perf lock: Introduce struct lock_contention

The lock_contention struct is to carry related fields together and to
minimize the change when we add new config options.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220802191004.347740-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-lock.c

@@ -1595,7 +1595,10 @@ static int __cmd_contention(int argc, const char **argv)
 		.mode  = PERF_DATA_MODE_READ,
 		.force = force,
 	};
-	struct evlist *evlist = NULL;
+	struct lock_contention con = {
+		.target = &target,
+		.result = &lockhash_table[0],
+	};
 
 	session = perf_session__new(use_bpf ? NULL : &data, &eops);
 	if (IS_ERR(session)) {
@@ -1621,24 +1624,26 @@ static int __cmd_contention(int argc, const char **argv)
 		signal(SIGCHLD, sighandler);
 		signal(SIGTERM, sighandler);
 
-		evlist = evlist__new();
-		if (evlist == NULL) {
+		con.machine = &session->machines.host;
+
+		con.evlist = evlist__new();
+		if (con.evlist == NULL) {
 			err = -ENOMEM;
 			goto out_delete;
 		}
 
-		err = evlist__create_maps(evlist, &target);
+		err = evlist__create_maps(con.evlist, &target);
 		if (err < 0)
 			goto out_delete;
 
 		if (argc) {
-			err = evlist__prepare_workload(evlist, &target,
+			err = evlist__prepare_workload(con.evlist, &target,
 						       argv, false, NULL);
 			if (err < 0)
 				goto out_delete;
 		}
 
-		if (lock_contention_prepare(evlist, &target) < 0) {
+		if (lock_contention_prepare(&con) < 0) {
 			pr_err("lock contention BPF setup failed\n");
 			goto out_delete;
 		}
@@ -1673,13 +1678,13 @@ static int __cmd_contention(int argc, const char **argv)
 	if (use_bpf) {
 		lock_contention_start();
 		if (argc)
-			evlist__start_workload(evlist);
+			evlist__start_workload(con.evlist);
 
 		/* wait for signal */
 		pause();
 
 		lock_contention_stop();
-		lock_contention_read(&session->machines.host, &lockhash_table[0]);
+		lock_contention_read(&con);
 	} else {
 		err = perf_session__process_events(session);
 		if (err)
@@ -1692,7 +1697,7 @@ static int __cmd_contention(int argc, const char **argv)
 	print_contention_result();
 
 out_delete:
-	evlist__delete(evlist);
+	evlist__delete(con.evlist);
 	lock_contention_finish();
 	perf_session__delete(session);
 	return err;

tools/perf/util/bpf_lock_contention.c

@@ -27,10 +27,12 @@ struct lock_contention_data {
 	u32 flags;
 };
 
-int lock_contention_prepare(struct evlist *evlist, struct target *target)
+int lock_contention_prepare(struct lock_contention *con)
 {
 	int i, fd;
 	int ncpus = 1, ntasks = 1;
+	struct evlist *evlist = con->evlist;
+	struct target *target = con->target;
 
 	skel = lock_contention_bpf__open();
 	if (!skel) {
@@ -102,12 +104,13 @@ int lock_contention_stop(void)
 	return 0;
 }
 
-int lock_contention_read(struct machine *machine, struct hlist_head *head)
+int lock_contention_read(struct lock_contention *con)
 {
 	int fd, stack;
 	u32 prev_key, key;
 	struct lock_contention_data data;
 	struct lock_stat *st;
+	struct machine *machine = con->machine;
 	u64 stack_trace[CONTENTION_STACK_DEPTH];
 
 	fd = bpf_map__fd(skel->maps.lock_stat);
@@ -163,7 +166,7 @@ int lock_contention_read(struct machine *machine, struct hlist_head *head)
 			return -1;
 		}
 
-		hlist_add_head(&st->hash_entry, head);
+		hlist_add_head(&st->hash_entry, con->result);
 		prev_key = key;
 	}
 

tools/perf/util/lock-contention.h

@@ -107,18 +107,24 @@ struct evlist;
 struct machine;
 struct target;
 
+struct lock_contention {
+	struct evlist *evlist;
+	struct target *target;
+	struct machine *machine;
+	struct hlist_head *result;
+};
+
 #ifdef HAVE_BPF_SKEL
 
-int lock_contention_prepare(struct evlist *evlist, struct target *target);
+int lock_contention_prepare(struct lock_contention *con);
 int lock_contention_start(void);
 int lock_contention_stop(void);
-int lock_contention_read(struct machine *machine, struct hlist_head *head);
+int lock_contention_read(struct lock_contention *con);
 int lock_contention_finish(void);
 
 #else  /* !HAVE_BPF_SKEL */
 
-static inline int lock_contention_prepare(struct evlist *evlist __maybe_unused,
-					  struct target *target __maybe_unused)
+static inline int lock_contention_prepare(struct lock_contention *con __maybe_unused)
 {
 	return 0;
 }
@@ -127,8 +133,7 @@ static inline int lock_contention_start(void) { return 0; }
 static inline int lock_contention_stop(void) { return 0; }
 static inline int lock_contention_finish(void) { return 0; }
 
-static inline int lock_contention_read(struct machine *machine __maybe_unused,
-				       struct hlist_head *head __maybe_unused)
+static inline int lock_contention_read(struct lock_contention *con __maybe_unused)
 {
 	return 0;
 }