From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

In addition to the index number, show the commit numbers of
each data page in per_cpu buffer_meta file.
This is useful for understanding the current status of the
persistent ring buffer. (Note that this file is shown
only for persistent ring buffer and its backup instance)

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/ring_buffer.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index fb098b0b4505..5b40fea6b15d 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2209,6 +2209,7 @@ static int rbm_show(struct seq_file *m, void *v)
 	struct ring_buffer_per_cpu *cpu_buffer = m->private;
 	struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta;
 	unsigned long val = (unsigned long)v;
+	struct buffer_data_page *dpage;
 
 	if (val == 1) {
 		seq_printf(m, "head_buffer:   %d\n",
@@ -2221,7 +2222,9 @@ static int rbm_show(struct seq_file *m, void *v)
 	}
 
 	val -= 2;
-	seq_printf(m, "buffer[%ld]:    %d\n", val, meta->buffers[val]);
+	dpage = rb_range_buffer(cpu_buffer, val);
+	seq_printf(m, "buffer[%ld]:    %d (commit: %ld)\n",
+		   val, meta->buffers[val], local_read(&dpage->commit));
 
 	return 0;
 }