[PATCH 0/4] printk: Remove lockdep_off() and wakeups -v3

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

Last iteration of the printk() rework which removes the lockdep_off() hackery
and removes the need for printk() to issue wakeups, thereby increasing
reliability from variuos contexts.

Patch 0b5e1c5255 from -tip needs to be reverted (or better dropped), due
us discovering why doing up() under logbuf_lock was important -- thanks 
Andrew, Ingo!

This series was tested on a lockdep enabled kernel with the below hack
included, which generated a nice splat.

---
 kernel/printk.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-2.6/kernel/printk.c
===================================================================
--- linux-2.6.orig/kernel/printk.c
+++ linux-2.6/kernel/printk.c
@@ -930,6 +930,11 @@ asmlinkage int vprintk(const char *fmt, 
 	spin_lock(&logbuf_lock);
 	printk_cpu = this_cpu;
 
+	if (panic_timeout) {
+		panic_timeout = 0;
+		local_irq_enable();
+	}
+
 	if (recursion_bug) {
 		recursion_bug = 0;
 		strcpy(printk_buf, recursion_bug_msg);