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/dso.c b/tools/perf/util/dso.c
index 5ec9e89..ff0204a 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -889,8 +889,8 @@
* Either one of the dso or name parameter must be non-NULL or the
* function will not work.
*/
-static struct dso *dso__findlink_by_longname(struct rb_root *root,
- struct dso *dso, const char *name)
+static struct dso *__dso__findlink_by_longname(struct rb_root *root,
+ struct dso *dso, const char *name)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
@@ -937,10 +937,10 @@
return NULL;
}
-static inline struct dso *
-dso__find_by_longname(const struct rb_root *root, const char *name)
+static inline struct dso *__dso__find_by_longname(struct rb_root *root,
+ const char *name)
{
- return dso__findlink_by_longname((struct rb_root *)root, NULL, name);
+ return __dso__findlink_by_longname(root, NULL, name);
}
void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
@@ -1149,14 +1149,20 @@
return have_build_id;
}
-void dsos__add(struct dsos *dsos, struct dso *dso)
+void __dsos__add(struct dsos *dsos, struct dso *dso)
{
list_add_tail(&dso->node, &dsos->head);
- dso__findlink_by_longname(&dsos->root, dso, NULL);
+ __dso__findlink_by_longname(&dsos->root, dso, NULL);
}
-struct dso *dsos__find(const struct dsos *dsos, const char *name,
- bool cmp_short)
+void dsos__add(struct dsos *dsos, struct dso *dso)
+{
+ pthread_rwlock_wrlock(&dsos->lock);
+ __dsos__add(dsos, dso);
+ pthread_rwlock_unlock(&dsos->lock);
+}
+
+struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
{
struct dso *pos;
@@ -1166,15 +1172,24 @@
return pos;
return NULL;
}
- return dso__find_by_longname(&dsos->root, name);
+ return __dso__find_by_longname(&dsos->root, name);
}
-struct dso *dsos__addnew(struct dsos *dsos, const char *name)
+struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
+{
+ struct dso *dso;
+ pthread_rwlock_rdlock(&dsos->lock);
+ dso = __dsos__find(dsos, name, cmp_short);
+ pthread_rwlock_unlock(&dsos->lock);
+ return dso;
+}
+
+struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
{
struct dso *dso = dso__new(name);
if (dso != NULL) {
- dsos__add(dsos, dso);
+ __dsos__add(dsos, dso);
dso__set_basename(dso);
}
return dso;
@@ -1182,9 +1197,18 @@
struct dso *__dsos__findnew(struct dsos *dsos, const char *name)
{
- struct dso *dso = dsos__find(dsos, name, false);
+ struct dso *dso = __dsos__find(dsos, name, false);
- return dso ? dso : dsos__addnew(dsos, name);
+ return dso ? dso : __dsos__addnew(dsos, name);
+}
+
+struct dso *dsos__findnew(struct dsos *dsos, const char *name)
+{
+ struct dso *dso;
+ pthread_rwlock_wrlock(&dsos->lock);
+ dso = __dsos__findnew(dsos, name);
+ pthread_rwlock_unlock(&dsos->lock);
+ return dso;
}
size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index ba2d90e..c16ab5d 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -4,6 +4,7 @@
#include <linux/types.h>
#include <linux/rbtree.h>
#include <stdbool.h>
+#include <pthread.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include "map.h"
@@ -124,6 +125,7 @@
struct dsos {
struct list_head head;
struct rb_root root; /* rbtree root sorted by long name */
+ pthread_rwlock_t lock;
};
struct auxtrace_cache;
@@ -297,11 +299,13 @@
struct dso *machine__findnew_kernel(struct machine *machine, const char *name,
const char *short_name, int dso_type);
+void __dsos__add(struct dsos *dsos, struct dso *dso);
void dsos__add(struct dsos *dsos, struct dso *dso);
-struct dso *dsos__addnew(struct dsos *dsos, const char *name);
-struct dso *dsos__find(const struct dsos *dsos, const char *name,
- bool cmp_short);
+struct dso *__dsos__addnew(struct dsos *dsos, const char *name);
+struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short);
+struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short);
struct dso *__dsos__findnew(struct dsos *dsos, const char *name);
+struct dso *dsos__findnew(struct dsos *dsos, const char *name);
bool __dsos__read_build_ids(struct list_head *head, bool with_hits);
size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
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);
}
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
index 2e8f688..c646c74 100644
--- a/tools/perf/util/vdso.c
+++ b/tools/perf/util/vdso.c
@@ -120,14 +120,14 @@
zfree(&machine->vdso_info);
}
-static struct dso *machine__addnew_vdso(struct machine *machine, const char *short_name,
- const char *long_name)
+static struct dso *__machine__addnew_vdso(struct machine *machine, const char *short_name,
+ const char *long_name)
{
struct dso *dso;
dso = dso__new(short_name);
if (dso != NULL) {
- dsos__add(&machine->dsos, dso);
+ __dsos__add(&machine->dsos, dso);
dso__set_long_name(dso, long_name, false);
}
@@ -230,27 +230,31 @@
return vdso_file->temp_file_name;
}
-static struct dso *vdso__findnew_compat(struct machine *machine,
- struct vdso_file *vdso_file)
+static struct dso *__machine__findnew_compat(struct machine *machine,
+ struct vdso_file *vdso_file)
{
const char *file_name;
struct dso *dso;
- dso = dsos__find(&machine->dsos, vdso_file->dso_name, true);
+ pthread_rwlock_wrlock(&machine->dsos.lock);
+ dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
if (dso)
- return dso;
+ goto out_unlock;
file_name = vdso__get_compat_file(vdso_file);
if (!file_name)
- return NULL;
+ goto out_unlock;
- return machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
+ dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
+out_unlock:
+ pthread_rwlock_unlock(&machine->dsos.lock);
+ return dso;
}
-static int machine__findnew_vdso_compat(struct machine *machine,
- struct thread *thread,
- struct vdso_info *vdso_info,
- struct dso **dso)
+static int __machine__findnew_vdso_compat(struct machine *machine,
+ struct thread *thread,
+ struct vdso_info *vdso_info,
+ struct dso **dso)
{
enum dso_type dso_type;
@@ -267,10 +271,10 @@
switch (dso_type) {
case DSO__TYPE_32BIT:
- *dso = vdso__findnew_compat(machine, &vdso_info->vdso32);
+ *dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
return 1;
case DSO__TYPE_X32BIT:
- *dso = vdso__findnew_compat(machine, &vdso_info->vdsox32);
+ *dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
return 1;
case DSO__TYPE_UNKNOWN:
case DSO__TYPE_64BIT:
@@ -285,31 +289,32 @@
struct thread *thread __maybe_unused)
{
struct vdso_info *vdso_info;
- struct dso *dso;
+ struct dso *dso = NULL;
+ pthread_rwlock_wrlock(&machine->dsos.lock);
if (!machine->vdso_info)
machine->vdso_info = vdso_info__new();
vdso_info = machine->vdso_info;
if (!vdso_info)
- return NULL;
+ goto out_unlock;
#if BITS_PER_LONG == 64
- if (machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
- return dso;
+ if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
+ goto out_unlock;
#endif
- dso = dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
+ dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
if (!dso) {
char *file;
file = get_file(&vdso_info->vdso);
- if (!file)
- return NULL;
-
- dso = machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
+ if (file)
+ dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
}
+out_unlock:
+ pthread_rwlock_unlock(&machine->dsos.lock);
return dso;
}