perf tools: Release thread resources on PERF_RECORD_EXIT

For long running sessions with many threads with short lifetimes the
amount of memory that the buildid process takes is too much.

Since we don't have hist_entries that may be pointing to them, we can
just release the resources associated with each thread when the exit
(PERF_RECORD_EXIT) event is received.

For normal processing we need to annotate maps with hits, and thus
hist_entries pointing to it and drop the ones that had none. Will be
done in a followup patch.

Cc: David S. Miller <davem@davemloft.net>
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>

5 files changed, 61 insertions, 0 deletions

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 5c26e2d314af..e437edb72417 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -12,6 +12,7 @@
 #include "event.h"
 #include "symbol.h"
 #include <linux/kernel.h>
+#include "debug.h"
 
 static int build_id__mark_dso_hit(event_t *event, struct perf_session *session)
 {
@@ -34,10 +35,27 @@ static int build_id__mark_dso_hit(event_t *event, struct perf_session *session)
         return 0;
 }
 
+static int event__exit_del_thread(event_t *self, struct perf_session *session)
+{
+        struct thread *thread = perf_session__findnew(session, self->fork.tid);
+
+        dump_printf("(%d:%d):(%d:%d)\n", self->fork.pid, self->fork.tid,
+                    self->fork.ppid, self->fork.ptid);
+
+        if (thread) {
+                rb_erase(&thread->rb_node, &session->threads);
+                session->last_match = NULL;
+                thread__delete(thread);
+        }
+
+        return 0;
+}
+
 struct perf_event_ops build_id__mark_dso_hit_ops = {
         .sample = build_id__mark_dso_hit,
         .mmap   = event__process_mmap,
         .fork   = event__process_task,
+        .exit   = event__exit_del_thread,
 };
 
 char *dso__build_id_filename(struct dso *self, char *bf, size_t size)
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 37cab9038538..2ddbae319de5 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -228,6 +228,39 @@ void map_groups__init(struct map_groups *self)
         self->machine = NULL;
 }
 
+static void maps__delete(struct rb_root *self)
+{
+        struct rb_node *next = rb_first(self);
+
+        while (next) {
+                struct map *pos = rb_entry(next, struct map, rb_node);
+
+                next = rb_next(&pos->rb_node);
+                rb_erase(&pos->rb_node, self);
+                map__delete(pos);
+        }
+}
+
+static void maps__delete_removed(struct list_head *self)
+{
+        struct map *pos, *n;
+
+        list_for_each_entry_safe(pos, n, self, node) {
+                list_del(&pos->node);
+                map__delete(pos);
+        }
+}
+
+void map_groups__exit(struct map_groups *self)
+{
+        int i;
+
+        for (i = 0; i < MAP__NR_TYPES; ++i) {
+                maps__delete(&self->maps[i]);
+                maps__delete_removed(&self->removed_maps[i]);
+        }
+}
+
 void map_groups__flush(struct map_groups *self)
 {
         int type;
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 3b2f706c0ba2..20eba420ddae 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -127,6 +127,7 @@ size_t __map_groups__fprintf_maps(struct map_groups *self,
 void maps__insert(struct rb_root *maps, struct map *map);
 struct map *maps__find(struct rb_root *maps, u64 addr);
 void map_groups__init(struct map_groups *self);
+void map_groups__exit(struct map_groups *self);
 int map_groups__clone(struct map_groups *self,
                       struct map_groups *parent, enum map_type type);
 size_t map_groups__fprintf(struct map_groups *self, int verbose, FILE *fp);
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 9a448b47400c..8c72d888e449 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -62,6 +62,13 @@ static struct thread *thread__new(pid_t pid)
         return self;
 }
 
+void thread__delete(struct thread *self)
+{
+        map_groups__exit(&self->mg);
+        free(self->comm);
+        free(self);
+}
+
 int thread__set_comm(struct thread *self, const char *comm)
 {
         int err;
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index ee6bbcf277ca..688500ff826f 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -20,6 +20,8 @@ struct thread {
 
 struct perf_session;
 
+void thread__delete(struct thread *self);
+
 int find_all_tid(int pid, pid_t ** all_tid);
 int thread__set_comm(struct thread *self, const char *comm);
 int thread__comm_len(struct thread *self);