3 files changed, 20 insertions, 5 deletions
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index 5927bf0bd92b..b3e8aa9cd011 100644
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -259,7 +259,9 @@ int lock_contention_read(struct lock_contention *con)
 	fd = bpf_map__fd(skel->maps.lock_stat);
 	stack = bpf_map__fd(skel->maps.stacks);
 
-	con->lost = skel->bss->lost;
+	con->fails.task = skel->bss->task_fail;
+	con->fails.stack = skel->bss->stack_fail;
+	con->fails.time = skel->bss->time_fail;
 
 	stack_trace = zalloc(stack_size);
 	if (stack_trace == NULL)
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
index ed9160999c32..3f4ee3992e81 100644
--- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
+++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
@@ -124,7 +124,9 @@ int lock_owner;
 int aggr_mode;
 
 /* error stat */
-int lost;
+int task_fail;
+int stack_fail;
+int time_fail;
 
 static inline int can_record(u64 *ctx)
 {
@@ -283,7 +285,7 @@ int contention_begin(u64 *ctx)
 		bpf_map_update_elem(&tstamp, &pid, &zero, BPF_ANY);
 		pelem = bpf_map_lookup_elem(&tstamp, &pid);
 		if (pelem == NULL) {
-			lost++;
+			__sync_fetch_and_add(&task_fail, 1);
 			return 0;
 		}
 	}
@@ -296,7 +298,7 @@ int contention_begin(u64 *ctx)
 		pelem->stack_id = bpf_get_stackid(ctx, &stacks,
 						  BPF_F_FAST_STACK_CMP | stack_skip);
 		if (pelem->stack_id < 0)
-			lost++;
+			__sync_fetch_and_add(&stack_fail, 1);
 	} else if (aggr_mode == LOCK_AGGR_TASK) {
 		struct task_struct *task;
 
@@ -340,6 +342,11 @@ int contention_end(u64 *ctx)
 		return 0;
 
 	duration = bpf_ktime_get_ns() - pelem->timestamp;
+	if ((__s64)duration < 0) {
+		bpf_map_delete_elem(&tstamp, &pid);
+		__sync_fetch_and_add(&time_fail, 1);
+		return 0;
+	}
 
 	switch (aggr_mode) {
 	case LOCK_AGGR_CALLER:
diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h
index 040b618b2215..10c28302420c 100644
--- a/tools/perf/util/lock-contention.h
+++ b/tools/perf/util/lock-contention.h
@@ -122,14 +122,20 @@ struct evlist;
 struct machine;
 struct target;
 
+struct lock_contention_fails {
+	int task;
+	int stack;
+	int time;
+};
+
 struct lock_contention {
 	struct evlist *evlist;
 	struct target *target;
 	struct machine *machine;
 	struct hlist_head *result;
 	struct lock_filter *filters;
+	struct lock_contention_fails fails;
 	unsigned long map_nr_entries;
-	int lost;
 	int max_stack;
 	int stack_skip;
 	int aggr_mode;