# \[PATCH\] ring-buffer: Fix bytes\_dropped calculation issue

- From: Feng Yang \<hidden\>
- Date: 2025-02-23 07:01:32 
- List: linux-trace-kernel
- Page: https://ratatoskr.run/linux-trace-kernel/2025/02/2939486
- Thread: https://ratatoskr.run/linux-trace-kernel/2025/02/2939486/t.md

```text
From: Feng Yang <redacted>

The calculation of bytes-dropped and bytes_dropped_nested is reversed.
Although it does not affect the final calculation of total_dropped,
it should still be modified.

Fixes: 6c43e554a2a5 ("ring-buffer: Add ring buffer startup selftest")
Signed-off-by: Feng Yang <redacted>
---
 kernel/trace/ring_buffer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index bb6089c2951e..510409f97992 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -7411,9 +7411,9 @@ static __init int rb_write_something(struct rb_test_data *data, bool nested)
 		/* Ignore dropped events before test starts. */
 		if (started) {
 			if (nested)
-				data->bytes_dropped += len;
-			else
 				data->bytes_dropped_nested += len;
+			else
+				data->bytes_dropped += len;
 		}
 		return len;
 	}
-- 
2.39.0.windows.2

```