Two config options in the lock debugging menu that are probably the most frequently used, as far as I am concerned, is the PROVE_LOCKING and LOCK_STAT. From a UI perspective, they should be front and center. So these two options are now moved to the top of the lock debugging menu.
The DEBUG_WW_MUTEX_SLOWPATH option is also added to the PROVE_LOCKING umbrella. Signed-off-by: Waiman Long <[email protected]> --- lib/Kconfig.debug | 146 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 76 insertions(+), 70 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 6aad28c..dc9ffe2 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1034,6 +1034,79 @@ config DEBUG_PREEMPT menu "Lock Debugging (spinlocks, mutexes, etc...)" +config LOCK_DEBUGGING_SUPPORT + bool + depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + default y + +config PROVE_LOCKING + bool "Lock debugging: prove locking correctness" + depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT + select LOCKDEP + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_RT_MUTEXES if RT_MUTEXES + select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER + select DEBUG_WW_MUTEX_SLOWPATH + select DEBUG_LOCK_ALLOC + select TRACE_IRQFLAGS + default n + help + This feature enables the kernel to prove that all locking + that occurs in the kernel runtime is mathematically + correct: that under no circumstance could an arbitrary (and + not yet triggered) combination of observed locking + sequences (on an arbitrary number of CPUs, running an + arbitrary number of tasks and interrupt contexts) cause a + deadlock. + + In short, this feature enables the kernel to report locking + related deadlocks before they actually occur. + + The proof does not depend on how hard and complex a + deadlock scenario would be to trigger: how many + participant CPUs, tasks and irq-contexts would be needed + for it to trigger. The proof also does not depend on + timing: if a race and a resulting deadlock is possible + theoretically (no matter how unlikely the race scenario + is), it will be proven so and will immediately be + reported by the kernel (once the event is observed that + makes the deadlock theoretically possible). + + If a deadlock is impossible (i.e. the locking rules, as + observed by the kernel, are mathematically correct), the + kernel reports nothing. + + NOTE: this feature can also be enabled for rwlocks, mutexes + and rwsems - in which case all dependencies between these + different locking variants are observed and mapped too, and + the proof of observed correctness is also maintained for an + arbitrary combination of these separate locking variants. + + For more details, see Documentation/locking/lockdep-design.txt. + +config LOCK_STAT + bool "Lock usage statistics" + depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT + select LOCKDEP + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_RT_MUTEXES if RT_MUTEXES + select DEBUG_LOCK_ALLOC + default n + help + This feature enables tracking lock contention points + + For more details, see Documentation/locking/lockstat.txt + + This also enables lock events required by "perf lock", + subcommand of perf. + If you want to use "perf lock", you also need to turn on + CONFIG_EVENT_TRACING. + + CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. + (CONFIG_LOCKDEP defines "acquire" and "release" events.) + config DEBUG_RT_MUTEXES bool "RT Mutex debugging, deadlock detection" depends on DEBUG_KERNEL && RT_MUTEXES @@ -1060,7 +1133,7 @@ config DEBUG_MUTEXES config DEBUG_WW_MUTEX_SLOWPATH bool "Wait/wound mutex debugging: Slowpath testing" - depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select DEBUG_LOCK_ALLOC select DEBUG_SPINLOCK select DEBUG_MUTEXES @@ -1084,7 +1157,7 @@ config DEBUG_RWSEMS config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks" - depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select DEBUG_SPINLOCK select DEBUG_MUTEXES select DEBUG_RT_MUTEXES if RT_MUTEXES @@ -1097,54 +1170,9 @@ config DEBUG_LOCK_ALLOC spin_lock_init()/mutex_init()/etc., or whether there is any lock held during task exit. -config PROVE_LOCKING - bool "Lock debugging: prove locking correctness" - depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT - select LOCKDEP - select DEBUG_SPINLOCK - select DEBUG_MUTEXES - select DEBUG_RT_MUTEXES if RT_MUTEXES - select DEBUG_RWSEMS if RWSEM_SPIN_ON_OWNER - select DEBUG_LOCK_ALLOC - select TRACE_IRQFLAGS - default n - help - This feature enables the kernel to prove that all locking - that occurs in the kernel runtime is mathematically - correct: that under no circumstance could an arbitrary (and - not yet triggered) combination of observed locking - sequences (on an arbitrary number of CPUs, running an - arbitrary number of tasks and interrupt contexts) cause a - deadlock. - - In short, this feature enables the kernel to report locking - related deadlocks before they actually occur. - - The proof does not depend on how hard and complex a - deadlock scenario would be to trigger: how many - participant CPUs, tasks and irq-contexts would be needed - for it to trigger. The proof also does not depend on - timing: if a race and a resulting deadlock is possible - theoretically (no matter how unlikely the race scenario - is), it will be proven so and will immediately be - reported by the kernel (once the event is observed that - makes the deadlock theoretically possible). - - If a deadlock is impossible (i.e. the locking rules, as - observed by the kernel, are mathematically correct), the - kernel reports nothing. - - NOTE: this feature can also be enabled for rwlocks, mutexes - and rwsems - in which case all dependencies between these - different locking variants are observed and mapped too, and - the proof of observed correctness is also maintained for an - arbitrary combination of these separate locking variants. - - For more details, see Documentation/locking/lockdep-design.txt. - config LOCKDEP bool - depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select STACKTRACE select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE && !ARC && !SCORE && !X86 select KALLSYMS @@ -1153,28 +1181,6 @@ config LOCKDEP config LOCKDEP_SMALL bool -config LOCK_STAT - bool "Lock usage statistics" - depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT - select LOCKDEP - select DEBUG_SPINLOCK - select DEBUG_MUTEXES - select DEBUG_RT_MUTEXES if RT_MUTEXES - select DEBUG_LOCK_ALLOC - default n - help - This feature enables tracking lock contention points - - For more details, see Documentation/locking/lockstat.txt - - This also enables lock events required by "perf lock", - subcommand of perf. - If you want to use "perf lock", you also need to turn on - CONFIG_EVENT_TRACING. - - CONFIG_LOCK_STAT defines "contended" and "acquired" lock events. - (CONFIG_LOCKDEP defines "acquire" and "release" events.) - config DEBUG_LOCKDEP bool "Lock dependency engine debugging" depends on DEBUG_KERNEL && LOCKDEP -- 1.8.3.1
