[006/146] trace/hwlat: make use of the helper function kthread_run_on_cpu()

Commit Message

Andrew Morton Jan. 14, 2022, 10:03 p.m. UTC

From: Cai Huoqing <[e-mail]>
Subject: trace/hwlat: make use of the helper function kthread_run_on_cpu()

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

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Cai Huoqing <[e-mail]>
Cc: Bernard Metzler <[e-mail]>
Cc: Daniel Bristot de Oliveira <[e-mail]>
Cc: Davidlohr Bueso <[e-mail]>
Cc: Doug Ledford <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jason Gunthorpe <[e-mail]>
Cc: Joel Fernandes (Google) <[e-mail]>
Cc: Josh Triplett <[e-mail]>
Cc: Lai Jiangshan <[e-mail]>
Cc: Mathieu Desnoyers <[e-mail]>
Cc: "Paul E . McKenney" <[e-mail]>
Cc: Steven Rostedt <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 kernel/trace/trace_hwlat.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

Patch

--- a/kernel/trace/trace_hwlat.c~trace-hwlat-make-use-of-the-helper-function-kthread_run_on_cpu
+++ a/kernel/trace/trace_hwlat.c
@@ -491,18 +491,14 @@  static void stop_per_cpu_kthreads(void)
 static int start_cpu_kthread(unsigned int cpu)
 {
 	struct task_struct *kthread;
-	char comm[24];
 
-	snprintf(comm, 24, "hwlatd/%d", cpu);
-
-	kthread = kthread_create_on_cpu(kthread_fn, NULL, cpu, comm);
+	kthread = kthread_run_on_cpu(kthread_fn, NULL, cpu, "hwlatd/%u");
 	if (IS_ERR(kthread)) {
 		pr_err(BANNER "could not start sampling thread\n");
 		return -ENOMEM;
 	}
 
 	per_cpu(hwlat_per_cpu_data, cpu).kthread = kthread;
-	wake_up_process(kthread);
 
 	return 0;
 }