Re: [PATCH v2 01/15] tools lib traceevent: Add API to read time information from kbuffer

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org,
	Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Subject: Re: [PATCH v2 01/15] tools lib traceevent: Add API to read time information from kbuffer
Date: Fri, 3 Jul 2020 08:31:07 -0300	[thread overview]
Message-ID: <20200703113107.GD1320@kernel.org> (raw)
In-Reply-To: <20200702185703.619656282@goodmis.org>

Em Thu, Jul 02, 2020 at 02:53:45PM -0400, Steven Rostedt escreveu:
> From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
> 
> Add the functions kbuffer_subbuf_timestamp() and kbuffer_ptr_delta() to get
> the timing data stored in the ring buffer that is used to produced the time
> stamps of the records.
> 
> This is useful for tools like trace-cmd to be able to display the content of
> the read data to understand why the records show the time stamps that they
> do.
> 
> Link: http://lore.kernel.org/linux-trace-devel/20200625100516.365338-2-tz.stoyanov@gmail.com
> 
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> [ Ported from trace-cmd.git ]
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Humm, is that intentional, i.e. two signed-off-by you?

- Arnaldo

> ---
>  tools/lib/traceevent/kbuffer-parse.c | 28 ++++++++++++++++++++++++++++
>  tools/lib/traceevent/kbuffer.h       |  2 ++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/tools/lib/traceevent/kbuffer-parse.c b/tools/lib/traceevent/kbuffer-parse.c
> index 27f3b07fdae8..583db99aee94 100644
> --- a/tools/lib/traceevent/kbuffer-parse.c
> +++ b/tools/lib/traceevent/kbuffer-parse.c
> @@ -546,6 +546,34 @@ int kbuffer_load_subbuffer(struct kbuffer *kbuf, void *subbuffer)
>  	return 0;
>  }
>  
> +/**
> + * kbuffer_subbuf_timestamp - read the timestamp from a sub buffer
> + * @kbuf:      The kbuffer to load
> + * @subbuf:    The subbuffer to read from.
> + *
> + * Return the timestamp from a subbuffer.
> + */
> +unsigned long long kbuffer_subbuf_timestamp(struct kbuffer *kbuf, void *subbuf)
> +{
> +	return kbuf->read_8(subbuf);
> +}
> +
> +/**
> + * kbuffer_ptr_delta - read the delta field from a record
> + * @kbuf:      The kbuffer to load
> + * @ptr:       The record in the buffe.
> + *
> + * Return the timestamp delta from a record
> + */
> +unsigned int kbuffer_ptr_delta(struct kbuffer *kbuf, void *ptr)
> +{
> +	unsigned int type_len_ts;
> +
> +	type_len_ts = read_4(kbuf, ptr);
> +	return ts4host(kbuf, type_len_ts);
> +}
> +
> +
>  /**
>   * kbuffer_read_event - read the next event in the kbuffer subbuffer
>   * @kbuf:	The kbuffer to read from
> diff --git a/tools/lib/traceevent/kbuffer.h b/tools/lib/traceevent/kbuffer.h
> index ed4d697fc137..5fa8292e341b 100644
> --- a/tools/lib/traceevent/kbuffer.h
> +++ b/tools/lib/traceevent/kbuffer.h
> @@ -49,6 +49,8 @@ int kbuffer_load_subbuffer(struct kbuffer *kbuf, void *subbuffer);
>  void *kbuffer_read_event(struct kbuffer *kbuf, unsigned long long *ts);
>  void *kbuffer_next_event(struct kbuffer *kbuf, unsigned long long *ts);
>  unsigned long long kbuffer_timestamp(struct kbuffer *kbuf);
> +unsigned long long kbuffer_subbuf_timestamp(struct kbuffer *kbuf, void *subbuf);
> +unsigned int kbuffer_ptr_delta(struct kbuffer *kbuf, void *ptr);
>  
>  void *kbuffer_translate_data(int swap, void *data, unsigned int *size);
>  
> -- 
> 2.26.2
> 
> 

-- 

- Arnaldo