perf tools: Protect accesses the dso rbtrees/lists with a rw lock
To allow concurrent access, next step: refcount struct dso instances, so
that we can ditch unused them when the last map pointing to it goes
away.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-yk1k08etpd2aoe3tnrf0oizn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index dfd4197..0cf56d6 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -20,6 +20,7 @@
{
INIT_LIST_HEAD(&dsos->head);
dsos->root = RB_ROOT;
+ pthread_rwlock_init(&dsos->lock, NULL);
}
int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
@@ -81,15 +82,21 @@
return NULL;
}
-static void dsos__delete(struct dsos *dsos)
+static void dsos__exit(struct dsos *dsos)
{
struct dso *pos, *n;
+ pthread_rwlock_wrlock(&dsos->lock);
+
list_for_each_entry_safe(pos, n, &dsos->head, node) {
RB_CLEAR_NODE(&pos->rb_node);
list_del(&pos->node);
dso__delete(pos);
}
+
+ pthread_rwlock_unlock(&dsos->lock);
+
+ pthread_rwlock_destroy(&dsos->lock);
}
void machine__delete_threads(struct machine *machine)
@@ -110,7 +117,7 @@
void machine__exit(struct machine *machine)
{
map_groups__exit(&machine->kmaps);
- dsos__delete(&machine->dsos);
+ dsos__exit(&machine->dsos);
machine__exit_vdso(machine);
zfree(&machine->root_dir);
zfree(&machine->current_tid);
@@ -496,11 +503,13 @@
{
struct dso *dso;
- dso = dsos__find(&machine->dsos, m->name, true);
+ pthread_rwlock_wrlock(&machine->dsos.lock);
+
+ dso = __dsos__find(&machine->dsos, m->name, true);
if (!dso) {
- dso = dsos__addnew(&machine->dsos, m->name);
+ dso = __dsos__addnew(&machine->dsos, m->name);
if (dso == NULL)
- return NULL;
+ goto out_unlock;
if (machine__is_host(machine))
dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
@@ -515,6 +524,8 @@
dso__set_long_name(dso, strdup(filename), true);
}
+out_unlock:
+ pthread_rwlock_unlock(&machine->dsos.lock);
return dso;
}
@@ -1156,6 +1167,8 @@
struct dso *kernel = NULL;
struct dso *dso;
+ pthread_rwlock_rdlock(&machine->dsos.lock);
+
list_for_each_entry(dso, &machine->dsos.head, node) {
/*
@@ -1184,6 +1197,8 @@
break;
}
+ pthread_rwlock_unlock(&machine->dsos.lock);
+
if (kernel == NULL)
kernel = machine__findnew_dso(machine, kmmap_prefix);
if (kernel == NULL)
@@ -1948,5 +1963,5 @@
struct dso *machine__findnew_dso(struct machine *machine, const char *filename)
{
- return __dsos__findnew(&machine->dsos, filename);
+ return dsos__findnew(&machine->dsos, filename);
}