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-rw-r--r--kernel/trace/trace_hwlat.c34
1 files changed, 17 insertions, 17 deletions
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index af344a1bf0d0..75fb54a3acb2 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -266,24 +266,13 @@ out:
static struct cpumask save_cpumask;
static bool disable_migrate;
-static void move_to_next_cpu(bool initmask)
+static void move_to_next_cpu(void)
{
- static struct cpumask *current_mask;
+ struct cpumask *current_mask = &save_cpumask;
int next_cpu;
if (disable_migrate)
return;
-
- /* Just pick the first CPU on first iteration */
- if (initmask) {
- current_mask = &save_cpumask;
- get_online_cpus();
- cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask);
- put_online_cpus();
- next_cpu = cpumask_first(current_mask);
- goto set_affinity;
- }
-
/*
* If for some reason the user modifies the CPU affinity
* of this thread, than stop migrating for the duration
@@ -300,7 +289,6 @@ static void move_to_next_cpu(bool initmask)
if (next_cpu >= nr_cpu_ids)
next_cpu = cpumask_first(current_mask);
- set_affinity:
if (next_cpu >= nr_cpu_ids) /* Shouldn't happen! */
goto disable;
@@ -330,12 +318,10 @@ static void move_to_next_cpu(bool initmask)
static int kthread_fn(void *data)
{
u64 interval;
- bool initmask = true;
while (!kthread_should_stop()) {
- move_to_next_cpu(initmask);
- initmask = false;
+ move_to_next_cpu();
local_irq_disable();
get_sample();
@@ -366,13 +352,27 @@ static int kthread_fn(void *data)
*/
static int start_kthread(struct trace_array *tr)
{
+ struct cpumask *current_mask = &save_cpumask;
struct task_struct *kthread;
+ int next_cpu;
+
+ /* Just pick the first CPU on first iteration */
+ current_mask = &save_cpumask;
+ get_online_cpus();
+ cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask);
+ put_online_cpus();
+ next_cpu = cpumask_first(current_mask);
kthread = kthread_create(kthread_fn, NULL, "hwlatd");
if (IS_ERR(kthread)) {
pr_err(BANNER "could not start sampling thread\n");
return -ENOMEM;
}
+
+ cpumask_clear(current_mask);
+ cpumask_set_cpu(next_cpu, current_mask);
+ sched_setaffinity(kthread->pid, current_mask);
+
hwlat_kthread = kthread;
wake_up_process(kthread);