---

yaml
---
r: 257121
b: refs/heads/master
c: 4376cac
h: refs/heads/master
i:
  257119: adf5456
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e4a3f541f0b67fdad98b326c851dfe7f4b6b6dad
+refs/heads/master: 4376cac66778b25e599be3f5d54f33f58ba8ead7

trunk/kernel/trace/ftrace.c

@@ -3318,7 +3318,7 @@ static int ftrace_process_locs(struct module *mod,
 {
 	unsigned long *p;
 	unsigned long addr;
-	unsigned long flags;
+	unsigned long flags = 0; /* Shut up gcc */
 
 	mutex_lock(&ftrace_lock);
 	p = start;
@@ -3336,12 +3336,18 @@ static int ftrace_process_locs(struct module *mod,
 	}
 
 	/*
-	 * Disable interrupts to prevent interrupts from executing
-	 * code that is being modified.
+	 * We only need to disable interrupts on start up
+	 * because we are modifying code that an interrupt
+	 * may execute, and the modification is not atomic.
+	 * But for modules, nothing runs the code we modify
+	 * until we are finished with it, and there's no
+	 * reason to cause large interrupt latencies while we do it.
 	 */
-	local_irq_save(flags);
+	if (!mod)
+		local_irq_save(flags);
 	ftrace_update_code(mod);
-	local_irq_restore(flags);
+	if (!mod)
+		local_irq_restore(flags);
 	mutex_unlock(&ftrace_lock);
 
 	return 0;