perf: Introduce a new "round of buffers read" pseudo event
Frederic Weisbecker [Sun, 2 May 2010 20:05:29 +0000 (22:05 +0200)]
In order to provide a more rubust and deterministic reordering
algorithm, we need to know when we reach a point where we just
did a pass through over every counter buffers to read every thing
they had.

This patch introduces a new PERF_RECORD_FINISHED_ROUND pseudo event
that only consist in an event header and doesn't need to contain
anything.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>

tools/perf/builtin-record.c
tools/perf/util/event.h

index d3981ac..6b77b28 100644 (file)
@@ -494,6 +494,29 @@ static void event__synthesize_guest_os(struct machine *machine, void *data)
                       " relocation symbol.\n", machine->pid);
 }
 
+static struct perf_event_header finished_round_event = {
+       .size = sizeof(struct perf_event_header),
+       .type = PERF_RECORD_FINISHED_ROUND,
+};
+
+static void mmap_read_all(void)
+{
+       int i, counter, thread;
+
+       for (i = 0; i < nr_cpu; i++) {
+               for (counter = 0; counter < nr_counters; counter++) {
+                       for (thread = 0; thread < thread_num; thread++) {
+                               if (mmap_array[i][counter][thread].base)
+                                       mmap_read(&mmap_array[i][counter][thread]);
+                       }
+
+               }
+       }
+
+       if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
+               write_output(&finished_round_event, sizeof(finished_round_event));
+}
+
 static int __cmd_record(int argc, const char **argv)
 {
        int i, counter;
@@ -726,16 +749,7 @@ static int __cmd_record(int argc, const char **argv)
                int hits = samples;
                int thread;
 
-               for (i = 0; i < nr_cpu; i++) {
-                       for (counter = 0; counter < nr_counters; counter++) {
-                               for (thread = 0;
-                                       thread < thread_num; thread++) {
-                                       if (mmap_array[i][counter][thread].base)
-                                               mmap_read(&mmap_array[i][counter][thread]);
-                               }
-
-                       }
-               }
+               mmap_read_all();
 
                if (hits == samples) {
                        if (done)
index b364da5..6cc1b1d 100644 (file)
@@ -84,11 +84,12 @@ struct build_id_event {
        char                     filename[];
 };
 
-enum perf_header_event_type { /* above any possible kernel type */
+enum perf_user_event_type { /* above any possible kernel type */
        PERF_RECORD_HEADER_ATTR                 = 64,
        PERF_RECORD_HEADER_EVENT_TYPE           = 65,
        PERF_RECORD_HEADER_TRACING_DATA         = 66,
        PERF_RECORD_HEADER_BUILD_ID             = 67,
+       PERF_RECORD_FINISHED_ROUND              = 68,
        PERF_RECORD_HEADER_MAX
 };