Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit be957c44 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

ring-buffer: move calculation of event length 



The event length is calculated and passed in to rb_reserve_next_event
in two different locations. Having rb_reserve_next_event do the
calculations directly makes only one location to do the change and
causes the calculation to be inlined by gcc.

Before:
   text    data     bss     dec     hex filename
  16538      24      12   16574    40be kernel/trace/ring_buffer.o

After:
   text    data     bss     dec     hex filename
  16490      24      12   16526    408e kernel/trace/ring_buffer.o

[ Impact: smaller more efficient code ]

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 1cd8d735

kernel/trace/ring_buffer.c

+9 −5
Original line number Diff line number Diff line
@@ -367,6 +367,9 @@ static inline int test_time_stamp(u64 delta) 


#define BUF_PAGE_SIZE (PAGE_SIZE - BUF_PAGE_HDR_SIZE)



/* 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;
@@ -1396,6 +1399,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, 
	int commit = 0;

	int nr_loops = 0;



	length = rb_calculate_event_length(length);

 again:

	/*

	 * We allow for interrupts to reenter here and do a trace.
@@ -1552,8 +1556,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length) 
	if (atomic_read(&cpu_buffer->record_disabled))

		goto out;



	length = rb_calculate_event_length(length);

	if (length > BUF_PAGE_SIZE)

	if (length > BUF_MAX_DATA_SIZE)

		goto out;



	event = rb_reserve_next_event(cpu_buffer, length);
@@ -1758,7 +1761,6 @@ int ring_buffer_write(struct ring_buffer *buffer, 
{

	struct ring_buffer_per_cpu *cpu_buffer;

	struct ring_buffer_event *event;

	unsigned long event_length;

	void *body;

	int ret = -EBUSY;

	int cpu, resched;
@@ -1781,8 +1783,10 @@ int ring_buffer_write(struct ring_buffer *buffer, 
	if (atomic_read(&cpu_buffer->record_disabled))

		goto out;



	event_length = rb_calculate_event_length(length);

	event = rb_reserve_next_event(cpu_buffer, event_length);

	if (length > BUF_MAX_DATA_SIZE)

		goto out;



	event = rb_reserve_next_event(cpu_buffer, length);

	if (!event)

		goto out;