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
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
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 10 seconds, without giving other tasks a
+ 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
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 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
(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_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
config SLUB_STATS
default n
bool "Enable SLUB performance statistics"
- depends on SLUB
+ 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
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 && (X86 || ARM) && \
+ !MEMORY_HOTPLUG
+ select DEBUG_SLAB if SLAB
+ select SLUB_DEBUG if SLUB
+ select DEBUG_FS if SYSFS
+ select STACKTRACE if STACKTRACE_SUPPORT
+ select KALLSYMS
+ 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.
+
+ In order to access the kmemleak file, debugfs needs to be
+ mounted (usually at /sys/kernel/debug).
+
+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)
This feature allows mutex semantics violations to be detected and
reported.
-config DEBUG_SEMAPHORE
- bool "Semaphore debugging"
- depends on DEBUG_KERNEL
- depends on ALPHA || FRV
- default n
- help
- If you say Y here then semaphore processing will issue lots of
- verbose debugging messages. If you suspect a semaphore problem or a
- kernel hacker asks for this option then say Y. Otherwise say N.
-
config DEBUG_LOCK_ALLOC
bool "Lock debugging: detect incorrect freeing of live locks"
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
bool
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
select STACKTRACE
- select FRAME_POINTER if !X86 && !MIPS
+ select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND && !S390
select KALLSYMS
select KALLSYMS_ALL
config STACKTRACE
bool
- depends on DEBUG_KERNEL
depends on STACKTRACE_SUPPORT
config DEBUG_KOBJECT
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_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
+ 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
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.
+
+#
+# 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_TORTURE_TEST
tristate "torture tests for RCU"
depends on DEBUG_KERNEL
- depends on m
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 || TREE_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
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
config FAILSLAB
bool "Fault-injection capability for kmalloc"
depends on FAULT_INJECTION
+ depends on SLAB || SLUB
help
Provide fault-injection capability for kmalloc.
config FAIL_MAKE_REQUEST
bool "Fault-injection capability for disk IO"
- depends on FAULT_INJECTION
+ 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
depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
depends on !X86_64
select STACKTRACE
- select FRAME_POINTER
+ 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
+ select FRAME_POINTER if !MIPS && !PPC && !S390
select KALLSYMS
select KALLSYMS_ALL
select STACKTRACE
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 mm/Kconfig.debug
+source kernel/trace/Kconfig
+
config PROVIDE_OHCI1394_DMA_INIT
- bool "Provide code for enabling DMA over FireWire early on boot"
+ 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
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.
+
+config 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_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"