perf session: Add hooks to allow transparent decoding of AUX area tracing data

Hook into session processing so that AUX area decoding can synthesize
events transparently to the tools.

The advantages of transparent decoding are that tools can be used
directly with perf.data files containing AUX area tracing data, which is
easier for the user and more efficient than having a separate decoding
tool.

This will work as follows:

1. Tools will feed auxtrace events to the decoder using
   perf_tool->auxtrace() (support for that still to come).

2. The decoder can process side-band events as needed due
   to the auxtrace->process_event() hook.

3. The decoder can deliver synthesized events into the
   event stream using perf_session__deliver_synth_event().

Note the expectation is that decoding will work on data that is
time-ordered with respect to the per-cpu or per-thread contexts that
were recorded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-9-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index 7ab4850703f0..199fc27b3954 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 
 #include "../perf.h"
+#include "session.h"
 
 union perf_event;
 struct perf_session;
@@ -32,6 +33,24 @@ struct record_opts;
 struct auxtrace_info_event;
 
 /**
+ * struct auxtrace - session callbacks to allow AUX area data decoding.
+ * @process_event: lets the decoder see all session events
+ * @flush_events: process any remaining data
+ * @free_events: free resources associated with event processing
+ * @free: free resources associated with the session
+ */
+struct auxtrace {
+        int (*process_event)(struct perf_session *session,
+                             union perf_event *event,
+                             struct perf_sample *sample,
+                             struct perf_tool *tool);
+        int (*flush_events)(struct perf_session *session,
+                            struct perf_tool *tool);
+        void (*free_events)(struct perf_session *session);
+        void (*free)(struct perf_session *session);
+};
+
+/**
  * struct auxtrace_mmap - records an mmap of the auxtrace buffer.
  * @base: address of mapped area
  * @userpg: pointer to buffer's perf_event_mmap_page
@@ -168,4 +187,40 @@ int perf_event__synthesize_auxtrace_info(struct auxtrace_record *itr,
                                          struct perf_session *session,
                                          perf_event__handler_t process);
 
+static inline int auxtrace__process_event(struct perf_session *session,
+                                          union perf_event *event,
+                                          struct perf_sample *sample,
+                                          struct perf_tool *tool)
+{
+        if (!session->auxtrace)
+                return 0;
+
+        return session->auxtrace->process_event(session, event, sample, tool);
+}
+
+static inline int auxtrace__flush_events(struct perf_session *session,
+                                         struct perf_tool *tool)
+{
+        if (!session->auxtrace)
+                return 0;
+
+        return session->auxtrace->flush_events(session, tool);
+}
+
+static inline void auxtrace__free_events(struct perf_session *session)
+{
+        if (!session->auxtrace)
+                return;
+
+        return session->auxtrace->free_events(session);
+}
+
+static inline void auxtrace__free(struct perf_session *session)
+{
+        if (!session->auxtrace)
+                return;
+
+        return session->auxtrace->free(session);
+}
+
 #endif