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Commit 0574ea42 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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ring-buffer: only periodically call cond_resched to ring-buffer-benchmark 



Calling cond_resched at every iteration of the loop adds a bit of
overhead to the benchmark.

This patch does two things.

1) only calls cond-resched when CONFIG_PREEMPT is not enabled
2) only calls cond-resched after so many traces has been performed.

[ Impact: less overhead to the ring-buffer-benchmark ]

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 65b77242

kernel/trace/ring_buffer_benchmark.c

+9 −2
Original line number Diff line number Diff line
@@ -218,16 +218,23 @@ static void ring_buffer_producer(void) 
		}

		do_gettimeofday(&end_tv);



		if (consumer && !(++cnt % wakeup_interval))

		cnt++;

		if (consumer && !(cnt % wakeup_interval))

			wake_up_process(consumer);



#ifndef CONFIG_PREEMPT

		/*

		 * If we are a non preempt kernel, the 10 second run will

		 * stop everything while it runs. Instead, we will call

		 * cond_resched and also add any time that was lost by a

		 * rescedule.

		 *

		 * Do a cond resched at the same frequency we would wake up

		 * the reader.

		 */

		if (cnt % wakeup_interval)

			cond_resched();

#endif



	} while (end_tv.tv_sec < (start_tv.tv_sec + RUN_TIME) && !kill_test);

	pr_info("End ring buffer hammer\n");