config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
range 12 21
- default 17 if S390
+ default 17 if S390 || LOCKDEP
default 16 if X86_NUMAQ || IA64
default 15 if SMP
default 14
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
- depends on DEBUG_KERNEL && PREEMPT
+ depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
default y
help
If you say Y here then the kernel will use a debug variant of the
if kernel code uses it in a preemption-unsafe way. Also, the kernel
will detect preemption count underflows.
-config DEBUG_MUTEXES
- bool "Mutex debugging, deadlock detection"
- default n
- depends on DEBUG_KERNEL
- help
- This allows mutex semantics violations and mutex related deadlocks
- (lockups) to be detected and reported automatically.
-
config DEBUG_RT_MUTEXES
bool "RT Mutex debugging, deadlock detection"
depends on DEBUG_KERNEL && RT_MUTEXES
This option enables a rt-mutex tester.
config DEBUG_SPINLOCK
- bool "Spinlock debugging"
+ bool "Spinlock and rw-lock debugging: basic checks"
depends on DEBUG_KERNEL
help
Say Y here and build SMP to catch missing spinlock initialization
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config DEBUG_MUTEXES
+ bool "Mutex debugging: basic checks"
+ depends on DEBUG_KERNEL
+ help
+ This feature allows mutex semantics violations to be detected and
+ reported.
+
+config DEBUG_RWSEMS
+ bool "RW-sem debugging: basic checks"
+ depends on DEBUG_KERNEL
+ help
+ This feature allows read-write semaphore semantics violations to
+ be detected and reported.
+
+config DEBUG_LOCK_ALLOC
+ bool "Lock debugging: detect incorrect freeing of live locks"
+ depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+ select DEBUG_SPINLOCK
+ select DEBUG_MUTEXES
+ select DEBUG_RWSEMS
+ select LOCKDEP
+ help
+ This feature will check whether any held lock (spinlock, rwlock,
+ mutex or rwsem) is incorrectly freed by the kernel, via any of the
+ memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
+ vfree(), etc.), whether a live lock is incorrectly reinitialized via
+ 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_RWSEMS
+ select DEBUG_LOCK_ALLOC
+ 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/lockdep-design.txt.
+
+config LOCKDEP
+ bool
+ depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
+ select STACKTRACE
+ select FRAME_POINTER
+ select KALLSYMS
+ select KALLSYMS_ALL
+
+config DEBUG_LOCKDEP
+ bool "Lock dependency engine debugging"
+ depends on DEBUG_KERNEL && LOCKDEP
+ help
+ If you say Y here, the lock dependency engine will do
+ additional runtime checks to debug itself, at the price
+ of more runtime overhead.
+
+config TRACE_IRQFLAGS
+ depends on DEBUG_KERNEL
+ bool
+ default y
+ depends on TRACE_IRQFLAGS_SUPPORT
+ depends on PROVE_LOCKING
+
config DEBUG_SPINLOCK_SLEEP
- bool "Sleep-inside-spinlock checking"
+ bool "Spinlock debugging: sleep-inside-spinlock checking"
depends on DEBUG_KERNEL
help
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config DEBUG_LOCKING_API_SELFTESTS
+ bool "Locking API boot-time self-tests"
+ depends on DEBUG_KERNEL
+ help
+ Say Y here if you want the kernel to run a short self-test during
+ bootup. The self-test checks whether common types of locking bugs
+ are detected by debugging mechanisms or not. (if you disable
+ lock debugging then those bugs wont be detected of course.)
+ The following locking APIs are covered: spinlocks, rwlocks,
+ mutexes and rwsems.
+
+config STACKTRACE
+ bool
+ depends on DEBUG_KERNEL
+ depends on STACKTRACE_SUPPORT
+
config DEBUG_KOBJECT
bool "kobject debugging"
depends on DEBUG_KERNEL
config FRAME_POINTER
bool "Compile the kernel with frame pointers"
- depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML)
+ depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390)
default y if DEBUG_INFO && UML
help
If you say Y here the resulting kernel image will be slightly larger
projects / karo-tx-linux.git / blobdiff