Re: suspend-related lockdep warning

[Ingo Molnar <mingo@elte.hu>]

* Andrew Morton <akpm@linux-foundation.org> wrote:

> It would be nice to make that warning tell us that - we've hit it a 
> few times and I never knew this was the reason.

i'm a mind-reader and a time-traveler as well, so i've got the patch 
below lined up in my sched.git queue already :-)

	Ingo

-------------->
Subject: lockdep: make cli/sti annotation warnings clearer
From: Ingo Molnar <mingo@elte.hu>

make cli/sti annotation warnings easier to interpret.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 kernel/lockdep.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

Index: linux/kernel/lockdep.c
===================================================================
--- linux.orig/kernel/lockdep.c
+++ linux/kernel/lockdep.c
@@ -2654,10 +2654,15 @@ static void check_flags(unsigned long fl
 	if (!debug_locks)
 		return;
 
-	if (irqs_disabled_flags(flags))
-		DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled);
-	else
-		DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled);
+	if (irqs_disabled_flags(flags)) {
+		if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) {
+			printk("possible reason: unannotated irqs-off.\n");
+		}
+	} else {
+		if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) {
+			printk("possible reason: unannotated irqs-on.\n");
+		}
+	}
 
 	/*
 	 * We dont accurately track softirq state in e.g.