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Commit f6195aa0 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

ring-buffer: Place duplicate expression into a single function 



While discussing the strictness of the 80 character limit on the
Kernel Summit Discussion mailing list, I showed examples that I
broke that limit slightly with some algorithms. In discussing with
John Linville, what looked better, I realized that two of the
80 char breaking culprits were an identical expression.

As a clean up, this patch moves the identical expression into its
own helper function and that is used instead. As a side effect,
the offending code is now under the 80 character limit. :-)

This clean up code also changes the expression from

	(A - B) - C  to  A - (B + C)

This makes the code look a little nicer too.

Cc: John W. Linville <linville@tuxdriver.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent c9cf4a01

kernel/trace/ring_buffer.c

+15 −6
Original line number Diff line number Diff line
@@ -2606,6 +2606,19 @@ void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu) 
}

EXPORT_SYMBOL_GPL(ring_buffer_record_enable_cpu);



/*

 * The total entries in the ring buffer is the running counter

 * of entries entered into the ring buffer, minus the sum of

 * the entries read from the ring buffer and the number of

 * entries that were overwritten.

 */

static inline unsigned long

rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer)

{

	return local_read(&cpu_buffer->entries) -

		(local_read(&cpu_buffer->overrun) + cpu_buffer->read);

}



/**

 * ring_buffer_entries_cpu - get the number of entries in a cpu buffer

 * @buffer: The ring buffer
@@ -2614,16 +2627,13 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable_cpu); 
unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)

{

	struct ring_buffer_per_cpu *cpu_buffer;

	unsigned long ret;



	if (!cpumask_test_cpu(cpu, buffer->cpumask))

		return 0;



	cpu_buffer = buffer->buffers[cpu];

	ret = (local_read(&cpu_buffer->entries) - local_read(&cpu_buffer->overrun))

		- cpu_buffer->read;



	return ret;

	return rb_num_of_entries(cpu_buffer);

}

EXPORT_SYMBOL_GPL(ring_buffer_entries_cpu);
@@ -2684,8 +2694,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer) 
	/* if you care about this being correct, lock the buffer */

	for_each_buffer_cpu(buffer, cpu) {

		cpu_buffer = buffer->buffers[cpu];

		entries += (local_read(&cpu_buffer->entries) -

			    local_read(&cpu_buffer->overrun)) - cpu_buffer->read;

		entries += rb_num_of_entries(cpu_buffer);

	}



	return entries;