From: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Date: Tue, 3 Nov 2015 21:19:02 +0000 (-0500)
Subject: ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=54ed1444052467044e9e01334ac8123dd6345211;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark

wake_up_process() has a memory barrier before doing anything, thus adding a
memory barrier before calling it is redundant.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---

diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index 9e00fd178226..6df9a83e20d7 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -288,8 +288,6 @@ static void ring_buffer_producer(void)
 		/* the completions must be visible before the finish var */
 		smp_wmb();
 		reader_finish = 1;
-		/* finish var visible before waking up the consumer */
-		smp_wmb();
 		wake_up_process(consumer);
 		wait_for_completion(&read_done);
 	}