From 2808e31ec12e5fbe2ae25acc027fcdc67b1fb7f0 Mon Sep 17 00:00:00 2001 From: "Tzvetomir Stoyanov (VMware)" Date: Tue, 19 Dec 2023 13:54:17 -0500 Subject: ring-buffer: Add interface for configuring trace sub buffer size The trace ring buffer sub page size can be configured, per trace instance. A new ftrace file "buffer_subbuf_order" is added to get and set the size of the ring buffer sub page for current trace instance. The size must be an order of system page size, that's why the new interface works with system page order, instead of absolute page size: 0 means the ring buffer sub page is equal to 1 system page and so forth: 0 - 1 system page 1 - 2 system pages 2 - 4 system pages ... The ring buffer sub page size is limited between 1 and 128 system pages. The default value is 1 system page. New ring buffer APIs are introduced: ring_buffer_subbuf_order_set() ring_buffer_subbuf_order_get() ring_buffer_subbuf_size_get() Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-4-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.298324722@goodmis.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Vincent Donnefort Cc: Kent Overstreet Signed-off-by: Tzvetomir Stoyanov (VMware) Signed-off-by: Steven Rostedt (Google) --- include/linux/ring_buffer.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index ce46218ce46d..12573306b889 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -202,6 +202,10 @@ struct trace_seq; int ring_buffer_print_entry_header(struct trace_seq *s); int ring_buffer_print_page_header(struct trace_buffer *buffer, struct trace_seq *s); +int ring_buffer_subbuf_order_get(struct trace_buffer *buffer); +int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order); +int ring_buffer_subbuf_size_get(struct trace_buffer *buffer); + enum ring_buffer_flags { RB_FL_OVERWRITE = 1 << 0, }; -- cgit v1.2.3