Merge branch '5.15-2.2.x-imx' into toradex_5.15-2.2.x-imxtoradex_5.15-2.2.x-imx

Conflicts:
	drivers/tty/serial/fsl_lpuart.c

Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>

1 files changed, 13 insertions, 15 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 6ec08eca7f4b..d91a673ffc3e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -510,6 +510,7 @@ static int function_stat_show(struct seq_file *m, void *v)
 	static struct trace_seq s;
 	unsigned long long avg;
 	unsigned long long stddev;
+	unsigned long long stddev_denom;
 #endif
 	mutex_lock(&ftrace_profile_lock);
 
@@ -531,23 +532,19 @@ static int function_stat_show(struct seq_file *m, void *v)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	seq_puts(m, "    ");
 
-	/* Sample standard deviation (s^2) */
-	if (rec->counter <= 1)
-		stddev = 0;
-	else {
-		/*
-		 * Apply Welford's method:
-		 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
-		 */
+	/*
+	 * Variance formula:
+	 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
+	 * Maybe Welford's method is better here?
+	 * Divide only by 1000 for ns^2 -> us^2 conversion.
+	 * trace_print_graph_duration will divide by 1000 again.
+	 */
+	stddev = 0;
+	stddev_denom = rec->counter * (rec->counter - 1) * 1000;
+	if (stddev_denom) {
 		stddev = rec->counter * rec->time_squared -
 			 rec->time * rec->time;
-
-		/*
-		 * Divide only 1000 for ns^2 -> us^2 conversion.
-		 * trace_print_graph_duration will divide 1000 again.
-		 */
-		stddev = div64_ul(stddev,
-				  rec->counter * (rec->counter - 1) * 1000);
+		stddev = div64_ul(stddev, stddev_denom);
 	}
 
 	trace_seq_init(&s);
@@ -6093,6 +6090,7 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
 				}
 			}
 		}
+		cond_resched();
 	} while_for_each_ftrace_rec();
 out:
 	mutex_unlock(&ftrace_lock);