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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2020-07-02 14:53:45 -0400
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-07-03 08:30:10 -0300
commit374855c5e4a76f7cc7f9aeb613c54929510eff18 (patch)
tree8cdcf0a22efc8a2b6f673e18fedf71d32e67d027 /tools/lib
parentf18d5cf86cdb58eb50cafb5a5e20943ec7a61b1f (diff)
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: Steven 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: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/traceevent/kbuffer-parse.c28
-rw-r--r--tools/lib/traceevent/kbuffer.h2
2 files changed, 30 insertions, 0 deletions
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
@@ -547,6 +547,34 @@ int kbuffer_load_subbuffer(struct kbuffer *kbuf, void *subbuffer)
}
/**
+ * 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
* @ts: The address to store the timestamp of the event (may be NULL to ignore)
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);