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-rw-r--r--tools/perf/Documentation/perf-lock.txt4
-rw-r--r--tools/perf/builtin-lock.c212
2 files changed, 214 insertions, 2 deletions
diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt
index 4b8568f0c53b..da0bcbc676a3 100644
--- a/tools/perf/Documentation/perf-lock.txt
+++ b/tools/perf/Documentation/perf-lock.txt
@@ -8,7 +8,7 @@ perf-lock - Analyze lock events
SYNOPSIS
--------
[verse]
-'perf lock' {record|report|script|info}
+'perf lock' {record|report|script|info|contention}
DESCRIPTION
-----------
@@ -27,6 +27,8 @@ and statistics with this 'perf lock' command.
'perf lock info' shows metadata like threads or addresses
of lock instances.
+ 'perf lock contention' shows contention statistics.
+
COMMON OPTIONS
--------------
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index b4e7a6e5c54e..64f635273660 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -145,6 +145,18 @@ static enum {
*/
#define CONTENTION_STACK_SKIP 3
+/*
+ * flags for lock:contention_begin
+ * Imported from include/trace/events/lock.h.
+ */
+#define LCB_F_SPIN (1U << 0)
+#define LCB_F_READ (1U << 1)
+#define LCB_F_WRITE (1U << 2)
+#define LCB_F_RT (1U << 3)
+#define LCB_F_PERCPU (1U << 4)
+#define LCB_F_MUTEX (1U << 5)
+
+
static u64 sched_text_start;
static u64 sched_text_end;
static u64 lock_text_start;
@@ -1022,6 +1034,51 @@ next:
return -1;
}
+static u64 callchain_id(struct evsel *evsel, struct perf_sample *sample)
+{
+ struct callchain_cursor *cursor = &callchain_cursor;
+ struct thread *thread;
+ u64 hash = 0;
+ int skip = 0;
+ int ret;
+
+ thread = machine__findnew_thread(&session->machines.host,
+ -1, sample->pid);
+ if (thread == NULL)
+ return -1;
+
+ /* use caller function name from the callchain */
+ ret = thread__resolve_callchain(thread, cursor, evsel, sample,
+ NULL, NULL, CONTENTION_STACK_DEPTH);
+ thread__put(thread);
+
+ if (ret != 0)
+ return -1;
+
+ callchain_cursor_commit(cursor);
+
+ while (true) {
+ struct callchain_cursor_node *node;
+
+ node = callchain_cursor_current(cursor);
+ if (node == NULL)
+ break;
+
+ /* skip first few entries - for lock functions */
+ if (++skip <= CONTENTION_STACK_SKIP)
+ goto next;
+
+ if (node->ms.sym && is_lock_function(node->ip))
+ goto next;
+
+ hash ^= hash_long((unsigned long)node->ip, 64);
+
+next:
+ callchain_cursor_advance(cursor);
+ }
+ return hash;
+}
+
static int report_lock_contention_begin_event(struct evsel *evsel,
struct perf_sample *sample)
{
@@ -1039,6 +1096,8 @@ static int report_lock_contention_begin_event(struct evsel *evsel,
key = sample->tid;
break;
case LOCK_AGGR_CALLER:
+ key = callchain_id(evsel, sample);
+ break;
default:
pr_err("Invalid aggregation mode: %d\n", aggr_mode);
return -EINVAL;
@@ -1120,6 +1179,8 @@ static int report_lock_contention_end_event(struct evsel *evsel,
key = sample->tid;
break;
case LOCK_AGGR_CALLER:
+ key = callchain_id(evsel, sample);
+ break;
default:
pr_err("Invalid aggregation mode: %d\n", aggr_mode);
return -EINVAL;
@@ -1183,6 +1244,12 @@ static struct trace_lock_handler report_lock_ops = {
.contention_end_event = report_lock_contention_end_event,
};
+static struct trace_lock_handler contention_lock_ops = {
+ .contention_begin_event = report_lock_contention_begin_event,
+ .contention_end_event = report_lock_contention_end_event,
+};
+
+
static struct trace_lock_handler *trace_handler;
static int evsel__process_lock_acquire(struct evsel *evsel, struct perf_sample *sample)
@@ -1428,6 +1495,67 @@ static void sort_result(void)
}
}
+static const char *get_type_str(struct lock_stat *st)
+{
+ static const struct {
+ unsigned int flags;
+ const char *name;
+ } table[] = {
+ { 0, "semaphore" },
+ { LCB_F_SPIN, "spinlock" },
+ { LCB_F_SPIN | LCB_F_READ, "rwlock:R" },
+ { LCB_F_SPIN | LCB_F_WRITE, "rwlock:W"},
+ { LCB_F_READ, "rwsem:R" },
+ { LCB_F_WRITE, "rwsem:W" },
+ { LCB_F_RT, "rtmutex" },
+ { LCB_F_RT | LCB_F_READ, "rwlock-rt:R" },
+ { LCB_F_RT | LCB_F_WRITE, "rwlock-rt:W"},
+ { LCB_F_PERCPU | LCB_F_READ, "pcpu-sem:R" },
+ { LCB_F_PERCPU | LCB_F_WRITE, "pcpu-sem:W" },
+ { LCB_F_MUTEX, "mutex" },
+ { LCB_F_MUTEX | LCB_F_SPIN, "mutex" },
+ };
+
+ for (unsigned int i = 0; i < ARRAY_SIZE(table); i++) {
+ if (table[i].flags == st->flags)
+ return table[i].name;
+ }
+ return "unknown";
+}
+
+static void sort_contention_result(void)
+{
+ sort_result();
+}
+
+static void print_contention_result(void)
+{
+ struct lock_stat *st;
+ struct lock_key *key;
+ int bad, total;
+
+ list_for_each_entry(key, &lock_keys, list)
+ pr_info("%*s ", key->len, key->header);
+
+ pr_info(" %10s %s\n\n", "type", "caller");
+
+ bad = total = 0;
+ while ((st = pop_from_result())) {
+ total++;
+ if (st->broken)
+ bad++;
+
+ list_for_each_entry(key, &lock_keys, list) {
+ key->print(key, st);
+ pr_info(" ");
+ }
+
+ pr_info(" %10s %s\n", get_type_str(st), st->name);
+ }
+
+ print_bad_events(bad, total);
+}
+
static const struct evsel_str_handler lock_tracepoints[] = {
{ "lock:lock_acquire", evsel__process_lock_acquire, }, /* CONFIG_LOCKDEP */
{ "lock:lock_acquired", evsel__process_lock_acquired, }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */
@@ -1508,6 +1636,68 @@ out_delete:
return err;
}
+static int __cmd_contention(void)
+{
+ int err = -EINVAL;
+ struct perf_tool eops = {
+ .sample = process_sample_event,
+ .comm = perf_event__process_comm,
+ .mmap = perf_event__process_mmap,
+ .ordered_events = true,
+ };
+ struct perf_data data = {
+ .path = input_name,
+ .mode = PERF_DATA_MODE_READ,
+ .force = force,
+ };
+
+ session = perf_session__new(&data, &eops);
+ if (IS_ERR(session)) {
+ pr_err("Initializing perf session failed\n");
+ return PTR_ERR(session);
+ }
+
+ /* for lock function check */
+ symbol_conf.sort_by_name = true;
+ symbol__init(&session->header.env);
+
+ if (!perf_session__has_traces(session, "lock record"))
+ goto out_delete;
+
+ if (!evlist__find_evsel_by_str(session->evlist, "lock:contention_begin")) {
+ pr_err("lock contention evsel not found\n");
+ goto out_delete;
+ }
+
+ if (perf_session__set_tracepoints_handlers(session, contention_tracepoints)) {
+ pr_err("Initializing perf session tracepoint handlers failed\n");
+ goto out_delete;
+ }
+
+ if (setup_output_field("contended,wait_total,wait_max,avg_wait"))
+ goto out_delete;
+
+ sort_key = "wait_total";
+ if (select_key())
+ goto out_delete;
+
+ aggr_mode = LOCK_AGGR_CALLER;
+
+ err = perf_session__process_events(session);
+ if (err)
+ goto out_delete;
+
+ setup_pager();
+
+ sort_contention_result();
+ print_contention_result();
+
+out_delete:
+ perf_session__delete(session);
+ return err;
+}
+
+
static int __cmd_record(int argc, const char **argv)
{
const char *record_args[] = {
@@ -1626,12 +1816,17 @@ int cmd_lock(int argc, const char **argv)
OPT_PARENT(lock_options)
};
+ const struct option contention_options[] = {
+ OPT_PARENT(lock_options)
+ };
+
const char * const info_usage[] = {
"perf lock info [<options>]",
NULL
};
const char *const lock_subcommands[] = { "record", "report", "script",
- "info", NULL };
+ "info", "contention",
+ "contention", NULL };
const char *lock_usage[] = {
NULL,
NULL
@@ -1640,6 +1835,10 @@ int cmd_lock(int argc, const char **argv)
"perf lock report [<options>]",
NULL
};
+ const char * const contention_usage[] = {
+ "perf lock contention [<options>]",
+ NULL
+ };
unsigned int i;
int rc = 0;
@@ -1675,6 +1874,17 @@ int cmd_lock(int argc, const char **argv)
/* recycling report_lock_ops */
trace_handler = &report_lock_ops;
rc = __cmd_report(true);
+ } else if (strlen(argv[0]) > 2 && strstarts("contention", argv[0])) {
+ trace_handler = &contention_lock_ops;
+ if (argc) {
+ argc = parse_options(argc, argv, contention_options,
+ contention_usage, 0);
+ if (argc) {
+ usage_with_options(contention_usage,
+ contention_options);
+ }
+ }
+ rc = __cmd_contention();
} else {
usage_with_options(lock_usage, lock_options);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.