Commit 75b21c6d authored Jun 30, 2020 by Steven Rostedt (VMware)

ring-buffer: Mark the !tail (crossing a page) as unlikely

It is the uncommon case where an event crosses a sub buffer boundary (page)
mark that check at the end of reserving an event as unlikely.

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent b23d7a5f

kernel/trace/ring_buffer.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3260,7 +3260,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
		* If this is the first commit on the page, then update
		* its timestamp.
		*/
		if (!tail)
		if (unlikely(!tail))
		tail_page->page->time_stamp = info->ts;

		/* account for these added bytes */