[PATCH v2 02/26] perf thread: Make threads rbtree non-invasive
From: Ian Rogers
Date: Thu Jun 08 2023 - 19:29:36 EST
Separate the rbtree out of thread and into a new struct
thread_rb_node. The refcnt is in thread and the rbtree is responsible
for a single count.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/builtin-report.c | 2 +-
tools/perf/builtin-trace.c | 2 +-
tools/perf/util/machine.c | 101 +++++++++++++++++++++++-------------
tools/perf/util/thread.c | 3 --
tools/perf/util/thread.h | 6 ++-
5 files changed, 73 insertions(+), 41 deletions(-)
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 92c6797e7cba..c7d526283baf 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -911,7 +911,7 @@ static int tasks_print(struct report *rep, FILE *fp)
nd = rb_next(nd)) {
task = tasks + itask++;
- task->thread = rb_entry(nd, struct thread, rb_node);
+ task->thread = rb_entry(nd, struct thread_rb_node, rb_node)->thread;
INIT_LIST_HEAD(&task->children);
INIT_LIST_HEAD(&task->list);
thread__set_priv(task->thread, task);
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 62c7c99a0fe4..b0dd202d14eb 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -4348,7 +4348,7 @@ DEFINE_RESORT_RB(threads, (thread__nr_events(a->thread->priv) < thread__nr_event
struct thread *thread;
)
{
- entry->thread = rb_entry(nd, struct thread, rb_node);
+ entry->thread = rb_entry(nd, struct thread_rb_node, rb_node)->thread;
}
static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index a1954ac85f59..cbf092e32ee9 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -43,7 +43,8 @@
#include <linux/string.h>
#include <linux/zalloc.h>
-static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock);
+static void __machine__remove_thread(struct machine *machine, struct thread_rb_node *nd,
+ struct thread *th, bool lock);
static int append_inlines(struct callchain_cursor *cursor, struct map_symbol *ms, u64 ip);
static struct dso *machine__kernel_dso(struct machine *machine)
@@ -72,6 +73,21 @@ static void machine__threads_init(struct machine *machine)
}
}
+static int thread_rb_node__cmp_tid(const void *key, const struct rb_node *nd)
+{
+ int to_find = (int) *((pid_t *)key);
+
+ return to_find - (int)rb_entry(nd, struct thread_rb_node, rb_node)->thread->tid;
+}
+
+static struct thread_rb_node *thread_rb_node__find(const struct thread *th,
+ struct rb_root *tree)
+{
+ struct rb_node *nd = rb_find(&th->tid, tree, thread_rb_node__cmp_tid);
+
+ return rb_entry(nd, struct thread_rb_node, rb_node);
+}
+
static int machine__set_mmap_name(struct machine *machine)
{
if (machine__is_host(machine))
@@ -214,10 +230,10 @@ void machine__delete_threads(struct machine *machine)
down_write(&threads->lock);
nd = rb_first_cached(&threads->entries);
while (nd) {
- struct thread *t = rb_entry(nd, struct thread, rb_node);
+ struct thread_rb_node *trb = rb_entry(nd, struct thread_rb_node, rb_node);
nd = rb_next(nd);
- __machine__remove_thread(machine, t, false);
+ __machine__remove_thread(machine, trb, trb->thread, false);
}
up_write(&threads->lock);
}
@@ -605,6 +621,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
struct rb_node **p = &threads->entries.rb_root.rb_node;
struct rb_node *parent = NULL;
struct thread *th;
+ struct thread_rb_node *nd;
bool leftmost = true;
th = threads__get_last_match(threads, machine, pid, tid);
@@ -613,7 +630,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
while (*p != NULL) {
parent = *p;
- th = rb_entry(parent, struct thread, rb_node);
+ th = rb_entry(parent, struct thread_rb_node, rb_node)->thread;
if (th->tid == tid) {
threads__set_last_match(threads, th);
@@ -633,30 +650,39 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
return NULL;
th = thread__new(pid, tid);
- if (th != NULL) {
- rb_link_node(&th->rb_node, parent, p);
- rb_insert_color_cached(&th->rb_node, &threads->entries, leftmost);
+ if (th == NULL)
+ return NULL;
- /*
- * We have to initialize maps separately after rb tree is updated.
- *
- * The reason is that we call machine__findnew_thread
- * within thread__init_maps to find the thread
- * leader and that would screwed the rb tree.
- */
- if (thread__init_maps(th, machine)) {
- rb_erase_cached(&th->rb_node, &threads->entries);
- RB_CLEAR_NODE(&th->rb_node);
- thread__put(th);
- return NULL;
- }
- /*
- * It is now in the rbtree, get a ref
- */
- thread__get(th);
- threads__set_last_match(threads, th);
- ++threads->nr;
+ nd = malloc(sizeof(*nd));
+ if (nd == NULL) {
+ thread__put(th);
+ return NULL;
+ }
+ nd->thread = th;
+
+ rb_link_node(&nd->rb_node, parent, p);
+ rb_insert_color_cached(&nd->rb_node, &threads->entries, leftmost);
+
+ /*
+ * We have to initialize maps separately after rb tree is updated.
+ *
+ * The reason is that we call machine__findnew_thread within
+ * thread__init_maps to find the thread leader and that would screwed
+ * the rb tree.
+ */
+ if (thread__init_maps(th, machine)) {
+ rb_erase_cached(&nd->rb_node, &threads->entries);
+ RB_CLEAR_NODE(&nd->rb_node);
+ free(nd);
+ thread__put(th);
+ return NULL;
}
+ /*
+ * It is now in the rbtree, get a ref
+ */
+ thread__get(th);
+ threads__set_last_match(threads, th);
+ ++threads->nr;
return th;
}
@@ -1109,7 +1135,7 @@ size_t machine__fprintf(struct machine *machine, FILE *fp)
for (nd = rb_first_cached(&threads->entries); nd;
nd = rb_next(nd)) {
- struct thread *pos = rb_entry(nd, struct thread, rb_node);
+ struct thread *pos = rb_entry(nd, struct thread_rb_node, rb_node)->thread;
ret += thread__fprintf(pos, fp);
}
@@ -2020,10 +2046,14 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event
return 0;
}
-static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock)
+static void __machine__remove_thread(struct machine *machine, struct thread_rb_node *nd,
+ struct thread *th, bool lock)
{
struct threads *threads = machine__threads(machine, th->tid);
+ if (!nd)
+ nd = thread_rb_node__find(th, &threads->entries.rb_root);
+
if (threads->last_match == th)
threads__set_last_match(threads, NULL);
@@ -2032,11 +2062,12 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
BUG_ON(refcount_read(&th->refcnt) == 0);
- rb_erase_cached(&th->rb_node, &threads->entries);
- RB_CLEAR_NODE(&th->rb_node);
+ thread__put(nd->thread);
+ rb_erase_cached(&nd->rb_node, &threads->entries);
+ RB_CLEAR_NODE(&nd->rb_node);
--threads->nr;
- thread__put(th);
+ free(nd);
if (lock)
up_write(&threads->lock);
@@ -2044,7 +2075,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
void machine__remove_thread(struct machine *machine, struct thread *th)
{
- return __machine__remove_thread(machine, th, true);
+ return __machine__remove_thread(machine, NULL, th, true);
}
int machine__process_fork_event(struct machine *machine, union perf_event *event,
@@ -3167,7 +3198,6 @@ int machine__for_each_thread(struct machine *machine,
{
struct threads *threads;
struct rb_node *nd;
- struct thread *thread;
int rc = 0;
int i;
@@ -3175,8 +3205,9 @@ int machine__for_each_thread(struct machine *machine,
threads = &machine->threads[i];
for (nd = rb_first_cached(&threads->entries); nd;
nd = rb_next(nd)) {
- thread = rb_entry(nd, struct thread, rb_node);
- rc = fn(thread, priv);
+ struct thread_rb_node *trb = rb_entry(nd, struct thread_rb_node, rb_node);
+
+ rc = fn(trb->thread, priv);
if (rc != 0)
return rc;
}
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index d949bffc0ed6..38d300e3e4d3 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -66,7 +66,6 @@ struct thread *thread__new(pid_t pid, pid_t tid)
list_add(&comm->list, &thread->comm_list);
refcount_set(&thread->refcnt, 1);
- RB_CLEAR_NODE(&thread->rb_node);
/* Thread holds first ref to nsdata. */
thread->nsinfo = nsinfo__new(pid);
srccode_state_init(&thread->srccode_state);
@@ -84,8 +83,6 @@ void thread__delete(struct thread *thread)
struct namespaces *namespaces, *tmp_namespaces;
struct comm *comm, *tmp_comm;
- BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
-
thread_stack__free(thread);
if (thread->maps) {
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 86737812e06b..3b3f9fb5a916 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -29,8 +29,12 @@ struct lbr_stitch {
struct callchain_cursor_node *prev_lbr_cursor;
};
+struct thread_rb_node {
+ struct rb_node rb_node;
+ struct thread *thread;
+};
+
struct thread {
- struct rb_node rb_node;
struct maps *maps;
pid_t pid_; /* Not all tools update this */
pid_t tid;
--
2.41.0.162.gfafddb0af9-goog