535 lines
18 KiB
Plaintext
535 lines
18 KiB
Plaintext
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config PRINTK_TIME
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bool "Show timing information on printks"
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depends on PRINTK
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help
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Selecting this option causes timing information to be
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included in printk output. This allows you to measure
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the interval between kernel operations, including bootup
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operations. This is useful for identifying long delays
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in kernel startup.
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config ENABLE_WARN_DEPRECATED
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bool "Enable __deprecated logic"
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default y
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help
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Enable the __deprecated logic in the kernel build.
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Disable this to suppress the "warning: 'foo' is deprecated
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(declared at kernel/power/somefile.c:1234)" messages.
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config ENABLE_MUST_CHECK
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bool "Enable __must_check logic"
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default y
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help
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Enable the __must_check logic in the kernel build. Disable this to
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suppress the "warning: ignoring return value of 'foo', declared with
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attribute warn_unused_result" messages.
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config MAGIC_SYSRQ
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bool "Magic SysRq key"
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depends on !UML
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help
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If you say Y here, you will have some control over the system even
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if the system crashes for example during kernel debugging (e.g., you
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will be able to flush the buffer cache to disk, reboot the system
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immediately or dump some status information). This is accomplished
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by pressing various keys while holding SysRq (Alt+PrintScreen). It
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also works on a serial console (on PC hardware at least), if you
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send a BREAK and then within 5 seconds a command keypress. The
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keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
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unless you really know what this hack does.
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config UNUSED_SYMBOLS
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bool "Enable unused/obsolete exported symbols"
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default y if X86
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help
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Unused but exported symbols make the kernel needlessly bigger. For
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that reason most of these unused exports will soon be removed. This
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option is provided temporarily to provide a transition period in case
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some external kernel module needs one of these symbols anyway. If you
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encounter such a case in your module, consider if you are actually
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using the right API. (rationale: since nobody in the kernel is using
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this in a module, there is a pretty good chance it's actually the
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wrong interface to use). If you really need the symbol, please send a
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mail to the linux kernel mailing list mentioning the symbol and why
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you really need it, and what the merge plan to the mainline kernel for
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your module is.
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config DEBUG_FS
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bool "Debug Filesystem"
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depends on SYSFS
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help
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debugfs is a virtual file system that kernel developers use to put
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debugging files into. Enable this option to be able to read and
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write to these files.
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If unsure, say N.
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config HEADERS_CHECK
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bool "Run 'make headers_check' when building vmlinux"
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depends on !UML
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help
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This option will extract the user-visible kernel headers whenever
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building the kernel, and will run basic sanity checks on them to
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ensure that exported files do not attempt to include files which
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were not exported, etc.
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If you're making modifications to header files which are
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relevant for userspace, say 'Y', and check the headers
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exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
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your build tree), to make sure they're suitable.
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config DEBUG_KERNEL
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bool "Kernel debugging"
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help
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Say Y here if you are developing drivers or trying to debug and
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identify kernel problems.
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config DEBUG_SHIRQ
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bool "Debug shared IRQ handlers"
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depends on DEBUG_KERNEL && GENERIC_HARDIRQS
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help
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Enable this to generate a spurious interrupt as soon as a shared
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interrupt handler is registered, and just before one is deregistered.
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Drivers ought to be able to handle interrupts coming in at those
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points; some don't and need to be caught.
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config DETECT_SOFTLOCKUP
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bool "Detect Soft Lockups"
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depends on DEBUG_KERNEL && !S390
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default y
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help
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Say Y here to enable the kernel to detect "soft lockups",
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which are bugs that cause the kernel to loop in kernel
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mode for more than 10 seconds, without giving other tasks a
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chance to run.
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When a soft-lockup is detected, the kernel will print the
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current stack trace (which you should report), but the
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system will stay locked up. This feature has negligible
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overhead.
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(Note that "hard lockups" are separate type of bugs that
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can be detected via the NMI-watchdog, on platforms that
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support it.)
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config SCHED_DEBUG
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bool "Collect scheduler debugging info"
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depends on DEBUG_KERNEL && PROC_FS
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default y
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help
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If you say Y here, the /proc/sched_debug file will be provided
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that can help debug the scheduler. The runtime overhead of this
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option is minimal.
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config SCHEDSTATS
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bool "Collect scheduler statistics"
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depends on DEBUG_KERNEL && PROC_FS
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help
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If you say Y here, additional code will be inserted into the
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scheduler and related routines to collect statistics about
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scheduler behavior and provide them in /proc/schedstat. These
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stats may be useful for both tuning and debugging the scheduler
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If you aren't debugging the scheduler or trying to tune a specific
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application, you can say N to avoid the very slight overhead
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this adds.
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config TIMER_STATS
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bool "Collect kernel timers statistics"
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depends on DEBUG_KERNEL && PROC_FS
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help
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If you say Y here, additional code will be inserted into the
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timer routines to collect statistics about kernel timers being
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reprogrammed. The statistics can be read from /proc/timer_stats.
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The statistics collection is started by writing 1 to /proc/timer_stats,
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writing 0 stops it. This feature is useful to collect information
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about timer usage patterns in kernel and userspace. This feature
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is lightweight if enabled in the kernel config but not activated
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(it defaults to deactivated on bootup and will only be activated
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if some application like powertop activates it explicitly).
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config DEBUG_SLAB
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bool "Debug slab memory allocations"
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depends on DEBUG_KERNEL && SLAB
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help
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Say Y here to have the kernel do limited verification on memory
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allocation as well as poisoning memory on free to catch use of freed
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memory. This can make kmalloc/kfree-intensive workloads much slower.
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config DEBUG_SLAB_LEAK
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bool "Memory leak debugging"
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depends on DEBUG_SLAB
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config SLUB_DEBUG_ON
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bool "SLUB debugging on by default"
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depends on SLUB && SLUB_DEBUG
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default n
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help
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Boot with debugging on by default. SLUB boots by default with
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the runtime debug capabilities switched off. Enabling this is
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equivalent to specifying the "slub_debug" parameter on boot.
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There is no support for more fine grained debug control like
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possible with slub_debug=xxx. SLUB debugging may be switched
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off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
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"slub_debug=-".
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config DEBUG_PREEMPT
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bool "Debug preemptible kernel"
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depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
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default y
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help
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If you say Y here then the kernel will use a debug variant of the
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commonly used smp_processor_id() function and will print warnings
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if kernel code uses it in a preemption-unsafe way. Also, the kernel
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will detect preemption count underflows.
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config DEBUG_RT_MUTEXES
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bool "RT Mutex debugging, deadlock detection"
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depends on DEBUG_KERNEL && RT_MUTEXES
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help
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This allows rt mutex semantics violations and rt mutex related
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deadlocks (lockups) to be detected and reported automatically.
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config DEBUG_PI_LIST
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bool
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default y
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depends on DEBUG_RT_MUTEXES
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config RT_MUTEX_TESTER
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bool "Built-in scriptable tester for rt-mutexes"
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depends on DEBUG_KERNEL && RT_MUTEXES
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help
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This option enables a rt-mutex tester.
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config DEBUG_SPINLOCK
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bool "Spinlock and rw-lock debugging: basic checks"
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depends on DEBUG_KERNEL
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help
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Say Y here and build SMP to catch missing spinlock initialization
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and certain other kinds of spinlock errors commonly made. This is
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best used in conjunction with the NMI watchdog so that spinlock
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deadlocks are also debuggable.
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config DEBUG_MUTEXES
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bool "Mutex debugging: basic checks"
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depends on DEBUG_KERNEL
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help
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This feature allows mutex semantics violations to be detected and
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reported.
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config DEBUG_SEMAPHORE
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bool "Semaphore debugging"
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depends on DEBUG_KERNEL
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depends on ALPHA || FRV
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default n
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help
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If you say Y here then semaphore processing will issue lots of
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verbose debugging messages. If you suspect a semaphore problem or a
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kernel hacker asks for this option then say Y. Otherwise say N.
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config DEBUG_LOCK_ALLOC
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bool "Lock debugging: detect incorrect freeing of live locks"
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depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
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select DEBUG_SPINLOCK
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select DEBUG_MUTEXES
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select LOCKDEP
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help
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This feature will check whether any held lock (spinlock, rwlock,
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mutex or rwsem) is incorrectly freed by the kernel, via any of the
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memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
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vfree(), etc.), whether a live lock is incorrectly reinitialized via
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spin_lock_init()/mutex_init()/etc., or whether there is any lock
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held during task exit.
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config PROVE_LOCKING
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bool "Lock debugging: prove locking correctness"
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depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
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select LOCKDEP
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select DEBUG_SPINLOCK
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select DEBUG_MUTEXES
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select DEBUG_LOCK_ALLOC
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default n
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help
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This feature enables the kernel to prove that all locking
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that occurs in the kernel runtime is mathematically
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correct: that under no circumstance could an arbitrary (and
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not yet triggered) combination of observed locking
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sequences (on an arbitrary number of CPUs, running an
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arbitrary number of tasks and interrupt contexts) cause a
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deadlock.
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In short, this feature enables the kernel to report locking
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related deadlocks before they actually occur.
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The proof does not depend on how hard and complex a
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deadlock scenario would be to trigger: how many
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participant CPUs, tasks and irq-contexts would be needed
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for it to trigger. The proof also does not depend on
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timing: if a race and a resulting deadlock is possible
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theoretically (no matter how unlikely the race scenario
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is), it will be proven so and will immediately be
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reported by the kernel (once the event is observed that
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makes the deadlock theoretically possible).
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If a deadlock is impossible (i.e. the locking rules, as
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observed by the kernel, are mathematically correct), the
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kernel reports nothing.
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NOTE: this feature can also be enabled for rwlocks, mutexes
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and rwsems - in which case all dependencies between these
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different locking variants are observed and mapped too, and
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the proof of observed correctness is also maintained for an
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arbitrary combination of these separate locking variants.
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For more details, see Documentation/lockdep-design.txt.
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config LOCKDEP
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bool
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depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
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select STACKTRACE
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select FRAME_POINTER if !X86 && !MIPS
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select KALLSYMS
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select KALLSYMS_ALL
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config LOCK_STAT
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bool "Lock usage statistics"
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depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
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select LOCKDEP
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select DEBUG_SPINLOCK
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select DEBUG_MUTEXES
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select DEBUG_LOCK_ALLOC
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default n
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help
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This feature enables tracking lock contention points
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For more details, see Documentation/lockstat.txt
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config DEBUG_LOCKDEP
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bool "Lock dependency engine debugging"
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depends on DEBUG_KERNEL && LOCKDEP
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help
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If you say Y here, the lock dependency engine will do
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additional runtime checks to debug itself, at the price
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of more runtime overhead.
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config TRACE_IRQFLAGS
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depends on DEBUG_KERNEL
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bool
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default y
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depends on TRACE_IRQFLAGS_SUPPORT
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depends on PROVE_LOCKING
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config DEBUG_SPINLOCK_SLEEP
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bool "Spinlock debugging: sleep-inside-spinlock checking"
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depends on DEBUG_KERNEL
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help
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If you say Y here, various routines which may sleep will become very
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noisy if they are called with a spinlock held.
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config DEBUG_LOCKING_API_SELFTESTS
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bool "Locking API boot-time self-tests"
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depends on DEBUG_KERNEL
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help
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Say Y here if you want the kernel to run a short self-test during
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bootup. The self-test checks whether common types of locking bugs
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are detected by debugging mechanisms or not. (if you disable
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lock debugging then those bugs wont be detected of course.)
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The following locking APIs are covered: spinlocks, rwlocks,
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mutexes and rwsems.
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config STACKTRACE
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bool
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depends on DEBUG_KERNEL
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depends on STACKTRACE_SUPPORT
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config DEBUG_KOBJECT
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bool "kobject debugging"
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depends on DEBUG_KERNEL
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help
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If you say Y here, some extra kobject debugging messages will be sent
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to the syslog.
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config DEBUG_HIGHMEM
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bool "Highmem debugging"
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depends on DEBUG_KERNEL && HIGHMEM
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help
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This options enables addition error checking for high memory systems.
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Disable for production systems.
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config DEBUG_BUGVERBOSE
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bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
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depends on BUG
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depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || FRV || SUPERH || GENERIC_BUG || BLACKFIN
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default !EMBEDDED
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help
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Say Y here to make BUG() panics output the file name and line number
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of the BUG call as well as the EIP and oops trace. This aids
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debugging but costs about 70-100K of memory.
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config DEBUG_INFO
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bool "Compile the kernel with debug info"
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depends on DEBUG_KERNEL
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help
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If you say Y here the resulting kernel image will include
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debugging info resulting in a larger kernel image.
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This adds debug symbols to the kernel and modules (gcc -g), and
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is needed if you intend to use kernel crashdump or binary object
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tools like crash, kgdb, LKCD, gdb, etc on the kernel.
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Say Y here only if you plan to debug the kernel.
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If unsure, say N.
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config DEBUG_VM
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bool "Debug VM"
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depends on DEBUG_KERNEL
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help
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Enable this to turn on extended checks in the virtual-memory system
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that may impact performance.
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If unsure, say N.
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config DEBUG_LIST
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bool "Debug linked list manipulation"
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depends on DEBUG_KERNEL
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help
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Enable this to turn on extended checks in the linked-list
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walking routines.
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If unsure, say N.
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config DEBUG_SG
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bool "Debug SG table operations"
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depends on DEBUG_KERNEL
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help
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Enable this to turn on checks on scatter-gather tables. This can
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help find problems with drivers that do not properly initialize
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their sg tables.
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If unsure, say N.
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config FRAME_POINTER
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bool "Compile the kernel with frame pointers"
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depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || AVR32 || SUPERH || BLACKFIN)
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default y if DEBUG_INFO && UML
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help
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If you say Y here the resulting kernel image will be slightly larger
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and slower, but it might give very useful debugging information on
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some architectures or if you use external debuggers.
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If you don't debug the kernel, you can say N.
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config FORCED_INLINING
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bool "Force gcc to inline functions marked 'inline'"
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depends on DEBUG_KERNEL
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default y
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help
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This option determines if the kernel forces gcc to inline the functions
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developers have marked 'inline'. Doing so takes away freedom from gcc to
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do what it thinks is best, which is desirable for the gcc 3.x series of
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compilers. The gcc 4.x series have a rewritten inlining algorithm and
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disabling this option will generate a smaller kernel there. Hopefully
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this algorithm is so good that allowing gcc4 to make the decision can
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become the default in the future, until then this option is there to
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test gcc for this.
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config BOOT_PRINTK_DELAY
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bool "Delay each boot printk message by N milliseconds"
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depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
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help
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This build option allows you to read kernel boot messages
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by inserting a short delay after each one. The delay is
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specified in milliseconds on the kernel command line,
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using "boot_delay=N".
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It is likely that you would also need to use "lpj=M" to preset
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the "loops per jiffie" value.
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See a previous boot log for the "lpj" value to use for your
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system, and then set "lpj=M" before setting "boot_delay=N".
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NOTE: Using this option may adversely affect SMP systems.
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I.e., processors other than the first one may not boot up.
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BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
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what it believes to be lockup conditions.
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config RCU_TORTURE_TEST
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tristate "torture tests for RCU"
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depends on DEBUG_KERNEL
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depends on m
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default n
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help
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This option provides a kernel module that runs torture tests
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on the RCU infrastructure. The kernel module may be built
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after the fact on the running kernel to be tested, if desired.
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Say M if you want the RCU torture tests to build as a module.
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Say N if you are unsure.
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config LKDTM
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tristate "Linux Kernel Dump Test Tool Module"
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depends on DEBUG_KERNEL
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depends on KPROBES
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default n
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help
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This module enables testing of the different dumping mechanisms by
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inducing system failures at predefined crash points.
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If you don't need it: say N
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Choose M here to compile this code as a module. The module will be
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called lkdtm.
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Documentation on how to use the module can be found in
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drivers/misc/lkdtm.c
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config FAULT_INJECTION
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bool "Fault-injection framework"
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depends on DEBUG_KERNEL
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help
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Provide fault-injection framework.
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For more details, see Documentation/fault-injection/.
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config FAILSLAB
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bool "Fault-injection capability for kmalloc"
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depends on FAULT_INJECTION
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help
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Provide fault-injection capability for kmalloc.
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config FAIL_PAGE_ALLOC
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bool "Fault-injection capabilitiy for alloc_pages()"
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depends on FAULT_INJECTION
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help
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Provide fault-injection capability for alloc_pages().
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config FAIL_MAKE_REQUEST
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bool "Fault-injection capability for disk IO"
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depends on FAULT_INJECTION
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help
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Provide fault-injection capability for disk IO.
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config FAULT_INJECTION_DEBUG_FS
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bool "Debugfs entries for fault-injection capabilities"
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depends on FAULT_INJECTION && SYSFS && DEBUG_FS
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help
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Enable configuration of fault-injection capabilities via debugfs.
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config FAULT_INJECTION_STACKTRACE_FILTER
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bool "stacktrace filter for fault-injection capabilities"
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depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
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depends on !X86_64
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select STACKTRACE
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select FRAME_POINTER
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help
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Provide stacktrace filter for fault-injection capabilities
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config LATENCYTOP
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bool "Latency measuring infrastructure"
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select FRAME_POINTER if !MIPS
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select KALLSYMS
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select KALLSYMS_ALL
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select STACKTRACE
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select SCHEDSTATS
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select SCHED_DEBUG
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depends on X86 || X86_64
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help
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Enable this option if you want to use the LatencyTOP tool
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to find out which userspace is blocking on what kernel operations.
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source "samples/Kconfig"
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