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.
+ in kernel startup. Or add printk.time=1 at boot-time.
+ See Documentation/kernel-parameters.txt
+
+config DEFAULT_MESSAGE_LOGLEVEL
+ int "Default message log level (1-7)"
+ range 1 7
+ default "4"
+ help
+ Default log level for printk statements with no specified priority.
+
+ This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
+ that are auditing their logs closely may want to set it to a lower
+ priority.
config ENABLE_WARN_DEPRECATED
bool "Enable __deprecated logic"
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
config DEBUG_SECTION_MISMATCH
bool "Enable full Section mismatch analysis"
- depends on UNDEFINED || (BLACKFIN)
- default y
- # This option is on purpose disabled for now.
- # 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
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
+ During linktime or runtime, some sections are dropped;
+ any use of code/data previously in these sections would
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)
+ In the code, functions and variables are annotated with
+ __init, __devinit, etc. (see the 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 section mismatch analysis is always performed after a full
+ kernel build, and enabling this option causes the following
+ additional steps to occur:
+ - Add the option -fno-inline-functions-called-once to gcc commands.
+ When inlining a function annotated with __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
+ This option tells gcc to inline less (but it does result in
+ a larger kernel).
+ - Run the section mismatch analysis for each module/built-in.o file.
+ 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.
+ tells where the mismatch happens much closer to the
+ source. The drawback is that the same mismatch is
+ reported at least twice.
+ - Enable verbose reporting from modpost in order to help resolve
+ the section mismatches that are reported.
config DEBUG_KERNEL
bool "Kernel debugging"
hard and soft lockups.
Softlockups are bugs that cause the kernel to loop in kernel
- mode for more than 60 seconds, without giving other tasks a
+ mode for more than 20 seconds, without giving other tasks a
chance to run. The current stack trace is displayed upon
detection and the system will stay locked up.
Hardlockups are bugs that cause the CPU to loop in kernel mode
- for more than 60 seconds, without letting other interrupts have a
+ for more than 10 seconds, without letting other interrupts have a
chance to run. The current stack trace is displayed upon detection
and the system will stay locked up.
The overhead should be minimal. A periodic hrtimer runs to
- generate interrupts and kick the watchdog task every 10-12 seconds.
- An NMI is generated every 60 seconds or so to check for hardlockups.
+ generate interrupts and kick the watchdog task every 4 seconds.
+ An NMI is generated every 10 seconds or so to check for hardlockups.
+
+ The frequency of hrtimer and NMI events and the soft and hard lockup
+ thresholds can be controlled through the sysctl watchdog_thresh.
config HARDLOCKUP_DETECTOR
- def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI
+ def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
+ !HAVE_NMI_WATCHDOG
+
+config BOOTPARAM_HARDLOCKUP_PANIC
+ bool "Panic (Reboot) On Hard Lockups"
+ depends on LOCKUP_DETECTOR
+ help
+ Say Y here to enable the kernel to panic on "hard lockups",
+ which are bugs that cause the kernel to loop in kernel
+ mode with interrupts disabled for more than 10 seconds (configurable
+ using the watchdog_thresh sysctl).
+
+ Say N if unsure.
+
+config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
+ int
+ depends on LOCKUP_DETECTOR
+ range 0 1
+ default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
+ default 1 if BOOTPARAM_HARDLOCKUP_PANIC
config BOOTPARAM_SOFTLOCKUP_PANIC
bool "Panic (Reboot) On Soft Lockups"
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.
+ mode for more than 20 seconds (configurable using the watchdog_thresh
+ sysctl), 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
config DETECT_HUNG_TASK
bool "Detect Hung Tasks"
depends on DEBUG_KERNEL
- default DETECT_SOFTLOCKUP
+ default LOCKUP_DETECTOR
help
Say Y here to enable the kernel to detect "hung tasks",
which are bugs that cause the task to be stuck in
enabled then all held locks will also be reported. This
feature has negligible overhead.
+config DEFAULT_HUNG_TASK_TIMEOUT
+ int "Default timeout for hung task detection (in seconds)"
+ depends on DETECT_HUNG_TASK
+ default 120
+ help
+ This option controls the default timeout (in seconds) used
+ to determine when a task has become non-responsive and should
+ be considered hung.
+
+ It can be adjusted at runtime via the kernel.hung_task_timeout_secs
+ sysctl or by writing a value to
+ /proc/sys/kernel/hung_task_timeout_secs.
+
+ A timeout of 0 disables the check. The default is two minutes.
+ Keeping the default should be fine in most cases.
+
config BOOTPARAM_HUNG_TASK_PANIC
bool "Panic (Reboot) On Hung Tasks"
depends on DETECT_HUNG_TASK
config DEBUG_OBJECTS_RCU_HEAD
bool "Debug RCU callbacks objects"
- depends on DEBUG_OBJECTS && PREEMPT
+ depends on DEBUG_OBJECTS
help
Enable this to turn on debugging of RCU list heads (call_rcu() usage).
+config DEBUG_OBJECTS_PERCPU_COUNTER
+ bool "Debug percpu counter objects"
+ depends on DEBUG_OBJECTS
+ help
+ If you say Y here, additional code will be inserted into the
+ percpu counter routines to track the life time of percpu counter
+ objects and validate the percpu counter operations.
+
config DEBUG_OBJECTS_ENABLE_DEFAULT
int "debug_objects bootup default value (0-1)"
range 0 1
config SLUB_STATS
default n
bool "Enable SLUB performance statistics"
- depends on SLUB && SLUB_DEBUG && SYSFS
+ depends on SLUB && SYSFS
help
SLUB statistics are useful to debug SLUBs allocation behavior in
order find ways to optimize the allocator. This should never be
config DEBUG_KMEMLEAK
bool "Kernel memory leak detector"
- depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
- (X86 || ARM || PPC || S390 || SPARC64 || SUPERH || MICROBLAZE)
+ depends on DEBUG_KERNEL && EXPERIMENTAL && \
+ (X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE)
- select DEBUG_FS if SYSFS
+ select DEBUG_FS
select STACKTRACE if STACKTRACE_SUPPORT
select KALLSYMS
select CRC32
config DEBUG_KMEMLEAK_TEST
tristate "Simple test for the kernel memory leak detector"
- depends on DEBUG_KMEMLEAK
+ depends on DEBUG_KMEMLEAK && m
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.
+ This option enables a module that explicitly leaks memory.
If unsure, say N.
+config DEBUG_KMEMLEAK_DEFAULT_OFF
+ bool "Default kmemleak to off"
+ depends on DEBUG_KMEMLEAK
+ help
+ Say Y here to disable kmemleak by default. It can then be enabled
+ on the command line via kmemleak=on.
+
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
config DEBUG_SPINLOCK
bool "Spinlock and rw-lock debugging: basic checks"
depends on DEBUG_KERNEL
+ select UNINLINE_SPIN_UNLOCK
help
Say Y here and build SMP to catch missing spinlock initialization
and certain other kinds of spinlock errors commonly made. This is
select DEBUG_SPINLOCK
select DEBUG_MUTEXES
select DEBUG_LOCK_ALLOC
+ select TRACE_IRQFLAGS
default n
help
This feature enables the kernel to prove that all locking
disabling, allowing multiple RCU-lockdep warnings to be printed
on a single reboot.
+ Say Y to allow multiple RCU-lockdep warnings per boot.
+
+ Say N if you are unsure.
+
+config SPARSE_RCU_POINTER
+ bool "RCU debugging: sparse-based checks for pointer usage"
+ default n
+ help
+ This feature enables the __rcu sparse annotation for
+ RCU-protected pointers. This annotation will cause sparse
+ to flag any non-RCU used of annotated pointers. This can be
+ helpful when debugging RCU usage. Please note that this feature
+ is not intended to enforce code cleanliness; it is instead merely
+ a debugging aid.
+
+ Say Y to make sparse flag questionable use of RCU-protected pointers
+
Say N if you are unsure.
config LOCKDEP
of more runtime overhead.
config TRACE_IRQFLAGS
- depends on DEBUG_KERNEL
bool
- default y
- depends on TRACE_IRQFLAGS_SUPPORT
- depends on PROVE_LOCKING
+ help
+ Enables hooks to interrupt enabling and disabling for
+ either tracing or lock debugging.
-config DEBUG_SPINLOCK_SLEEP
- bool "Spinlock debugging: sleep-inside-spinlock checking"
+config DEBUG_ATOMIC_SLEEP
+ bool "Sleep inside atomic section checking"
+ select PREEMPT_COUNT
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.
+ noisy if they are called inside atomic sections: when a spinlock is
+ held, inside an rcu read side critical section, inside preempt disabled
+ sections, inside an interrupt, etc...
config DEBUG_LOCKING_API_SELFTESTS
bool "Locking API boot-time self-tests"
bool
depends on STACKTRACE_SUPPORT
+config DEBUG_STACK_USAGE
+ bool "Stack utilization instrumentation"
+ depends on DEBUG_KERNEL
+ help
+ Enables the display of the minimum amount of free stack which each
+ task has ever had available in the sysrq-T and sysrq-P debug output.
+
+ This option will slow down process creation somewhat.
+
config DEBUG_KOBJECT
bool "kobject debugging"
depends on DEBUG_KERNEL
Disable for production systems.
config DEBUG_BUGVERBOSE
- bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
+ bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
depends on BUG
depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
- FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
+ FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 || TILE
default y
help
Say Y here to make BUG() panics output the file name and line number
If unsure, say N.
config DEBUG_MEMORY_INIT
- bool "Debug memory initialisation" if EMBEDDED
- default !EMBEDDED
+ bool "Debug memory initialisation" if EXPERT
+ default !EXPERT
help
Enable this for additional checks during memory initialisation.
The sanity checks verify aspects of the VM such as the memory model
If unsure, say N.
+config TEST_LIST_SORT
+ bool "Linked list sorting test"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on 'list_sort()' function test. This test is
+ executed only once during system boot, so affects only boot time.
+
+ If unsure, say N.
+
config DEBUG_SG
bool "Debug SG table operations"
depends on DEBUG_KERNEL
#
# Select this config option from the architecture Kconfig, if it
-# it is preferred to always offer frame pointers as a config
+# is preferred to always offer frame pointers as a config
# option on the architecture (regardless of KERNEL_DEBUG):
#
config ARCH_WANT_FRAME_POINTERS
config FRAME_POINTER
bool "Compile the kernel with frame pointers"
depends on DEBUG_KERNEL && \
- (CRIS || M68K || M68KNOMMU || FRV || UML || \
+ (CRIS || M68K || FRV || UML || \
AVR32 || SUPERH || BLACKFIN || MN10300) || \
ARCH_WANT_FRAME_POINTERS
default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
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
+ BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
what it believes to be lockup conditions.
config RCU_TORTURE_TEST
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"
+config RCU_CPU_STALL_TIMEOUT
+ int "RCU CPU stall timeout in seconds"
depends on TREE_RCU || TREE_PREEMPT_RCU
- default y
+ range 3 300
+ default 60
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 N if you want to disable such checks.
-
- Say Y if you are unsure.
+ If a given RCU grace period extends more than the specified
+ number of seconds, a CPU stall warning is printed. If the
+ RCU grace period persists, additional CPU stall warnings are
+ printed at more widely spaced intervals.
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
+ depends on TREE_PREEMPT_RCU
default y
help
This option causes RCU to printk detailed per-task information
Say Y if you want to enable such checks.
+config RCU_CPU_STALL_INFO
+ bool "Print additional diagnostics on RCU CPU stall"
+ depends on (TREE_RCU || TREE_PREEMPT_RCU) && DEBUG_KERNEL
+ default n
+ help
+ For each stalled CPU that is aware of the current RCU grace
+ period, print out additional per-CPU diagnostic information
+ regarding scheduling-clock ticks, idle state, and,
+ for RCU_FAST_NO_HZ kernels, idle-entry state.
+
+ Say N if you are unsure.
+
+ Say Y if you want to enable such diagnostics.
+
+config RCU_TRACE
+ bool "Enable tracing for RCU"
+ depends on DEBUG_KERNEL
+ help
+ This option provides tracing in RCU which presents stats
+ in debugfs for debugging RCU implementation.
+
+ Say Y here if you want to enable RCU tracing
+ Say N if you are unsure.
+
config KPROBES_SANITY_TEST
bool "Kprobes sanity tests"
depends on DEBUG_KERNEL
To ensure that generic code follows the above rules, this
option forces all percpu variables to be defined as weak.
+config DEBUG_PER_CPU_MAPS
+ bool "Debug access to per_cpu maps"
+ depends on DEBUG_KERNEL
+ depends on SMP
+ help
+ Say Y to verify that the per_cpu map being accessed has
+ been set up. This adds a fair amount of code to kernel memory
+ and decreases performance.
+
+ Say N if unsure.
+
config LKDTM
tristate "Linux Kernel Dump Test Tool Module"
depends on DEBUG_FS
Only works with drivers that use the generic timeout handling,
for others it wont do anything.
+config FAIL_MMC_REQUEST
+ bool "Fault-injection capability for MMC IO"
+ select DEBUG_FS
+ depends on FAULT_INJECTION && MMC
+ help
+ Provide fault-injection capability for MMC IO.
+ This will make the mmc core return data errors. This is
+ useful to test the error handling in the mmc block device
+ and to test how the mmc host driver handles retries from
+ the block device.
+
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 if !PPC && !S390 && !MICROBLAZE
+ select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND
help
Provide stacktrace filter for fault-injection capabilities
config LATENCYTOP
bool "Latency measuring infrastructure"
- select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE
+ depends on HAVE_LATENCYTOP_SUPPORT
+ depends on DEBUG_KERNEL
+ depends on STACKTRACE_SUPPORT
+ depends on PROC_FS
+ select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND
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
- ---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
If unsure, say N.
+config ASYNC_RAID6_TEST
+ tristate "Self test for hardware accelerated raid6 recovery"
+ depends on ASYNC_RAID6_RECOV
+ select ASYNC_MEMCPY
+ ---help---
+ This is a one-shot self test that permutes through the
+ recovery of all the possible two disk failure scenarios for a
+ N-disk array. Recovery is performed with the asynchronous
+ raid6 recovery routines, and will optionally use an offload
+ engine if one is available.
+
+ If unsure, say N.
+
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
source "lib/Kconfig.kmemcheck"
+
+config TEST_KSTRTOX
+ tristate "Test kstrto*() family of functions at runtime"
Code Review / linux-2.6.git / blobdiff