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  • Ingo Molnar's avatar
    [PATCH] lockdep: better lock debugging · 9a11b49a
    Ingo Molnar authored 
    
Generic lock debugging:

 - generalized lock debugging framework. For example, a bug in one lock
   subsystem turns off debugging in all lock subsystems.

 - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
   the mutex/rtmutex debugging code: it caused way too much prototype
   hackery, and lockdep will give the same information anyway.

 - ability to do silent tests

 - check lock freeing in vfree too.

 - more finegrained debugging options, to allow distributions to
   turn off more expensive debugging features.

There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes.  (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)

Here are the current debugging options:

CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y

which do:

 config DEBUG_MUTEXES
          bool "Mutex debugging, basic checks"

 config DEBUG_LOCK_ALLOC
         bool "Detect incorrect freeing of live mutexes"
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    9a11b49a
rtmutex.h 1.1 KB
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/*
 * RT-Mutexes: blocking mutual exclusion locks with PI support
 *
 * started by Ingo Molnar and Thomas Gleixner:
 *
 *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
 *
 * This file contains macros used solely by rtmutex.c.
 * Non-debug version.
 */

#define rt_mutex_deadlock_check(l)			(0)
#define rt_mutex_deadlock_account_lock(m, t)		do { } while (0)
#define rt_mutex_deadlock_account_unlock(l)		do { } while (0)
#define debug_rt_mutex_init_waiter(w)			do { } while (0)
#define debug_rt_mutex_free_waiter(w)			do { } while (0)
#define debug_rt_mutex_lock(l)				do { } while (0)
#define debug_rt_mutex_proxy_lock(l,p)			do { } while (0)
#define debug_rt_mutex_proxy_unlock(l)			do { } while (0)
#define debug_rt_mutex_unlock(l)			do { } while (0)
#define debug_rt_mutex_init(m, n)			do { } while (0)
#define debug_rt_mutex_deadlock(d, a ,l)		do { } while (0)
#define debug_rt_mutex_print_deadlock(w)		do { } while (0)
#define debug_rt_mutex_detect_deadlock(w,d)		(d)
#define debug_rt_mutex_reset_waiter(w)			do { } while (0)