ring-buffer: make use of the helper function kthread_run_on_cpu()

Replace kthread_create/kthread_bind/wake_up_process() with
kthread_run_on_cpu() to simplify the code.

Link: https://lkml.kernel.org/r/20211022025711.3673-4-caihuoqing@baidu.comSigned-off-by: Cai Huoqing <caihuoqing@baidu.com>
Cc: Bernard Metzler <bmt@zurich.ibm.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/trace/ring_buffer.c

@@ -5898,16 +5898,13 @@ static __init int test_ringbuffer(void)
 		rb_data[cpu].buffer = buffer;
 		rb_data[cpu].cpu = cpu;
 		rb_data[cpu].cnt = cpu;
-		rb_threads[cpu] = kthread_create(rb_test, &rb_data[cpu],
-						 "rbtester/%d", cpu);
+		rb_threads[cpu] = kthread_run_on_cpu(rb_test, &rb_data[cpu],
+						     cpu, "rbtester/%u");
 		if (WARN_ON(IS_ERR(rb_threads[cpu]))) {
 			pr_cont("FAILED\n");
 			ret = PTR_ERR(rb_threads[cpu]);
 			goto out_free;
 		}
-
-		kthread_bind(rb_threads[cpu], cpu);
- 		wake_up_process(rb_threads[cpu]);
 	}
 
 	/* Now create the rb hammer! */