[PATCH v4 01/15] ring-buffer: Refactor ring buffer implementation

From: Steven Rostedt
Date: Fri Dec 15 2023 - 12:55:23 EST


From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx>

In order to introduce sub-buffer size per ring buffer, some internal
refactoring is needed. As ring_buffer_print_page_header() will depend on
the trace_buffer structure, it is moved after the structure definition.

Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-2-tz.stoyanov@xxxxxxxxx

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ring_buffer.c | 60 +++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 47f9eda99769..196e3f284723 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -378,36 +378,6 @@ static inline bool test_time_stamp(u64 delta)
/* Max payload is BUF_PAGE_SIZE - header (8bytes) */
#define BUF_MAX_DATA_SIZE (BUF_PAGE_SIZE - (sizeof(u32) * 2))

-int ring_buffer_print_page_header(struct trace_seq *s)
-{
- struct buffer_data_page field;
-
- trace_seq_printf(s, "\tfield: u64 timestamp;\t"
- "offset:0;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)sizeof(field.time_stamp),
- (unsigned int)is_signed_type(u64));
-
- trace_seq_printf(s, "\tfield: local_t commit;\t"
- "offset:%u;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)offsetof(typeof(field), commit),
- (unsigned int)sizeof(field.commit),
- (unsigned int)is_signed_type(long));
-
- trace_seq_printf(s, "\tfield: int overwrite;\t"
- "offset:%u;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)offsetof(typeof(field), commit),
- 1,
- (unsigned int)is_signed_type(long));
-
- trace_seq_printf(s, "\tfield: char data;\t"
- "offset:%u;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)offsetof(typeof(field), data),
- (unsigned int)BUF_PAGE_SIZE,
- (unsigned int)is_signed_type(char));
-
- return !trace_seq_has_overflowed(s);
-}
-
struct rb_irq_work {
struct irq_work work;
wait_queue_head_t waiters;
@@ -555,6 +525,36 @@ struct ring_buffer_iter {
int missed_events;
};

+int ring_buffer_print_page_header(struct trace_seq *s)
+{
+ struct buffer_data_page field;
+
+ trace_seq_printf(s, "\tfield: u64 timestamp;\t"
+ "offset:0;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)sizeof(field.time_stamp),
+ (unsigned int)is_signed_type(u64));
+
+ trace_seq_printf(s, "\tfield: local_t commit;\t"
+ "offset:%u;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)offsetof(typeof(field), commit),
+ (unsigned int)sizeof(field.commit),
+ (unsigned int)is_signed_type(long));
+
+ trace_seq_printf(s, "\tfield: int overwrite;\t"
+ "offset:%u;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)offsetof(typeof(field), commit),
+ 1,
+ (unsigned int)is_signed_type(long));
+
+ trace_seq_printf(s, "\tfield: char data;\t"
+ "offset:%u;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)offsetof(typeof(field), data),
+ (unsigned int)BUF_PAGE_SIZE,
+ (unsigned int)is_signed_type(char));
+
+ return !trace_seq_has_overflowed(s);
+}
+
static inline void rb_time_read(rb_time_t *t, u64 *ret)
{
*ret = local64_read(&t->time);
--
2.42.0