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>

8 files changed, 98 insertions, 66 deletions

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index f6fc8f651a25..281b60e5fc7b 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -7,6 +7,7 @@
 #include "types.h"
 #include "xyarray.h"
 #include "cgroup.h"
+#include "hist.h"
  
 struct perf_counts_values {
         union {
@@ -51,6 +52,7 @@ struct perf_evsel {
         struct xyarray          *id;
         struct perf_counts      *counts;
         int                     idx;
+        struct hists            hists;
         char                    *name;
         void                    *priv;
         struct cgroup_sel       *cgrp;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 72c124dc5781..108b0db7bbef 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -969,37 +969,6 @@ bool perf_header__sample_id_all(const struct perf_header *header)
         return value;
 }
 
-struct perf_event_attr *
-perf_header__find_attr(u64 id, struct perf_header *header)
-{
-        int i;
-
-        /*
-         * We set id to -1 if the data file doesn't contain sample
-         * ids. This can happen when the data file contains one type
-         * of event and in that case, the header can still store the
-         * event attribute information. Check for this and avoid
-         * walking through the entire list of ids which may be large.
-         */
-        if (id == -1ULL) {
-                if (header->attrs > 0)
-                        return &header->attr[0]->attr;
-                return NULL;
-        }
-
-        for (i = 0; i < header->attrs; i++) {
-                struct perf_header_attr *attr = header->attr[i];
-                int j;
-
-                for (j = 0; j < attr->ids; j++) {
-                        if (attr->id[j] == id)
-                                return &attr->attr;
-                }
-        }
-
-        return NULL;
-}
-
 int perf_event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
                                 perf_event__handler_t process,
                                 struct perf_session *session)
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index f042cebcec1e..2fab13348aab 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -85,8 +85,6 @@ int perf_header_attr__add_id(struct perf_header_attr *self, u64 id);
 
 u64 perf_header__sample_type(struct perf_header *header);
 bool perf_header__sample_id_all(const struct perf_header *header);
-struct perf_event_attr *
-perf_header__find_attr(u64 id, struct perf_header *header);
 void perf_header__set_feat(struct perf_header *self, int feat);
 void perf_header__clear_feat(struct perf_header *self, int feat);
 bool perf_header__has_feat(const struct perf_header *self, int feat);
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index f7ad6bdbc667..627a02e03c57 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -984,8 +984,12 @@ size_t hists__fprintf_nr_events(struct hists *self, FILE *fp)
         size_t ret = 0;
 
         for (i = 0; i < PERF_RECORD_HEADER_MAX; ++i) {
-                const char *name = perf_event__name(i);
+                const char *name;
 
+                if (self->stats.nr_events[i] == 0)
+                        continue;
+
+                name = perf_event__name(i);
                 if (!strcmp(name, "UNKNOWN"))
                         continue;
 
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 37c79089de09..0d38b435827b 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -42,13 +42,10 @@ enum hist_column {
 };
 
 struct hists {
-        struct rb_node          rb_node;
         struct rb_root          entries;
         u64                     nr_entries;
         struct events_stats     stats;
-        u64                     config;
         u64                     event_stream;
-        u32                     type;
         u16                     col_len[HISTC_NR_COLS];
         /* Best would be to reuse the session callchain cursor */
         struct callchain_cursor callchain_cursor;
@@ -87,6 +84,8 @@ u16 hists__col_len(struct hists *self, enum hist_column col);
 void hists__set_col_len(struct hists *self, enum hist_column col, u16 len);
 bool hists__new_col_len(struct hists *self, enum hist_column col, u16 len);
 
+struct perf_evlist;
+
 #ifdef NO_NEWT_SUPPORT
 static inline int hists__browse(struct hists *self __used,
                                 const char *helpline __used,
@@ -95,9 +94,8 @@ static inline int hists__browse(struct hists *self __used,
         return 0;
 }
 
-static inline int hists__tui_browse_tree(struct rb_root *self __used,
-                                         const char *help __used,
-                                         int evidx __used)
+static inline int hists__tui_browse_tree(struct perf_evlist *evlist __used,
+                                         const char *help __used)
 {
         return 0;
 }
@@ -118,7 +116,7 @@ int hist_entry__tui_annotate(struct hist_entry *self, int evidx);
 #define KEY_LEFT NEWT_KEY_LEFT
 #define KEY_RIGHT NEWT_KEY_RIGHT
 
-int hists__tui_browse_tree(struct rb_root *self, const char *help, int evidx);
+int hists__tui_browse_tree(struct perf_evlist *evlist, const char *help);
 #endif
 
 unsigned int hists__sort_list_width(struct hists *self);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index a3a871f7bda3..0d414199889d 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -7,10 +7,52 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 
+#include "evlist.h"
+#include "evsel.h"
 #include "session.h"
 #include "sort.h"
 #include "util.h"
 
+static int perf_session__read_evlist(struct perf_session *session)
+{
+        int i, j;
+
+        session->evlist = perf_evlist__new(NULL, NULL);
+        if (session->evlist == NULL)
+                return -ENOMEM;
+
+        for (i = 0; i < session->header.attrs; ++i) {
+                struct perf_header_attr *hattr = session->header.attr[i];
+                struct perf_evsel *evsel = perf_evsel__new(&hattr->attr, i);
+
+                if (evsel == NULL)
+                        goto out_delete_evlist;
+                /*
+                 * Do it before so that if perf_evsel__alloc_id fails, this
+                 * entry gets purged too at perf_evlist__delete().
+                 */
+                perf_evlist__add(session->evlist, evsel);
+                /*
+                 * We don't have the cpu and thread maps on the header, so
+                 * for allocating the perf_sample_id table we fake 1 cpu and
+                 * hattr->ids threads.
+                 */
+                if (perf_evsel__alloc_id(evsel, 1, hattr->ids))
+                        goto out_delete_evlist;
+
+                for (j = 0; j < hattr->ids; ++j)
+                        perf_evlist__id_hash(session->evlist, evsel, 0, j,
+                                             hattr->id[j]);
+        }
+
+        return 0;
+
+out_delete_evlist:
+        perf_evlist__delete(session->evlist);
+        session->evlist = NULL;
+        return -ENOMEM;
+}
+
 static int perf_session__open(struct perf_session *self, bool force)
 {
         struct stat input_stat;
@@ -56,6 +98,11 @@ static int perf_session__open(struct perf_session *self, bool force)
                 goto out_close;
         }
 
+        if (perf_session__read_evlist(self) < 0) {
+                pr_err("Not enough memory to read the event selector list\n");
+                goto out_close;
+        }
+
         self->size = input_stat.st_size;
         return 0;
 
@@ -141,7 +188,6 @@ struct perf_session *perf_session__new(const char *filename, int mode,
         memcpy(self->filename, filename, len);
         self->threads = RB_ROOT;
         INIT_LIST_HEAD(&self->dead_threads);
-        self->hists_tree = RB_ROOT;
         self->last_match = NULL;
         /*
          * On 64bit we can mmap the data file in one go. No need for tiny mmap
@@ -1137,3 +1183,18 @@ size_t perf_session__fprintf_dsos_buildid(struct perf_session *self, FILE *fp,
         size_t ret = machine__fprintf_dsos_buildid(&self->host_machine, fp, with_hits);
         return ret + machines__fprintf_dsos_buildid(&self->machines, fp, with_hits);
 }
+
+size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp)
+{
+        struct perf_evsel *pos;
+        size_t ret = fprintf(fp, "Aggregated stats:\n");
+
+        ret += hists__fprintf_nr_events(&session->hists, fp);
+
+        list_for_each_entry(pos, &session->evlist->entries, node) {
+                ret += fprintf(fp, "%s stats:\n", event_name(pos));
+                ret += hists__fprintf_nr_events(&pos->hists, fp);
+        }
+
+        return ret;
+}
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 977b3a1b14aa..05dd7bcb9453 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -34,12 +34,12 @@ struct perf_session {
         struct thread           *last_match;
         struct machine          host_machine;
         struct rb_root          machines;
-        struct rb_root          hists_tree;
+        struct perf_evlist      *evlist;
         /*
-         * FIXME: should point to the first entry in hists_tree and
-         *        be a hists instance. Right now its only 'report'
-         *        that is using ->hists_tree while all the rest use
-         *        ->hists.
+         * FIXME: Need to split this up further, we need global
+         *        stats + per event stats. 'perf diff' also needs
+         *        to properly support multiple events in a single
+         *        perf.data file.
          */
         struct hists            hists;
         u64                     sample_type;
@@ -151,11 +151,7 @@ size_t perf_session__fprintf_dsos(struct perf_session *self, FILE *fp);
 size_t perf_session__fprintf_dsos_buildid(struct perf_session *self,
                                           FILE *fp, bool with_hits);
 
-static inline
-size_t perf_session__fprintf_nr_events(struct perf_session *self, FILE *fp)
-{
-        return hists__fprintf_nr_events(&self->hists, fp);
-}
+size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp);
 
 static inline int perf_session__parse_sample(struct perf_session *session,
                                              const union perf_event *event,
diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index c98e6f81d285..f3af4fe5cdc4 100644
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -7,6 +7,8 @@
 #include <newt.h>
 #include <linux/rbtree.h>
 
+#include "../../evsel.h"
+#include "../../evlist.h"
 #include "../../hist.h"
 #include "../../pstack.h"
 #include "../../sort.h"
@@ -987,31 +989,33 @@ out:
         return key;
 }
 
-int hists__tui_browse_tree(struct rb_root *self, const char *help, int evidx)
+int hists__tui_browse_tree(struct perf_evlist *evlist, const char *help)
 {
-        struct rb_node *first = rb_first(self), *nd = first, *next;
-        int key = 0;
+        struct perf_evsel *pos;
 
-        while (nd) {
-                struct hists *hists = rb_entry(nd, struct hists, rb_node);
-                const char *ev_name = __event_name(hists->type, hists->config);
+        pos = list_entry(evlist->entries.next, struct perf_evsel, node);
+        while (pos) {
+                struct hists *hists = &pos->hists;
+                const char *ev_name = event_name(pos);
+                int key = hists__browse(hists, help, ev_name, pos->idx);
 
-                key = hists__browse(hists, help, ev_name, evidx);
                 switch (key) {
                 case NEWT_KEY_TAB:
-                        next = rb_next(nd);
-                        if (next)
-                                nd = next;
+                        if (pos->node.next == &evlist->entries)
+                                pos = list_entry(evlist->entries.next, struct perf_evsel, node);
+                        else
+                                pos = list_entry(pos->node.next, struct perf_evsel, node);
                         break;
                 case NEWT_KEY_UNTAB:
-                        if (nd == first)
-                                continue;
-                        nd = rb_prev(nd);
+                        if (pos->node.prev == &evlist->entries)
+                                pos = list_entry(evlist->entries.prev, struct perf_evsel, node);
+                        else
+                                pos = list_entry(pos->node.prev, struct perf_evsel, node);
                         break;
                 default:
                         return key;
                 }
         }
 
-        return key;
+        return 0;
 }