[PATCH 4/4] perf lock contention: Show lock type with address

Namhyung Kim
2023-03-13T20:49:06Z

Show lock type names after the symbol of locks if any. This can be
useful especially when it doesn't show the lock symbols.

The indentation before the lock type parenthesis is to recognize lock
symbols more easily.

$ sudo ./perf lock con -abl -- sleep 1
contended total wait max wait avg wait address symbol

44 6.13 ms 284.49 us 139.28 us ffffffff92e06080 tasklist_lock (rwlock)
159 983.38 us 12.38 us 6.18 us ffff8cc717c90000 siglock (spinlock)
10 679.90 us 153.35 us 67.99 us ffff8cdc2872aaf8 mmap_lock (rwsem)
9 558.11 us 180.67 us 62.01 us ffff8cd647914038 mmap_lock (rwsem)
78 228.56 us 7.82 us 2.93 us ffff8cc700061c00 (spinlock)
5 41.60 us 16.93 us 8.32 us ffffd853acb41468 (spinlock)
10 37.24 us 5.87 us 3.72 us ffff8cd560b5c200 siglock (spinlock)
4 11.17 us 3.97 us 2.79 us ffff8d053ddf0c80 rq_lock (spinlock)
1 7.86 us 7.86 us 7.86 us ffff8cd64791404c (spinlock)
1 4.13 us 4.13 us 4.13 us ffff8d053d930c80 rq_lock (spinlock)
7 3.98 us 1.67 us 568 ns ffff8ccb92479440 (mutex)
2 2.62 us 2.33 us 1.31 us ffff8cc702e6ede0 (rwlock)

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/builtin-lock.c | 45 ++++++++++++++++++----------
tools/perf/util/bpf_skel/lock_data.h | 2 ++
2 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index c710a5d46638..a845c0ce5dc8 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -1548,27 +1548,41 @@ static void sort_result(void)

static const struct {
unsigned int flags;
+ const char *str;
const char *name;
} lock_type_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" },
+ { 0, "semaphore", "semaphore" },
+ { LCB_F_SPIN, "spinlock", "spinlock" },
+ { LCB_F_SPIN | LCB_F_READ, "rwlock:R", "rwlock" },
+ { LCB_F_SPIN | LCB_F_WRITE, "rwlock:W", "rwlock" },
+ { LCB_F_READ, "rwsem:R", "rwsem" },
+ { LCB_F_WRITE, "rwsem:W", "rwsem" },
+ { LCB_F_RT, "rt=mutex", "rt-mutex" },
+ { LCB_F_RT | LCB_F_READ, "rwlock-rt:R", "rwlock-rt" },
+ { LCB_F_RT | LCB_F_WRITE, "rwlock-rt:W", "rwlock-rt" },
+ { LCB_F_PERCPU | LCB_F_READ, "pcpu-sem:R", "percpu-rwsem" },
+ { LCB_F_PERCPU | LCB_F_WRITE, "pcpu-sem:W", "percpu-rwsem" },
+ { LCB_F_MUTEX, "mutex", "mutex" },
+ { LCB_F_MUTEX | LCB_F_SPIN, "mutex", "mutex" },
/* alias for get_type_flag() */
- { LCB_F_MUTEX | LCB_F_SPIN, "mutex-spin" },
+ { LCB_F_MUTEX | LCB_F_SPIN, "mutex-spin", "mutex" },
};

static const char *get_type_str(unsigned int flags)
{
+ flags &= LCB_F_MAX_FLAGS - 1;
+
+ for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
+ if (lock_type_table[i].flags == flags)
+ return lock_type_table[i].str;
+ }
+ return "unknown";
+}
+
+static const char *get_type_name(unsigned int flags)
+{
+ flags &= LCB_F_MAX_FLAGS - 1;
+
for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
if (lock_type_table[i].flags == flags)
return lock_type_table[i].name;
@@ -1662,7 +1676,8 @@ static void print_contention_result(struct lock_contention *con)
pid, pid == -1 ? "Unknown" : thread__comm_str(t));
break;
case LOCK_AGGR_ADDR:
- pr_info(" %016llx %s\n", (unsigned long long)st->addr, st->name);
+ pr_info(" %016llx %s (%s)\n", (unsigned long long)st->addr,
+ st->name, get_type_name(st->flags));
break;
default:
break;
diff --git a/tools/perf/util/bpf_skel/lock_data.h b/tools/perf/util/bpf_skel/lock_data.h
index e59366f2dba3..1ba61cb4d480 100644
--- a/tools/perf/util/bpf_skel/lock_data.h
+++ b/tools/perf/util/bpf_skel/lock_data.h
@@ -22,6 +22,8 @@ struct contention_task_data {
#define LCD_F_MMAP_LOCK (1U << 31)
#define LCD_F_SIGHAND_LOCK (1U << 30)

+#define LCB_F_MAX_FLAGS (1U << 7)
+
struct contention_data {
u64 total_time;
u64 min_time;
--
2.40.0.rc1.284.g88254d51c5-goog