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

From: Arnaldo Carvalho de Melo
Date: Fri Jul 03 2020 - 07:31:11 EST


Em Thu, Jul 02, 2020 at 02:53:45PM -0400, Steven Rostedt escreveu:
> From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
>
> 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@xxxxxxxxx
>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> [ Ported from trace-cmd.git ]
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

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