[RFC PATCH 09/14] ring_buffer: Initialize completions statically in the benchmark
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STALE4054d
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From: Petr Mladek <pmladek@suse.com>
Date: 2015-07-28 14:42:03
Also in:
linux-mm, lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Revision rfc of 5 in this series.
Revisions (5)
- rfc current
- v3 [diff vs current]
- v4 [diff vs current]
- v5 [diff vs current]
- v6 [diff vs current]
It looks strange to initialize the completions repeatedly. This patch uses static initialization. It simplifies the code and even helps to get rid of two memory barriers. Signed-off-by: Petr Mladek <pmladek@suse.com> --- kernel/trace/ring_buffer_benchmark.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index a1503a027ee2..ccb1a0b95f64 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c@@ -24,8 +24,8 @@ struct rb_page { static int wakeup_interval = 100; static int reader_finish; -static struct completion read_start; -static struct completion read_done; +static DECLARE_COMPLETION(read_start); +static DECLARE_COMPLETION(read_done); static struct ring_buffer *buffer; static struct task_struct *producer;
@@ -270,11 +270,6 @@ static void ring_buffer_producer(void) trace_printk("End ring buffer hammer\n"); if (consumer) { - /* Init both completions here to avoid races */ - init_completion(&read_start); - init_completion(&read_done); - /* the completions must be visible before the finish var */ - smp_wmb(); reader_finish = 1; /* finish var visible before waking up the consumer */ smp_wmb();
@@ -389,13 +384,10 @@ static int ring_buffer_consumer_thread(void *arg) static int ring_buffer_producer_thread(void *arg) { - init_completion(&read_start); - while (!kthread_should_stop() && !kill_test) { ring_buffer_reset(buffer); if (consumer) { - smp_wmb(); wake_up_process(consumer); wait_for_completion(&read_start); }
--
1.8.5.6
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