Commit 374855c5 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Arnaldo Carvalho de Melo
Browse files

tools lib traceevent: Add API to read time information from kbuffer 

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: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
[ Ported from trace-cmd.git ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200702185703.619656282@goodmis.org


Signed-off-by: default avatarTzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f18d5cf8

tools/lib/traceevent/kbuffer-parse.c

+28 −0
Original line number Diff line number Diff line
@@ -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

tools/lib/traceevent/kbuffer.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

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