|  | 
 | config PRINTK_TIME | 
 | 	bool "Show timing information on printks" | 
 | 	depends on PRINTK | 
 | 	help | 
 | 	  Selecting this option causes timing information to be | 
 | 	  included in printk output.  This allows you to measure | 
 | 	  the interval between kernel operations, including bootup | 
 | 	  operations.  This is useful for identifying long delays | 
 | 	  in kernel startup. | 
 |  | 
 | config ENABLE_WARN_DEPRECATED | 
 | 	bool "Enable __deprecated logic" | 
 | 	default y | 
 | 	help | 
 | 	  Enable the __deprecated logic in the kernel build. | 
 | 	  Disable this to suppress the "warning: 'foo' is deprecated | 
 | 	  (declared at kernel/power/somefile.c:1234)" messages. | 
 |  | 
 | config ENABLE_MUST_CHECK | 
 | 	bool "Enable __must_check logic" | 
 | 	default y | 
 | 	help | 
 | 	  Enable the __must_check logic in the kernel build.  Disable this to | 
 | 	  suppress the "warning: ignoring return value of 'foo', declared with | 
 | 	  attribute warn_unused_result" messages. | 
 |  | 
 | config FRAME_WARN | 
 | 	int "Warn for stack frames larger than (needs gcc 4.4)" | 
 | 	range 0 8192 | 
 | 	default 1024 if !64BIT | 
 | 	default 2048 if 64BIT | 
 | 	help | 
 | 	  Tell gcc to warn at build time for stack frames larger than this. | 
 | 	  Setting this too low will cause a lot of warnings. | 
 | 	  Setting it to 0 disables the warning. | 
 | 	  Requires gcc 4.4 | 
 |  | 
 | config MAGIC_SYSRQ | 
 | 	bool "Magic SysRq key" | 
 | 	depends on !UML | 
 | 	help | 
 | 	  If you say Y here, you will have some control over the system even | 
 | 	  if the system crashes for example during kernel debugging (e.g., you | 
 | 	  will be able to flush the buffer cache to disk, reboot the system | 
 | 	  immediately or dump some status information). This is accomplished | 
 | 	  by pressing various keys while holding SysRq (Alt+PrintScreen). It | 
 | 	  also works on a serial console (on PC hardware at least), if you | 
 | 	  send a BREAK and then within 5 seconds a command keypress. The | 
 | 	  keys are documented in <file:Documentation/sysrq.txt>. Don't say Y | 
 | 	  unless you really know what this hack does. | 
 |  | 
 | config UNUSED_SYMBOLS | 
 | 	bool "Enable unused/obsolete exported symbols" | 
 | 	default y if X86 | 
 | 	help | 
 | 	  Unused but exported symbols make the kernel needlessly bigger.  For | 
 | 	  that reason most of these unused exports will soon be removed.  This | 
 | 	  option is provided temporarily to provide a transition period in case | 
 | 	  some external kernel module needs one of these symbols anyway. If you | 
 | 	  encounter such a case in your module, consider if you are actually | 
 | 	  using the right API.  (rationale: since nobody in the kernel is using | 
 | 	  this in a module, there is a pretty good chance it's actually the | 
 | 	  wrong interface to use).  If you really need the symbol, please send a | 
 | 	  mail to the linux kernel mailing list mentioning the symbol and why | 
 | 	  you really need it, and what the merge plan to the mainline kernel for | 
 | 	  your module is. | 
 |  | 
 | config DEBUG_FS | 
 | 	bool "Debug Filesystem" | 
 | 	depends on SYSFS | 
 | 	help | 
 | 	  debugfs is a virtual file system that kernel developers use to put | 
 | 	  debugging files into.  Enable this option to be able to read and | 
 | 	  write to these files. | 
 |  | 
 | 	  For detailed documentation on the debugfs API, see | 
 | 	  Documentation/DocBook/filesystems. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config HEADERS_CHECK | 
 | 	bool "Run 'make headers_check' when building vmlinux" | 
 | 	depends on !UML | 
 | 	help | 
 | 	  This option will extract the user-visible kernel headers whenever | 
 | 	  building the kernel, and will run basic sanity checks on them to | 
 | 	  ensure that exported files do not attempt to include files which | 
 | 	  were not exported, etc. | 
 |  | 
 | 	  If you're making modifications to header files which are | 
 | 	  relevant for userspace, say 'Y', and check the headers | 
 | 	  exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in | 
 | 	  your build tree), to make sure they're suitable. | 
 |  | 
 | config DEBUG_SECTION_MISMATCH | 
 | 	bool "Enable full Section mismatch analysis" | 
 | 	depends on UNDEFINED | 
 | 	# This option is on purpose disabled for now. | 
 | 	# It will be enabled when we are down to a resonable number | 
 | 	# of section mismatch warnings (< 10 for an allyesconfig build) | 
 | 	help | 
 | 	  The section mismatch analysis checks if there are illegal | 
 | 	  references from one section to another section. | 
 | 	  Linux will during link or during runtime drop some sections | 
 | 	  and any use of code/data previously in these sections will | 
 | 	  most likely result in an oops. | 
 | 	  In the code functions and variables are annotated with | 
 | 	  __init, __devinit etc. (see full list in include/linux/init.h) | 
 | 	  which results in the code/data being placed in specific sections. | 
 | 	  The section mismatch analysis is always done after a full | 
 | 	  kernel build but enabling this option will in addition | 
 | 	  do the following: | 
 | 	  - Add the option -fno-inline-functions-called-once to gcc | 
 | 	    When inlining a function annotated __init in a non-init | 
 | 	    function we would lose the section information and thus | 
 | 	    the analysis would not catch the illegal reference. | 
 | 	    This option tells gcc to inline less but will also | 
 | 	    result in a larger kernel. | 
 | 	  - Run the section mismatch analysis for each module/built-in.o | 
 | 	    When we run the section mismatch analysis on vmlinux.o we | 
 | 	    lose valueble information about where the mismatch was | 
 | 	    introduced. | 
 | 	    Running the analysis for each module/built-in.o file | 
 | 	    will tell where the mismatch happens much closer to the | 
 | 	    source. The drawback is that we will report the same | 
 | 	    mismatch at least twice. | 
 | 	  - Enable verbose reporting from modpost to help solving | 
 | 	    the section mismatches reported. | 
 |  | 
 | config DEBUG_KERNEL | 
 | 	bool "Kernel debugging" | 
 | 	help | 
 | 	  Say Y here if you are developing drivers or trying to debug and | 
 | 	  identify kernel problems. | 
 |  | 
 | config DEBUG_SHIRQ | 
 | 	bool "Debug shared IRQ handlers" | 
 | 	depends on DEBUG_KERNEL && GENERIC_HARDIRQS | 
 | 	help | 
 | 	  Enable this to generate a spurious interrupt as soon as a shared | 
 | 	  interrupt handler is registered, and just before one is deregistered. | 
 | 	  Drivers ought to be able to handle interrupts coming in at those | 
 | 	  points; some don't and need to be caught. | 
 |  | 
 | config DETECT_SOFTLOCKUP | 
 | 	bool "Detect Soft Lockups" | 
 | 	depends on DEBUG_KERNEL && !S390 | 
 | 	default y | 
 | 	help | 
 | 	  Say Y here to enable the kernel to detect "soft lockups", | 
 | 	  which are bugs that cause the kernel to loop in kernel | 
 | 	  mode for more than 60 seconds, without giving other tasks a | 
 | 	  chance to run. | 
 |  | 
 | 	  When a soft-lockup is detected, the kernel will print the | 
 | 	  current stack trace (which you should report), but the | 
 | 	  system will stay locked up. This feature has negligible | 
 | 	  overhead. | 
 |  | 
 | 	  (Note that "hard lockups" are separate type of bugs that | 
 | 	   can be detected via the NMI-watchdog, on platforms that | 
 | 	   support it.) | 
 |  | 
 | config BOOTPARAM_SOFTLOCKUP_PANIC | 
 | 	bool "Panic (Reboot) On Soft Lockups" | 
 | 	depends on DETECT_SOFTLOCKUP | 
 | 	help | 
 | 	  Say Y here to enable the kernel to panic on "soft lockups", | 
 | 	  which are bugs that cause the kernel to loop in kernel | 
 | 	  mode for more than 60 seconds, without giving other tasks a | 
 | 	  chance to run. | 
 |  | 
 | 	  The panic can be used in combination with panic_timeout, | 
 | 	  to cause the system to reboot automatically after a | 
 | 	  lockup has been detected. This feature is useful for | 
 | 	  high-availability systems that have uptime guarantees and | 
 | 	  where a lockup must be resolved ASAP. | 
 |  | 
 | 	  Say N if unsure. | 
 |  | 
 | config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE | 
 | 	int | 
 | 	depends on DETECT_SOFTLOCKUP | 
 | 	range 0 1 | 
 | 	default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC | 
 | 	default 1 if BOOTPARAM_SOFTLOCKUP_PANIC | 
 |  | 
 | config SCHED_DEBUG | 
 | 	bool "Collect scheduler debugging info" | 
 | 	depends on DEBUG_KERNEL && PROC_FS | 
 | 	default y | 
 | 	help | 
 | 	  If you say Y here, the /proc/sched_debug file will be provided | 
 | 	  that can help debug the scheduler. The runtime overhead of this | 
 | 	  option is minimal. | 
 |  | 
 | config SCHEDSTATS | 
 | 	bool "Collect scheduler statistics" | 
 | 	depends on DEBUG_KERNEL && PROC_FS | 
 | 	help | 
 | 	  If you say Y here, additional code will be inserted into the | 
 | 	  scheduler and related routines to collect statistics about | 
 | 	  scheduler behavior and provide them in /proc/schedstat.  These | 
 | 	  stats may be useful for both tuning and debugging the scheduler | 
 | 	  If you aren't debugging the scheduler or trying to tune a specific | 
 | 	  application, you can say N to avoid the very slight overhead | 
 | 	  this adds. | 
 |  | 
 | config TIMER_STATS | 
 | 	bool "Collect kernel timers statistics" | 
 | 	depends on DEBUG_KERNEL && PROC_FS | 
 | 	help | 
 | 	  If you say Y here, additional code will be inserted into the | 
 | 	  timer routines to collect statistics about kernel timers being | 
 | 	  reprogrammed. The statistics can be read from /proc/timer_stats. | 
 | 	  The statistics collection is started by writing 1 to /proc/timer_stats, | 
 | 	  writing 0 stops it. This feature is useful to collect information | 
 | 	  about timer usage patterns in kernel and userspace. This feature | 
 | 	  is lightweight if enabled in the kernel config but not activated | 
 | 	  (it defaults to deactivated on bootup and will only be activated | 
 | 	  if some application like powertop activates it explicitly). | 
 |  | 
 | config DEBUG_OBJECTS | 
 | 	bool "Debug object operations" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  If you say Y here, additional code will be inserted into the | 
 | 	  kernel to track the life time of various objects and validate | 
 | 	  the operations on those objects. | 
 |  | 
 | config DEBUG_OBJECTS_SELFTEST | 
 | 	bool "Debug objects selftest" | 
 | 	depends on DEBUG_OBJECTS | 
 | 	help | 
 | 	  This enables the selftest of the object debug code. | 
 |  | 
 | config DEBUG_OBJECTS_FREE | 
 | 	bool "Debug objects in freed memory" | 
 | 	depends on DEBUG_OBJECTS | 
 | 	help | 
 | 	  This enables checks whether a k/v free operation frees an area | 
 | 	  which contains an object which has not been deactivated | 
 | 	  properly. This can make kmalloc/kfree-intensive workloads | 
 | 	  much slower. | 
 |  | 
 | config DEBUG_OBJECTS_TIMERS | 
 | 	bool "Debug timer objects" | 
 | 	depends on DEBUG_OBJECTS | 
 | 	help | 
 | 	  If you say Y here, additional code will be inserted into the | 
 | 	  timer routines to track the life time of timer objects and | 
 | 	  validate the timer operations. | 
 |  | 
 | config DEBUG_SLAB | 
 | 	bool "Debug slab memory allocations" | 
 | 	depends on DEBUG_KERNEL && SLAB | 
 | 	help | 
 | 	  Say Y here to have the kernel do limited verification on memory | 
 | 	  allocation as well as poisoning memory on free to catch use of freed | 
 | 	  memory. This can make kmalloc/kfree-intensive workloads much slower. | 
 |  | 
 | config DEBUG_SLAB_LEAK | 
 | 	bool "Memory leak debugging" | 
 | 	depends on DEBUG_SLAB | 
 |  | 
 | config SLUB_DEBUG_ON | 
 | 	bool "SLUB debugging on by default" | 
 | 	depends on SLUB && SLUB_DEBUG | 
 | 	default n | 
 | 	help | 
 | 	  Boot with debugging on by default. SLUB boots by default with | 
 | 	  the runtime debug capabilities switched off. Enabling this is | 
 | 	  equivalent to specifying the "slub_debug" parameter on boot. | 
 | 	  There is no support for more fine grained debug control like | 
 | 	  possible with slub_debug=xxx. SLUB debugging may be switched | 
 | 	  off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying | 
 | 	  "slub_debug=-". | 
 |  | 
 | config SLUB_STATS | 
 | 	default n | 
 | 	bool "Enable SLUB performance statistics" | 
 | 	depends on SLUB && SLUB_DEBUG && SYSFS | 
 | 	help | 
 | 	  SLUB statistics are useful to debug SLUBs allocation behavior in | 
 | 	  order find ways to optimize the allocator. This should never be | 
 | 	  enabled for production use since keeping statistics slows down | 
 | 	  the allocator by a few percentage points. The slabinfo command | 
 | 	  supports the determination of the most active slabs to figure | 
 | 	  out which slabs are relevant to a particular load. | 
 | 	  Try running: slabinfo -DA | 
 |  | 
 | config DEBUG_PREEMPT | 
 | 	bool "Debug preemptible kernel" | 
 | 	depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64) | 
 | 	default y | 
 | 	help | 
 | 	  If you say Y here then the kernel will use a debug variant of the | 
 | 	  commonly used smp_processor_id() function and will print warnings | 
 | 	  if kernel code uses it in a preemption-unsafe way. Also, the kernel | 
 | 	  will detect preemption count underflows. | 
 |  | 
 | config DEBUG_RT_MUTEXES | 
 | 	bool "RT Mutex debugging, deadlock detection" | 
 | 	depends on DEBUG_KERNEL && RT_MUTEXES | 
 | 	help | 
 | 	 This allows rt mutex semantics violations and rt mutex related | 
 | 	 deadlocks (lockups) to be detected and reported automatically. | 
 |  | 
 | config DEBUG_PI_LIST | 
 | 	bool | 
 | 	default y | 
 | 	depends on DEBUG_RT_MUTEXES | 
 |  | 
 | config RT_MUTEX_TESTER | 
 | 	bool "Built-in scriptable tester for rt-mutexes" | 
 | 	depends on DEBUG_KERNEL && RT_MUTEXES | 
 | 	help | 
 | 	  This option enables a rt-mutex tester. | 
 |  | 
 | config DEBUG_SPINLOCK | 
 | 	bool "Spinlock and rw-lock debugging: basic checks" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  Say Y here and build SMP to catch missing spinlock initialization | 
 | 	  and certain other kinds of spinlock errors commonly made.  This is | 
 | 	  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_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 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_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 if !X86 && !MIPS && !PPC | 
 | 	select KALLSYMS | 
 | 	select KALLSYMS_ALL | 
 |  | 
 | 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_LOCK_ALLOC | 
 | 	default n | 
 | 	help | 
 | 	 This feature enables tracking lock contention points | 
 |  | 
 | 	 For more details, see Documentation/lockstat.txt | 
 |  | 
 | 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 "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 STACKTRACE_SUPPORT | 
 |  | 
 | config DEBUG_KOBJECT | 
 | 	bool "kobject debugging" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  If you say Y here, some extra kobject debugging messages will be sent | 
 | 	  to the syslog.  | 
 |  | 
 | config DEBUG_HIGHMEM | 
 | 	bool "Highmem debugging" | 
 | 	depends on DEBUG_KERNEL && HIGHMEM | 
 | 	help | 
 | 	  This options enables addition error checking for high memory systems. | 
 | 	  Disable for production systems. | 
 |  | 
 | config DEBUG_BUGVERBOSE | 
 | 	bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED | 
 | 	depends on BUG | 
 | 	depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ | 
 | 		   FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 | 
 | 	default !EMBEDDED | 
 | 	help | 
 | 	  Say Y here to make BUG() panics output the file name and line number | 
 | 	  of the BUG call as well as the EIP and oops trace.  This aids | 
 | 	  debugging but costs about 70-100K of memory. | 
 |  | 
 | config DEBUG_INFO | 
 | 	bool "Compile the kernel with debug info" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 |           If you say Y here the resulting kernel image will include | 
 | 	  debugging info resulting in a larger kernel image. | 
 | 	  This adds debug symbols to the kernel and modules (gcc -g), and | 
 | 	  is needed if you intend to use kernel crashdump or binary object | 
 | 	  tools like crash, kgdb, LKCD, gdb, etc on the kernel. | 
 | 	  Say Y here only if you plan to debug the kernel. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config DEBUG_VM | 
 | 	bool "Debug VM" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  Enable this to turn on extended checks in the virtual-memory system | 
 |           that may impact performance. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config DEBUG_VIRTUAL | 
 | 	bool "Debug VM translations" | 
 | 	depends on DEBUG_KERNEL && X86 | 
 | 	help | 
 | 	  Enable some costly sanity checks in virtual to page code. This can | 
 | 	  catch mistakes with virt_to_page() and friends. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config DEBUG_WRITECOUNT | 
 | 	bool "Debug filesystem writers count" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  Enable this to catch wrong use of the writers count in struct | 
 | 	  vfsmount.  This will increase the size of each file struct by | 
 | 	  32 bits. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config DEBUG_MEMORY_INIT | 
 | 	bool "Debug memory initialisation" if EMBEDDED | 
 | 	default !EMBEDDED | 
 | 	help | 
 | 	  Enable this for additional checks during memory initialisation. | 
 | 	  The sanity checks verify aspects of the VM such as the memory model | 
 | 	  and other information provided by the architecture. Verbose | 
 | 	  information will be printed at KERN_DEBUG loglevel depending | 
 | 	  on the mminit_loglevel= command-line option. | 
 |  | 
 | 	  If unsure, say Y | 
 |  | 
 | config DEBUG_LIST | 
 | 	bool "Debug linked list manipulation" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  Enable this to turn on extended checks in the linked-list | 
 | 	  walking routines. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config DEBUG_SG | 
 | 	bool "Debug SG table operations" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  Enable this to turn on checks on scatter-gather tables. This can | 
 | 	  help find problems with drivers that do not properly initialize | 
 | 	  their sg tables. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | config FRAME_POINTER | 
 | 	bool "Compile the kernel with frame pointers" | 
 | 	depends on DEBUG_KERNEL && \ | 
 | 		(X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \ | 
 | 		 AVR32 || SUPERH || BLACKFIN || MN10300) | 
 | 	default y if DEBUG_INFO && UML | 
 | 	help | 
 | 	  If you say Y here the resulting kernel image will be slightly larger | 
 | 	  and slower, but it might give very useful debugging information on | 
 | 	  some architectures or if you use external debuggers. | 
 | 	  If you don't debug the kernel, you can say N. | 
 |  | 
 | config BOOT_PRINTK_DELAY | 
 | 	bool "Delay each boot printk message by N milliseconds" | 
 | 	depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY | 
 | 	help | 
 | 	  This build option allows you to read kernel boot messages | 
 | 	  by inserting a short delay after each one.  The delay is | 
 | 	  specified in milliseconds on the kernel command line, | 
 | 	  using "boot_delay=N". | 
 |  | 
 | 	  It is likely that you would also need to use "lpj=M" to preset | 
 | 	  the "loops per jiffie" value. | 
 | 	  See a previous boot log for the "lpj" value to use for your | 
 | 	  system, and then set "lpj=M" before setting "boot_delay=N". | 
 | 	  NOTE:  Using this option may adversely affect SMP systems. | 
 | 	  I.e., processors other than the first one may not boot up. | 
 | 	  BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect | 
 | 	  what it believes to be lockup conditions. | 
 |  | 
 | config RCU_TORTURE_TEST | 
 | 	tristate "torture tests for RCU" | 
 | 	depends on DEBUG_KERNEL | 
 | 	default n | 
 | 	help | 
 | 	  This option provides a kernel module that runs torture tests | 
 | 	  on the RCU infrastructure.  The kernel module may be built | 
 | 	  after the fact on the running kernel to be tested, if desired. | 
 |  | 
 | 	  Say Y here if you want RCU torture tests to be built into | 
 | 	  the kernel. | 
 | 	  Say M if you want the RCU torture tests to build as a module. | 
 | 	  Say N if you are unsure. | 
 |  | 
 | config RCU_TORTURE_TEST_RUNNABLE | 
 | 	bool "torture tests for RCU runnable by default" | 
 | 	depends on RCU_TORTURE_TEST = y | 
 | 	default n | 
 | 	help | 
 | 	  This option provides a way to build the RCU torture tests | 
 | 	  directly into the kernel without them starting up at boot | 
 | 	  time.  You can use /proc/sys/kernel/rcutorture_runnable | 
 | 	  to manually override this setting.  This /proc file is | 
 | 	  available only when the RCU torture tests have been built | 
 | 	  into the kernel. | 
 |  | 
 | 	  Say Y here if you want the RCU torture tests to start during | 
 | 	  boot (you probably don't). | 
 | 	  Say N here if you want the RCU torture tests to start only | 
 | 	  after being manually enabled via /proc. | 
 |  | 
 | config RCU_CPU_STALL_DETECTOR | 
 | 	bool "Check for stalled CPUs delaying RCU grace periods" | 
 | 	depends on CLASSIC_RCU | 
 | 	default n | 
 | 	help | 
 | 	  This option causes RCU to printk information on which | 
 | 	  CPUs are delaying the current grace period, but only when | 
 | 	  the grace period extends for excessive time periods. | 
 |  | 
 | 	  Say Y if you want RCU to perform such checks. | 
 |  | 
 | 	  Say N if you are unsure. | 
 |  | 
 | config KPROBES_SANITY_TEST | 
 | 	bool "Kprobes sanity tests" | 
 | 	depends on DEBUG_KERNEL | 
 | 	depends on KPROBES | 
 | 	default n | 
 | 	help | 
 | 	  This option provides for testing basic kprobes functionality on | 
 | 	  boot. A sample kprobe, jprobe and kretprobe are inserted and | 
 | 	  verified for functionality. | 
 |  | 
 | 	  Say N if you are unsure. | 
 |  | 
 | config BACKTRACE_SELF_TEST | 
 | 	tristate "Self test for the backtrace code" | 
 | 	depends on DEBUG_KERNEL | 
 | 	default n | 
 | 	help | 
 | 	  This option provides a kernel module that can be used to test | 
 | 	  the kernel stack backtrace code. This option is not useful | 
 | 	  for distributions or general kernels, but only for kernel | 
 | 	  developers working on architecture code. | 
 |  | 
 | 	  Note that if you want to also test saved backtraces, you will | 
 | 	  have to enable STACKTRACE as well. | 
 |  | 
 | 	  Say N if you are unsure. | 
 |  | 
 | config DEBUG_BLOCK_EXT_DEVT | 
 |         bool "Force extended block device numbers and spread them" | 
 | 	depends on DEBUG_KERNEL | 
 | 	depends on BLOCK | 
 | 	default n | 
 | 	help | 
 | 	  BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON | 
 | 	  SOME DISTRIBUTIONS.  DO NOT ENABLE THIS UNLESS YOU KNOW WHAT | 
 | 	  YOU ARE DOING.  Distros, please enable this and fix whatever | 
 | 	  is broken. | 
 |  | 
 | 	  Conventionally, block device numbers are allocated from | 
 | 	  predetermined contiguous area.  However, extended block area | 
 | 	  may introduce non-contiguous block device numbers.  This | 
 | 	  option forces most block device numbers to be allocated from | 
 | 	  the extended space and spreads them to discover kernel or | 
 | 	  userland code paths which assume predetermined contiguous | 
 | 	  device number allocation. | 
 |  | 
 | 	  Note that turning on this debug option shuffles all the | 
 | 	  device numbers for all IDE and SCSI devices including libata | 
 | 	  ones, so root partition specified using device number | 
 | 	  directly (via rdev or root=MAJ:MIN) won't work anymore. | 
 | 	  Textual device names (root=/dev/sdXn) will continue to work. | 
 |  | 
 | 	  Say N if you are unsure. | 
 |  | 
 | config LKDTM | 
 | 	tristate "Linux Kernel Dump Test Tool Module" | 
 | 	depends on DEBUG_KERNEL | 
 | 	depends on KPROBES | 
 | 	depends on BLOCK | 
 | 	default n | 
 | 	help | 
 | 	This module enables testing of the different dumping mechanisms by | 
 | 	inducing system failures at predefined crash points. | 
 | 	If you don't need it: say N | 
 | 	Choose M here to compile this code as a module. The module will be | 
 | 	called lkdtm. | 
 |  | 
 | 	Documentation on how to use the module can be found in | 
 | 	drivers/misc/lkdtm.c | 
 |  | 
 | config FAULT_INJECTION | 
 | 	bool "Fault-injection framework" | 
 | 	depends on DEBUG_KERNEL | 
 | 	help | 
 | 	  Provide fault-injection framework. | 
 | 	  For more details, see Documentation/fault-injection/. | 
 |  | 
 | config FAILSLAB | 
 | 	bool "Fault-injection capability for kmalloc" | 
 | 	depends on FAULT_INJECTION | 
 | 	help | 
 | 	  Provide fault-injection capability for kmalloc. | 
 |  | 
 | config FAIL_PAGE_ALLOC | 
 | 	bool "Fault-injection capabilitiy for alloc_pages()" | 
 | 	depends on FAULT_INJECTION | 
 | 	help | 
 | 	  Provide fault-injection capability for alloc_pages(). | 
 |  | 
 | config FAIL_MAKE_REQUEST | 
 | 	bool "Fault-injection capability for disk IO" | 
 | 	depends on FAULT_INJECTION && BLOCK | 
 | 	help | 
 | 	  Provide fault-injection capability for disk IO. | 
 |  | 
 | config FAIL_IO_TIMEOUT | 
 | 	bool "Faul-injection capability for faking disk interrupts" | 
 | 	depends on FAULT_INJECTION && BLOCK | 
 | 	help | 
 | 	  Provide fault-injection capability on end IO handling. This | 
 | 	  will make the block layer "forget" an interrupt as configured, | 
 | 	  thus exercising the error handling. | 
 |  | 
 | 	  Only works with drivers that use the generic timeout handling, | 
 | 	  for others it wont do anything. | 
 |  | 
 | config FAULT_INJECTION_DEBUG_FS | 
 | 	bool "Debugfs entries for fault-injection capabilities" | 
 | 	depends on FAULT_INJECTION && SYSFS && DEBUG_FS | 
 | 	help | 
 | 	  Enable configuration of fault-injection capabilities via debugfs. | 
 |  | 
 | config FAULT_INJECTION_STACKTRACE_FILTER | 
 | 	bool "stacktrace filter for fault-injection capabilities" | 
 | 	depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT | 
 | 	depends on !X86_64 | 
 | 	select STACKTRACE | 
 | 	select FRAME_POINTER if !PPC | 
 | 	help | 
 | 	  Provide stacktrace filter for fault-injection capabilities | 
 |  | 
 | config LATENCYTOP | 
 | 	bool "Latency measuring infrastructure" | 
 | 	select FRAME_POINTER if !MIPS && !PPC | 
 | 	select KALLSYMS | 
 | 	select KALLSYMS_ALL | 
 | 	select STACKTRACE | 
 | 	select SCHEDSTATS | 
 | 	select SCHED_DEBUG | 
 | 	depends on HAVE_LATENCYTOP_SUPPORT | 
 | 	help | 
 | 	  Enable this option if you want to use the LatencyTOP tool | 
 | 	  to find out which userspace is blocking on what kernel operations. | 
 |  | 
 | config SYSCTL_SYSCALL_CHECK | 
 | 	bool "Sysctl checks" | 
 | 	depends on SYSCTL_SYSCALL | 
 | 	---help--- | 
 | 	  sys_sysctl uses binary paths that have been found challenging | 
 | 	  to properly maintain and use. This enables checks that help | 
 | 	  you to keep things correct. | 
 |  | 
 | source kernel/trace/Kconfig | 
 |  | 
 | config PROVIDE_OHCI1394_DMA_INIT | 
 | 	bool "Remote debugging over FireWire early on boot" | 
 | 	depends on PCI && X86 | 
 | 	help | 
 | 	  If you want to debug problems which hang or crash the kernel early | 
 | 	  on boot and the crashing machine has a FireWire port, you can use | 
 | 	  this feature to remotely access the memory of the crashed machine | 
 | 	  over FireWire. This employs remote DMA as part of the OHCI1394 | 
 | 	  specification which is now the standard for FireWire controllers. | 
 |  | 
 | 	  With remote DMA, you can monitor the printk buffer remotely using | 
 | 	  firescope and access all memory below 4GB using fireproxy from gdb. | 
 | 	  Even controlling a kernel debugger is possible using remote DMA. | 
 |  | 
 | 	  Usage: | 
 |  | 
 | 	  If ohci1394_dma=early is used as boot parameter, it will initialize | 
 | 	  all OHCI1394 controllers which are found in the PCI config space. | 
 |  | 
 | 	  As all changes to the FireWire bus such as enabling and disabling | 
 | 	  devices cause a bus reset and thereby disable remote DMA for all | 
 | 	  devices, be sure to have the cable plugged and FireWire enabled on | 
 | 	  the debugging host before booting the debug target for debugging. | 
 |  | 
 | 	  This code (~1k) is freed after boot. By then, the firewire stack | 
 | 	  in charge of the OHCI-1394 controllers should be used instead. | 
 |  | 
 | 	  See Documentation/debugging-via-ohci1394.txt for more information. | 
 |  | 
 | config FIREWIRE_OHCI_REMOTE_DMA | 
 | 	bool "Remote debugging over FireWire with firewire-ohci" | 
 | 	depends on FIREWIRE_OHCI | 
 | 	help | 
 | 	  This option lets you use the FireWire bus for remote debugging | 
 | 	  with help of the firewire-ohci driver. It enables unfiltered | 
 | 	  remote DMA in firewire-ohci. | 
 | 	  See Documentation/debugging-via-ohci1394.txt for more information. | 
 |  | 
 | 	  If unsure, say N. | 
 |  | 
 | menuconfig BUILD_DOCSRC | 
 | 	bool "Build targets in Documentation/ tree" | 
 | 	depends on HEADERS_CHECK | 
 | 	help | 
 | 	  This option attempts to build objects from the source files in the | 
 | 	  kernel Documentation/ tree. | 
 |  | 
 | 	  Say N if you are unsure. | 
 |  | 
 | config DYNAMIC_PRINTK_DEBUG | 
 | 	bool "Enable dynamic printk() call support" | 
 | 	default n | 
 | 	depends on PRINTK | 
 | 	select PRINTK_DEBUG | 
 | 	help | 
 |  | 
 | 	  Compiles debug level messages into the kernel, which would not | 
 | 	  otherwise be available at runtime. These messages can then be | 
 | 	  enabled/disabled on a per module basis. This mechanism implicitly | 
 | 	  enables all pr_debug() and dev_dbg() calls. The impact of this | 
 | 	  compile option is a larger kernel text size of about 2%. | 
 |  | 
 | 	  Usage: | 
 |  | 
 | 	  Dynamic debugging is controlled by the debugfs file, | 
 | 	  dynamic_printk/modules. This file contains a list of the modules that | 
 | 	  can be enabled. The format of the file is the module name, followed | 
 | 	  by a set of flags that can be enabled. The first flag is always the | 
 | 	  'enabled' flag. For example: | 
 |  | 
 | 		<module_name> <enabled=0/1> | 
 | 				. | 
 | 				. | 
 | 				. | 
 |  | 
 | 	  <module_name> : Name of the module in which the debug call resides | 
 | 	  <enabled=0/1> : whether the messages are enabled or not | 
 |  | 
 | 	  From a live system: | 
 |  | 
 | 		snd_hda_intel enabled=0 | 
 | 		fixup enabled=0 | 
 | 		driver enabled=0 | 
 |  | 
 | 	  Enable a module: | 
 |  | 
 | 	  	$echo "set enabled=1 <module_name>" > dynamic_printk/modules | 
 |  | 
 | 	  Disable a module: | 
 |  | 
 | 	  	$echo "set enabled=0 <module_name>" > dynamic_printk/modules | 
 |  | 
 | 	  Enable all modules: | 
 |  | 
 | 		$echo "set enabled=1 all" > dynamic_printk/modules | 
 |  | 
 | 	  Disable all modules: | 
 |  | 
 | 		$echo "set enabled=0 all" > dynamic_printk/modules | 
 |  | 
 | 	  Finally, passing "dynamic_printk" at the command line enables | 
 | 	  debugging for all modules. This mode can be turned off via the above | 
 | 	  disable command. | 
 |  | 
 | source "samples/Kconfig" | 
 |  | 
 | source "lib/Kconfig.kgdb" |