1 files changed, 16 insertions, 18 deletions

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 1439064f65d6..b9f96c77527d 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -499,7 +499,6 @@ static void print_osnoise_headers(struct seq_file *s)
 static void
 __trace_osnoise_sample(struct osnoise_sample *sample, struct trace_buffer *buffer)
 {
-	struct trace_event_call *call = &event_osnoise;
 	struct ring_buffer_event *event;
 	struct osnoise_entry *entry;
 
@@ -517,8 +516,7 @@ __trace_osnoise_sample(struct osnoise_sample *sample, struct trace_buffer *buffe
 	entry->softirq_count	= sample->softirq_count;
 	entry->thread_count	= sample->thread_count;
 
-	if (!call_filter_check_discard(call, entry, buffer, event))
-		trace_buffer_unlock_commit_nostack(buffer, event);
+	trace_buffer_unlock_commit_nostack(buffer, event);
 }
 
 /*
@@ -578,7 +576,6 @@ static void print_timerlat_headers(struct seq_file *s)
 static void
 __trace_timerlat_sample(struct timerlat_sample *sample, struct trace_buffer *buffer)
 {
-	struct trace_event_call *call = &event_osnoise;
 	struct ring_buffer_event *event;
 	struct timerlat_entry *entry;
 
@@ -591,8 +588,7 @@ __trace_timerlat_sample(struct timerlat_sample *sample, struct trace_buffer *buf
 	entry->context			= sample->context;
 	entry->timer_latency		= sample->timer_latency;
 
-	if (!call_filter_check_discard(call, entry, buffer, event))
-		trace_buffer_unlock_commit_nostack(buffer, event);
+	trace_buffer_unlock_commit_nostack(buffer, event);
 }
 
 /*
@@ -654,7 +650,6 @@ static void timerlat_save_stack(int skip)
 static void
 __timerlat_dump_stack(struct trace_buffer *buffer, struct trace_stack *fstack, unsigned int size)
 {
-	struct trace_event_call *call = &event_osnoise;
 	struct ring_buffer_event *event;
 	struct stack_entry *entry;
 
@@ -668,8 +663,7 @@ __timerlat_dump_stack(struct trace_buffer *buffer, struct trace_stack *fstack, u
 	memcpy(&entry->caller, fstack->calls, size);
 	entry->size = fstack->nr_entries;
 
-	if (!call_filter_check_discard(call, entry, buffer, event))
-		trace_buffer_unlock_commit_nostack(buffer, event);
+	trace_buffer_unlock_commit_nostack(buffer, event);
 }
 
 /*
@@ -1953,12 +1947,8 @@ static void stop_kthread(unsigned int cpu)
 {
 	struct task_struct *kthread;
 
-	mutex_lock(&interface_lock);
-	kthread = per_cpu(per_cpu_osnoise_var, cpu).kthread;
+	kthread = xchg_relaxed(&(per_cpu(per_cpu_osnoise_var, cpu).kthread), NULL);
 	if (kthread) {
-		per_cpu(per_cpu_osnoise_var, cpu).kthread = NULL;
-		mutex_unlock(&interface_lock);
-
 		if (cpumask_test_and_clear_cpu(cpu, &kthread_cpumask) &&
 		    !WARN_ON(!test_bit(OSN_WORKLOAD, &osnoise_options))) {
 			kthread_stop(kthread);
@@ -1972,7 +1962,6 @@ static void stop_kthread(unsigned int cpu)
 			put_task_struct(kthread);
 		}
 	} else {
-		mutex_unlock(&interface_lock);
 		/* if no workload, just return */
 		if (!test_bit(OSN_WORKLOAD, &osnoise_options)) {
 			/*
@@ -1994,8 +1983,12 @@ static void stop_per_cpu_kthreads(void)
 {
 	int cpu;
 
-	for_each_possible_cpu(cpu)
+	cpus_read_lock();
+
+	for_each_online_cpu(cpu)
 		stop_kthread(cpu);
+
+	cpus_read_unlock();
 }
 
 /*
@@ -2007,6 +2000,10 @@ static int start_kthread(unsigned int cpu)
 	void *main = osnoise_main;
 	char comm[24];
 
+	/* Do not start a new thread if it is already running */
+	if (per_cpu(per_cpu_osnoise_var, cpu).kthread)
+		return 0;
+
 	if (timerlat_enabled()) {
 		snprintf(comm, 24, "timerlat/%d", cpu);
 		main = timerlat_main;
@@ -2061,11 +2058,10 @@ static int start_per_cpu_kthreads(void)
 		if (cpumask_test_and_clear_cpu(cpu, &kthread_cpumask)) {
 			struct task_struct *kthread;
 
-			kthread = per_cpu(per_cpu_osnoise_var, cpu).kthread;
+			kthread = xchg_relaxed(&(per_cpu(per_cpu_osnoise_var, cpu).kthread), NULL);
 			if (!WARN_ON(!kthread))
 				kthread_stop(kthread);
 		}
-		per_cpu(per_cpu_osnoise_var, cpu).kthread = NULL;
 	}
 
 	for_each_cpu(cpu, current_mask) {
@@ -2095,6 +2091,8 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy)
 	mutex_lock(&interface_lock);
 	cpus_read_lock();
 
+	if (!cpu_online(cpu))
+		goto out_unlock;
 	if (!cpumask_test_cpu(cpu, &osnoise_cpumask))
 		goto out_unlock;