Like in the software events, the BPF overflow handler can drop samples
by returning 0. Let's count the dropped samples here too.
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Cc: Kyle Huey <me@xxxxxxxxxxxx>
Cc: bpf@xxxxxxxxxxxxxxx
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
kernel/events/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8250e76f63358689..ba1f6b51ea26db5b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9808,8 +9808,10 @@ static int __perf_event_overflow(struct perf_event *event,
ret = __perf_event_account_interrupt(event, throttle);
- if (event->prog && !bpf_overflow_handler(event, data, regs))
+ if (event->prog && !bpf_overflow_handler(event, data, regs)) {
+ atomic64_inc(&event->dropped_samples);
return ret;
+ }
/*
* XXX event_limit might not quite work as expected on inherited
--
2.46.0.469.g59c65b2a67-goog
