace --delay 100 workload

to get the ftrace output for that.

Ditto seeing the syscalls strace-like with:

	perf trace --delay 100 workload

Regards,

- Arnaldo