Please offer corrections / wording improvements as appropriate.
In particular, the ".+-? " table could be more illuminating - I lack the
knowledge to make the right inferences..
(or just take it, and run with it ;-)
Signed-off-by: Jim Cromie <[email protected]>
--- doc-touches/Documentation/lockdep-design.txt~ 2006-09-14 11:49:47.000000000 -0600
+++ doc-touches/Documentation/lockdep-design.txt 2006-09-15 12:46:34.000000000 -0600
@@ -36,6 +36,28 @@
- 'ever used' [ == !unused ]
+When mutex rules are violated, these 4 state bits are presented in the
+mutex error messages, inside curlies. A contrived example:
+
+ modprobe/2287 is trying to acquire lock:
+ (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
+
+ but task is already holding lock:
+ (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
+
+
+The bit position indicates hardirq, softirq, hardirq-read,
+softirq-read respectively, and the character displayed in each
+indicates:
+
+ '.' used
+ '+' used in irqs
+ '-' enabled in irqs
+ '?' used and enabled (bits 3,4)
+
+Unused mutexes cannot be part of the cause of an error.
+
+
Single-lock state rules:
------------------------