perf tools: Improve support for sessions with multiple events

By creating an perf_evlist out of the attributes in the perf.data file
header, so that we can use evlists and evsels when reading recorded
sessions in addition to when we record sessions.

More work is needed to allow tools to allow the user to select which
events are wanted when browsing sessions, be it just one or a subset of
them, aggregated or showed at the same time but with different
indications on the UI to allow seeing workloads thru different views at
the same time.

But the overall goal/trend is to more uniformly use evsels and evlists.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index dddcc7e..1c399ea 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -21,6 +21,8 @@
 
 #include "perf.h"
 #include "util/debug.h"
+#include "util/evlist.h"
+#include "util/evsel.h"
 #include "util/header.h"
 #include "util/session.h"
 
@@ -46,39 +48,6 @@
 static char		callchain_default_opt[] = "fractal,0.5";
 static symbol_filter_t	annotate_init;
 
-static struct hists *perf_session__hists_findnew(struct perf_session *self,
-						 u64 event_stream, u32 type,
-						 u64 config)
-{
-	struct rb_node **p = &self->hists_tree.rb_node;
-	struct rb_node *parent = NULL;
-	struct hists *iter, *new;
-
-	while (*p != NULL) {
-		parent = *p;
-		iter = rb_entry(parent, struct hists, rb_node);
-		if (iter->config == config)
-			return iter;
-
-
-		if (config > iter->config)
-			p = &(*p)->rb_right;
-		else
-			p = &(*p)->rb_left;
-	}
-
-	new = malloc(sizeof(struct hists));
-	if (new == NULL)
-		return NULL;
-	memset(new, 0, sizeof(struct hists));
-	new->event_stream = event_stream;
-	new->config = config;
-	new->type = type;
-	rb_link_node(&new->rb_node, parent, p);
-	rb_insert_color(&new->rb_node, &self->hists_tree);
-	return new;
-}
-
 static int perf_session__add_hist_entry(struct perf_session *session,
 					struct addr_location *al,
 					struct perf_sample *sample)
@@ -86,8 +55,7 @@
 	struct symbol *parent = NULL;
 	int err = 0;
 	struct hist_entry *he;
-	struct hists *hists;
-	struct perf_event_attr *attr;
+	struct perf_evsel *evsel;
 
 	if ((sort__has_parent || symbol_conf.use_callchain) && sample->callchain) {
 		err = perf_session__resolve_callchain(session, al->thread,
@@ -96,15 +64,19 @@
 			return err;
 	}
 
-	attr = perf_header__find_attr(sample->id, &session->header);
-	if (attr)
-		hists = perf_session__hists_findnew(session, sample->id, attr->type, attr->config);
-	else
-		hists = perf_session__hists_findnew(session, sample->id, 0, 0);
-	if (hists == NULL)
-		return -ENOMEM;
+	evsel = perf_evlist__id2evsel(session->evlist, sample->id);
+	if (evsel == NULL) {
+		/*
+		 * FIXME: Propagate this back, but at least we're in a builtin,
+		 * where exit() is allowed. ;-)
+		 */
+		ui__warning("Invalid %s file, contains samples with id not in "
+			    "its header!\n", input_name);
+		exit_browser(0);
+		exit(1);
+	}
 
-	he = __hists__add_entry(hists, al, parent, sample->period);
+	he = __hists__add_entry(&evsel->hists, al, parent, sample->period);
 	if (he == NULL)
 		return -ENOMEM;
 
@@ -120,52 +92,30 @@
 	 * code will not use it.
 	 */
 	if (al->sym != NULL && use_browser > 0) {
-		/*
-		 * All aggregated on the first sym_hist.
-		 */
 		struct annotation *notes = symbol__annotation(he->ms.sym);
+
+		assert(evsel != NULL);
+
+		err = -ENOMEM;
 		if (notes->src == NULL &&
-		    symbol__alloc_hist(he->ms.sym, 1) < 0)
-			err = -ENOMEM;
-		else
-			err = hist_entry__inc_addr_samples(he, 0, al->addr);
+		    symbol__alloc_hist(he->ms.sym, session->evlist->nr_entries) < 0)
+			goto out;
+
+		err = hist_entry__inc_addr_samples(he, evsel->idx, al->addr);
 	}
 
+	evsel->hists.stats.total_period += sample->period;
+	hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
+out:
 	return err;
 }
 
-static int add_event_total(struct perf_session *session,
-			   struct perf_sample *sample,
-			   struct perf_event_attr *attr)
-{
-	struct hists *hists;
-
-	if (attr)
-		hists = perf_session__hists_findnew(session, sample->id,
-						    attr->type, attr->config);
-	else
-		hists = perf_session__hists_findnew(session, sample->id, 0, 0);
-
-	if (!hists)
-		return -ENOMEM;
-
-	hists->stats.total_period += sample->period;
-	/*
-	 * FIXME: add_event_total should be moved from here to
-	 * perf_session__process_event so that the proper hist is passed to
-	 * the event_op methods.
-	 */
-	hists__inc_nr_events(hists, PERF_RECORD_SAMPLE);
-	session->hists.stats.total_period += sample->period;
-	return 0;
-}
 
 static int process_sample_event(union perf_event *event,
 				struct perf_sample *sample,
 				struct perf_session *session)
 {
 	struct addr_location al;
-	struct perf_event_attr *attr;
 
 	if (perf_event__preprocess_sample(event, session, &al, sample,
 					  annotate_init) < 0) {
@@ -182,27 +132,17 @@
 		return -1;
 	}
 
-	attr = perf_header__find_attr(sample->id, &session->header);
-
-	if (add_event_total(session, sample, attr)) {
-		pr_debug("problem adding event period\n");
-		return -1;
-	}
-
 	return 0;
 }
 
 static int process_read_event(union perf_event *event,
 			      struct perf_sample *sample __used,
-			      struct perf_session *session __used)
+			      struct perf_session *session)
 {
-	struct perf_event_attr *attr;
-
-	attr = perf_header__find_attr(event->read.id, &session->header);
-
+	struct perf_evsel *evsel = perf_evlist__id2evsel(session->evlist,
+							 event->read.id);
 	if (show_threads) {
-		const char *name = attr ? __event_name(attr->type, attr->config)
-				   : "unknown";
+		const char *name = evsel ? event_name(evsel) : "unknown";
 		perf_read_values_add_value(&show_threads_values,
 					   event->read.pid, event->read.tid,
 					   event->read.id,
@@ -211,7 +151,7 @@
 	}
 
 	dump_printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid,
-		    attr ? __event_name(attr->type, attr->config) : "FAIL",
+		    evsel ? event_name(evsel) : "FAIL",
 		    event->read.value);
 
 	return 0;
@@ -282,21 +222,20 @@
 	return ret + fprintf(fp, "\n#\n");
 }
 
-static int hists__tty_browse_tree(struct rb_root *tree, const char *help)
+static int hists__tty_browse_tree(struct perf_evlist *evlist, const char *help)
 {
-	struct rb_node *next = rb_first(tree);
+	struct perf_evsel *pos;
 
-	while (next) {
-		struct hists *hists = rb_entry(next, struct hists, rb_node);
+	list_for_each_entry(pos, &evlist->entries, node) {
+		struct hists *hists = &pos->hists;
 		const char *evname = NULL;
 
 		if (rb_first(&hists->entries) != rb_last(&hists->entries))
-			evname = __event_name(hists->type, hists->config);
+			evname = event_name(pos);
 
 		hists__fprintf_nr_sample_events(hists, evname, stdout);
 		hists__fprintf(hists, NULL, false, stdout);
 		fprintf(stdout, "\n\n");
-		next = rb_next(&hists->rb_node);
 	}
 
 	if (sort_order == default_sort_order &&
@@ -317,8 +256,9 @@
 static int __cmd_report(void)
 {
 	int ret = -EINVAL;
+	u64 nr_samples;
 	struct perf_session *session;
-	struct rb_node *next;
+	struct perf_evsel *pos;
 	const char *help = "For a higher level overview, try: perf report --sort comm,dso";
 
 	signal(SIGINT, sig_handler);
@@ -349,26 +289,24 @@
 	if (verbose > 2)
 		perf_session__fprintf_dsos(session, stdout);
 
-	next = rb_first(&session->hists_tree);
+	nr_samples = 0;
+	list_for_each_entry(pos, &session->evlist->entries, node) {
+		struct hists *hists = &pos->hists;
 
-	if (next == NULL) {
+		hists__collapse_resort(hists);
+		hists__output_resort(hists);
+		nr_samples += hists->stats.nr_events[PERF_RECORD_SAMPLE];
+	}
+
+	if (nr_samples == 0) {
 		ui__warning("The %s file has no samples!\n", input_name);
 		goto out_delete;
 	}
 
-	while (next) {
-		struct hists *hists;
-
-		hists = rb_entry(next, struct hists, rb_node);
-		hists__collapse_resort(hists);
-		hists__output_resort(hists);
-		next = rb_next(&hists->rb_node);
-	}
-
 	if (use_browser > 0)
-		hists__tui_browse_tree(&session->hists_tree, help, 0);
+		hists__tui_browse_tree(session->evlist, help);
 	else
-		hists__tty_browse_tree(&session->hists_tree, help);
+		hists__tty_browse_tree(session->evlist, help);
 
 out_delete:
 	/*