Re: [PATCH v5 03/17] perf ftrace: add option -t/--tid to filter by thread id

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sat, Jul 11, 2020 at 08:40:21PM +0800, Changbin Du escreveu:
> This allows us to trace single thread instead of the whole process.
> 
> Signed-off-by: Changbin Du <changbin.du@gmail.com>
> ---
>  tools/perf/Documentation/perf-ftrace.txt | 4 ++++
>  tools/perf/builtin-ftrace.c              | 2 ++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
> index d79560dea19f..e204bf6d50d8 100644
> --- a/tools/perf/Documentation/perf-ftrace.txt
> +++ b/tools/perf/Documentation/perf-ftrace.txt
> @@ -38,6 +38,10 @@ OPTIONS
>  --pid=::
>  	Trace on existing process id (comma separated list).
>  
> +-t::
> +--tid=::
> +	Trace on existing thread id (comma separated list).
> +


Humm, I just  tried:

[root@five ~]# yes > /dev/null &
[1] 18265
[root@five ~]# perf ftrace --tid 18265
^C[root@five ~]#

After waiting for a while, nothing, what am I doing wrong?

- Arnaldo


>  -a::
>  --all-cpus::
>  	Force system-wide collection.  Scripts run without a <command>
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index 244cc8e6bd60..1188b82c6541 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -515,6 +515,8 @@ int cmd_ftrace(int argc, const char **argv)
>  		    "Show available functions to filter"),
>  	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
>  		   "trace on existing process id"),
> +	OPT_STRING('t', "tid", &ftrace.target.tid, "tid",
> +		   "trace on existing thread id (exclusive to --pid)"),
>  	OPT_INCR('v', "verbose", &verbose,
>  		 "be more verbose"),
>  	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
> -- 
> 2.25.1
> 

-- 

- Arnaldo