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Merge tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlet from Steven Rostedt:
 "Remove unnecessary preempt_disable in printk()"

* tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  printk: Do not disable preemption for accessing printk_func
Linus Torvalds 10 years ago
parent
commit
8f4385d590
1 changed files with 8 additions and 2 deletions
  1. 8 2
      kernel/printk/printk.c

+ 8 - 2
kernel/printk/printk.c

@@ -1857,10 +1857,16 @@ asmlinkage __visible int printk(const char *fmt, ...)
 	int r;
 	int r;
 
 
 	va_start(args, fmt);
 	va_start(args, fmt);
-	preempt_disable();
+
+	/*
+	 * If a caller overrides the per_cpu printk_func, then it needs
+	 * to disable preemption when calling printk(). Otherwise
+	 * the printk_func should be set to the default. No need to
+	 * disable preemption here.
+	 */
 	vprintk_func = this_cpu_read(printk_func);
 	vprintk_func = this_cpu_read(printk_func);
 	r = vprintk_func(fmt, args);
 	r = vprintk_func(fmt, args);
-	preempt_enable();
+
 	va_end(args);
 	va_end(args);
 
 
 	return r;
 	return r;