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
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 !X86 && !MIPS && !PPC && !ARM_UNWIND
select KALLSYMS
select KALLSYMS_ALL
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
Say N if you are unsure.
-config DYNAMIC_PRINTK_DEBUG
- bool "Enable dynamic printk() call support"
+config DYNAMIC_DEBUG
+ bool "Enable dynamic printk() support"
default n
depends on PRINTK
+ depends on DEBUG_FS
select PRINTK_DEBUG
help
Compiles debug level messages into the kernel, which would not
otherwise be available at runtime. These messages can then be
- enabled/disabled on a per module basis. This mechanism implicitly
- enables all pr_debug() and dev_dbg() calls. The impact of this
- compile option is a larger kernel text size of about 2%.
+ 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 by the debugfs file,
- dynamic_printk/modules. This file contains a list of the modules that
- can be enabled. The format of the file is the module name, followed
- by a set of flags that can be enabled. The first flag is always the
- 'enabled' flag. For example:
+ 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:
- <module_name> <enabled=0/1>
- .
- .
- .
+ filename:lineno [module]function flags format
- <module_name> : Name of the module in which the debug call resides
- <enabled=0/1> : whether the messages are enabled or not
+ 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:
- snd_hda_intel enabled=0
- fixup enabled=0
- driver enabled=0
-
- Enable a module:
-
- $echo "set enabled=1 <module_name>" > dynamic_printk/modules
+ 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"
- Disable a module:
+ Example usage:
- $echo "set enabled=0 <module_name>" > dynamic_printk/modules
+ // 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 modules:
+ // enable all the messages in file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c +p' >
+ <debugfs>/dynamic_debug/ddebug
- $echo "set enabled=1 all" > dynamic_printk/modules
+ // enable all the messages in the NFS server module
+ nullarbor:~ # echo -n 'module nfsd +p' >
+ <debugfs>/dynamic_debug/ddebug
- Disable all modules:
+ // enable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process +p' >
+ <debugfs>/dynamic_debug/ddebug
- $echo "set enabled=0 all" > dynamic_printk/modules
+ // disable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process -p' >
+ <debugfs>/dynamic_debug/ddebug
- Finally, passing "dynamic_printk" at the command line enables
- debugging for all modules. This mode can be turned off via the above
- disable command.
+ See Documentation/dynamic-debug-howto.txt for additional information.
config DMA_API_DEBUG
bool "Enable debugging of DMA-API usage"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff