keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
unless you really know what this hack does.
+config STRIP_ASM_SYMS
+ bool "Strip assembler-generated symbols during link"
+ default n
+ help
+ Strip internal assembler-generated symbols during a link (symbols
+ that look like '.Lxxx') so they don't pollute the output of
+ get_wchan() and suchlike.
+
config UNUSED_SYMBOLS
bool "Enable unused/obsolete exported symbols"
default y if X86
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
+ # It will be enabled when we are down to a reasonable number
# of section mismatch warnings (< 10 for an allyesconfig build)
help
The section mismatch analysis checks if there are illegal
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
+config DETECT_HUNG_TASK
+ bool "Detect Hung Tasks"
+ depends on DEBUG_KERNEL
+ default DETECT_SOFTLOCKUP
+ help
+ Say Y here to enable the kernel to detect "hung tasks",
+ which are bugs that cause the task to be stuck in
+ uninterruptible "D" state indefinitiley.
+
+ When a hung task is detected, the kernel will print the
+ current stack trace (which you should report), but the
+ task will stay in uninterruptible state. If lockdep is
+ enabled then all held locks will also be reported. This
+ feature has negligible overhead.
+
+config BOOTPARAM_HUNG_TASK_PANIC
+ bool "Panic (Reboot) On Hung Tasks"
+ depends on DETECT_HUNG_TASK
+ help
+ Say Y here to enable the kernel to panic on "hung tasks",
+ which are bugs that cause the kernel to leave a task stuck
+ in uninterruptible "D" state.
+
+ The panic can be used in combination with panic_timeout,
+ to cause the system to reboot automatically after a
+ hung task has been detected. This feature is useful for
+ high-availability systems that have uptime guarantees and
+ where a hung tasks must be resolved ASAP.
+
+ Say N if unsure.
+
+config BOOTPARAM_HUNG_TASK_PANIC_VALUE
+ int
+ depends on DETECT_HUNG_TASK
+ range 0 1
+ default 0 if !BOOTPARAM_HUNG_TASK_PANIC
+ default 1 if BOOTPARAM_HUNG_TASK_PANIC
+
config SCHED_DEBUG
bool "Collect scheduler debugging info"
depends on DEBUG_KERNEL && PROC_FS
timer routines to track the life time of timer objects and
validate the timer operations.
+config DEBUG_OBJECTS_WORK
+ bool "Debug work objects"
+ depends on DEBUG_OBJECTS
+ help
+ If you say Y here, additional code will be inserted into the
+ work queue routines to track the life time of work objects and
+ validate the work operations.
+
+config DEBUG_OBJECTS_ENABLE_DEFAULT
+ int "debug_objects bootup default value (0-1)"
+ range 0 1
+ default "1"
+ depends on DEBUG_OBJECTS
+ help
+ Debug objects boot parameter default value
+
config DEBUG_SLAB
bool "Debug slab memory allocations"
- depends on DEBUG_KERNEL && SLAB
+ depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
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
config SLUB_DEBUG_ON
bool "SLUB debugging on by default"
- depends on SLUB && SLUB_DEBUG
+ depends on SLUB && SLUB_DEBUG && !KMEMCHECK
default n
help
Boot with debugging on by default. SLUB boots by default with
out which slabs are relevant to a particular load.
Try running: slabinfo -DA
+config DEBUG_KMEMLEAK
+ bool "Kernel memory leak detector"
+ depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
+ (X86 || ARM || PPC || S390 || SUPERH)
+
+ select DEBUG_FS if SYSFS
+ select STACKTRACE if STACKTRACE_SUPPORT
+ select KALLSYMS
+ select CRC32
+ help
+ Say Y here if you want to enable the memory leak
+ detector. The memory allocation/freeing is traced in a way
+ similar to the Boehm's conservative garbage collector, the
+ difference being that the orphan objects are not freed but
+ only shown in /sys/kernel/debug/kmemleak. Enabling this
+ feature will introduce an overhead to memory
+ allocations. See Documentation/kmemleak.txt for more
+ details.
+
+ Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
+ of finding leaks due to the slab objects poisoning.
+
+ In order to access the kmemleak file, debugfs needs to be
+ mounted (usually at /sys/kernel/debug).
+
+config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
+ int "Maximum kmemleak early log entries"
+ depends on DEBUG_KMEMLEAK
+ range 200 40000
+ default 400
+ help
+ Kmemleak must track all the memory allocations to avoid
+ reporting false positives. Since memory may be allocated or
+ freed before kmemleak is initialised, an early log buffer is
+ used to store these actions. If kmemleak reports "early log
+ buffer exceeded", please increase this value.
+
+config DEBUG_KMEMLEAK_TEST
+ tristate "Simple test for the kernel memory leak detector"
+ depends on DEBUG_KMEMLEAK
+ help
+ Say Y or M here to build a test for the kernel memory leak
+ detector. This option enables a module that explicitly leaks
+ memory.
+
+ If unsure, say N.
+
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
- depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
+ 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
For more details, see Documentation/lockdep-design.txt.
+config PROVE_RCU
+ bool "RCU debugging: prove RCU correctness"
+ depends on PROVE_LOCKING
+ default n
+ help
+ This feature enables lockdep extensions that check for correct
+ use of RCU APIs. This is currently under development. Say Y
+ if you want to debug RCU usage or help work on the PROVE_RCU
+ feature.
+
+ Say N if you are unsure.
+
config LOCKDEP
bool
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
select STACKTRACE
- select FRAME_POINTER if !X86 && !MIPS && !PPC
+ select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390
select KALLSYMS
select KALLSYMS_ALL
depends on BUG
depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
- default !EMBEDDED
+ default y
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
If unsure, say N.
+config DEBUG_NOMMU_REGIONS
+ bool "Debug the global anon/private NOMMU mapping region tree"
+ depends on DEBUG_KERNEL && !MMU
+ help
+ This option causes the global tree of anonymous and private mapping
+ regions to be regularly checked for invalid topology.
+
config DEBUG_WRITECOUNT
bool "Debug filesystem writers count"
depends on DEBUG_KERNEL
If unsure, say N.
+config DEBUG_NOTIFIERS
+ bool "Debug notifier call chains"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on sanity checking for notifier call chains.
+ This is most useful for kernel developers to make sure that
+ modules properly unregister themselves from notifier chains.
+ This is a relatively cheap check but if you care about maximum
+ performance, say N.
+
+config DEBUG_CREDENTIALS
+ bool "Debug credential management"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on some debug checking for credential
+ management. The additional code keeps track of the number of
+ pointers from task_structs to any given cred struct, and checks to
+ see that this number never exceeds the usage count of the cred
+ struct.
+
+ Furthermore, if SELinux is enabled, this also checks that the
+ security pointer in the cred struct is never seen to be invalid.
+
+ If unsure, say N.
+
+#
+# Select this config option from the architecture Kconfig, if it
+# it is preferred to always offer frame pointers as a config
+# option on the architecture (regardless of KERNEL_DEBUG):
+#
+config ARCH_WANT_FRAME_POINTERS
+ bool
+ help
+
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
+ (CRIS || M68K || M68KNOMMU || FRV || UML || \
+ AVR32 || SUPERH || BLACKFIN || MN10300) || \
+ ARCH_WANT_FRAME_POINTERS
+ default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
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.
+ If you say Y here the resulting kernel image will be slightly
+ larger and slower, but it gives very useful debugging information
+ in case of kernel bugs. (precise oopses/stacktraces/warnings)
config BOOT_PRINTK_DELAY
bool "Delay each boot printk message by N milliseconds"
config RCU_CPU_STALL_DETECTOR
bool "Check for stalled CPUs delaying RCU grace periods"
- depends on CLASSIC_RCU
- default n
+ depends on TREE_RCU || TREE_PREEMPT_RCU
+ default y
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 want to disable such checks.
+
+ Say Y if you are unsure.
+
+config RCU_CPU_STALL_VERBOSE
+ bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
+ depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU
+ default n
+ help
+ This option causes RCU to printk detailed per-task information
+ for any tasks that are stalling the current RCU grace period.
Say N if you are unsure.
+ Say Y if you want to enable such checks.
+
config KPROBES_SANITY_TEST
bool "Kprobes sanity tests"
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
Say N if you are unsure.
+config DEBUG_FORCE_WEAK_PER_CPU
+ bool "Force weak per-cpu definitions"
+ depends on DEBUG_KERNEL
+ help
+ s390 and alpha require percpu variables in modules to be
+ defined weak to work around addressing range issue which
+ puts the following two restrictions on percpu variable
+ definitions.
+
+ 1. percpu symbols must be unique whether static or not
+ 2. percpu variables can't be defined inside a function
+
+ To ensure that generic code follows the above rules, this
+ option forces all percpu variables to be defined as weak.
+
config LKDTM
tristate "Linux Kernel Dump Test Tool Module"
- depends on DEBUG_KERNEL
- depends on KPROBES
+ depends on DEBUG_FS
depends on BLOCK
default n
help
called lkdtm.
Documentation on how to use the module can be found in
- drivers/misc/lkdtm.c
+ Documentation/fault-injection/provoke-crashes.txt
config FAULT_INJECTION
bool "Fault-injection framework"
config FAILSLAB
bool "Fault-injection capability for kmalloc"
depends on FAULT_INJECTION
+ depends on SLAB || SLUB
help
Provide fault-injection capability for kmalloc.
depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
depends on !X86_64
select STACKTRACE
- select FRAME_POINTER if !PPC
+ select FRAME_POINTER if !PPC && !S390
help
Provide stacktrace filter for fault-injection capabilities
config LATENCYTOP
bool "Latency measuring infrastructure"
- select FRAME_POINTER if !MIPS && !PPC
+ select FRAME_POINTER if !MIPS && !PPC && !S390
select KALLSYMS
select KALLSYMS_ALL
select STACKTRACE
config SYSCTL_SYSCALL_CHECK
bool "Sysctl checks"
- depends on SYSCTL_SYSCALL
+ depends on SYSCTL
---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 mm/Kconfig.debug
source kernel/trace/Kconfig
config PROVIDE_OHCI1394_DMA_INIT
If unsure, say N.
-menuconfig BUILD_DOCSRC
+config BUILD_DOCSRC
bool "Build targets in Documentation/ tree"
depends on HEADERS_CHECK
help
Say N if you are unsure.
+config DYNAMIC_DEBUG
+ bool "Enable dynamic printk() support"
+ default n
+ depends on PRINTK
+ depends on DEBUG_FS
+ help
+
+ Compiles debug level messages into the kernel, which would not
+ otherwise be available at runtime. These messages can then be
+ enabled/disabled based on various levels of scope - per source file,
+ function, module, format string, and line number. 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 via the 'dynamic_debug/ddebug' file,
+ which is contained in the 'debugfs' filesystem. Thus, the debugfs
+ filesystem must first be mounted before making use of this feature.
+ We refer the control file as: <debugfs>/dynamic_debug/ddebug. This
+ file contains a list of the debug statements that can be enabled. The
+ format for each line of the file is:
+
+ filename:lineno [module]function flags format
+
+ filename : source file of the debug statement
+ lineno : line number of the debug statement
+ module : module that contains the debug statement
+ function : function that contains the debug statement
+ flags : 'p' means the line is turned 'on' for printing
+ format : the format used for the debug statement
+
+ From a live system:
+
+ nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug
+ # filename:lineno [module]function flags format
+ fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
+ fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
+ fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
+
+ Example usage:
+
+ // enable the message at line 1603 of file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
+ <debugfs>/dynamic_debug/ddebug
+
+ // enable all the messages in file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c +p' >
+ <debugfs>/dynamic_debug/ddebug
+
+ // enable all the messages in the NFS server module
+ nullarbor:~ # echo -n 'module nfsd +p' >
+ <debugfs>/dynamic_debug/ddebug
+
+ // enable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process +p' >
+ <debugfs>/dynamic_debug/ddebug
+
+ // disable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process -p' >
+ <debugfs>/dynamic_debug/ddebug
+
+ See Documentation/dynamic-debug-howto.txt for additional information.
+
+config DMA_API_DEBUG
+ bool "Enable debugging of DMA-API usage"
+ depends on HAVE_DMA_API_DEBUG
+ help
+ Enable this option to debug the use of the DMA API by device drivers.
+ With this option you will be able to detect common bugs in device
+ drivers like double-freeing of DMA mappings or freeing mappings that
+ were never allocated.
+ This option causes a performance degredation. Use only if you want
+ to debug device drivers. If unsure, say N.
+
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
+
+source "lib/Kconfig.kmemcheck"
Code Review / linux-2.6.git / blobdiff