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Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (33 commits)
  lockdep: fix deadlock in lockdep_trace_alloc
  lockdep: annotate reclaim context (__GFP_NOFS), fix SLOB
  lockdep: annotate reclaim context (__GFP_NOFS), fix
  lockdep: build fix for !PROVE_LOCKING
  lockstat: warn about disabled lock debugging
  lockdep: use stringify.h
  lockdep: simplify check_prev_add_irq()
  lockdep: get_user_chars() redo
  lockdep: simplify get_user_chars()
  lockdep: add comments to mark_lock_irq()
  lockdep: remove macro usage from mark_held_locks()
  lockdep: fully reduce mark_lock_irq()
  lockdep: merge the !_READ mark_lock_irq() helpers
  lockdep: merge the _READ mark_lock_irq() helpers
  lockdep: simplify mark_lock_irq() helpers #3
  lockdep: further simplify mark_lock_irq() helpers
  lockdep: simplify the mark_lock_irq() helpers
  lockdep: split up mark_lock_irq()
  lockdep: generate usage strings
  lockdep: generate the state bit definitions
  ...
This commit is contained in:
Linus Torvalds
2009-03-30 17:17:35 -07:00
parent cf2f7d7c90 2f85018152
commit c4e1aa67ed
21 changed files with 731 additions and 380 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Documentation/lockdep-design.txt
+17 -13
View File
@@ -27,33 +27,37 @@ lock-class.
State
-----
The validator tracks lock-class usage history into 5 separate state bits:
The validator tracks lock-class usage history into 4n + 1 separate state bits:
- 'ever held in hardirq context' [ == hardirq-safe ]
- 'ever held in softirq context' [ == softirq-safe ]
- 'ever held with hardirqs enabled' [ == hardirq-unsafe ]
- 'ever held with softirqs and hardirqs enabled' [ == softirq-unsafe ]
- 'ever held in STATE context'
- 'ever head as readlock in STATE context'
- 'ever head with STATE enabled'
- 'ever head as readlock with STATE enabled'
Where STATE can be either one of (kernel/lockdep_states.h)
- hardirq
- softirq
- reclaim_fs
- 'ever used' [ == !unused ]
When locking rules are violated, these 4 state bits are presented in the
locking error messages, inside curlies. A contrived example:
When locking rules are violated, these state bits are presented in the
locking error messages, inside curlies. A contrived example:
modprobe/2287 is trying to acquire lock:
(&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
(&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
(&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:
The bit position indicates STATE, STATE-read, for each of the states listed
above, and the character displayed in each indicates:
'.' acquired while irqs disabled
'+' acquired in irq context
'-' acquired with irqs enabled
'?' read acquired in irq context with irqs enabled.
'?' acquired in irq context with irqs enabled.
Unused mutexes cannot be part of the cause of an error.