tracing: Convert the per CPU "disabled" counter to local from atomic

The per CPU "disabled" counter is used for the latency tracers and stack
tracers to make sure that their accounting isn't messed up by an NMI or
interrupt coming in and affecting the same CPU data. But the counter is an
atomic_t type. As it only needs to synchronize against the current CPU,
switch it over to local_t type.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.394925376@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 40c39e946940..0b6d932a931e 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -123,12 +123,12 @@ static int func_prolog_dec(struct trace_array *tr,
 		return 0;
 
 	*data = per_cpu_ptr(tr->array_buffer.data, cpu);
-	disabled = atomic_inc_return(&(*data)->disabled);
+	disabled = local_inc_return(&(*data)->disabled);
 
 	if (likely(disabled == 1))
 		return 1;
 
-	atomic_dec(&(*data)->disabled);
+	local_dec(&(*data)->disabled);
 
 	return 0;
 }
@@ -152,7 +152,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
 
 	trace_function(tr, ip, parent_ip, trace_ctx, fregs);
 
-	atomic_dec(&data->disabled);
+	local_dec(&data->disabled);
 }
 #endif /* CONFIG_FUNCTION_TRACER */
 
@@ -209,7 +209,7 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
 
 	trace_ctx = tracing_gen_ctx_flags(flags);
 	ret = __trace_graph_entry(tr, trace, trace_ctx);
-	atomic_dec(&data->disabled);
+	local_dec(&data->disabled);
 
 	return ret;
 }
@@ -238,7 +238,7 @@ static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
 
 	trace_ctx = tracing_gen_ctx_flags(flags);
 	__trace_graph_return(tr, trace, trace_ctx, *calltime, rettime);
-	atomic_dec(&data->disabled);
+	local_dec(&data->disabled);
 }
 
 static struct fgraph_ops fgraph_ops = {
@@ -408,10 +408,10 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
 
 	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 
-	if (unlikely(!data) || atomic_read(&data->disabled))
+	if (unlikely(!data) || local_read(&data->disabled))
 		return;
 
-	atomic_inc(&data->disabled);
+	local_inc(&data->disabled);
 
 	data->critical_sequence = max_sequence;
 	data->preempt_timestamp = ftrace_now(cpu);
@@ -421,7 +421,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
 
 	per_cpu(tracing_cpu, cpu) = 1;
 
-	atomic_dec(&data->disabled);
+	local_dec(&data->disabled);
 }
 
 static nokprobe_inline void
@@ -445,16 +445,16 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
 	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 
 	if (unlikely(!data) ||
-	    !data->critical_start || atomic_read(&data->disabled))
+	    !data->critical_start || local_read(&data->disabled))
 		return;
 
-	atomic_inc(&data->disabled);
+	local_inc(&data->disabled);
 
 	trace_ctx = tracing_gen_ctx();
 	__trace_function(tr, ip, parent_ip, trace_ctx);
 	check_critical_timing(tr, data, parent_ip ? : ip, cpu);
 	data->critical_start = 0;
-	atomic_dec(&data->disabled);
+	local_dec(&data->disabled);
 }
 
 /* start and stop critical timings used to for stoppage (in idle) */