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		0e11e342ba
		
	
	
	
	
		
			
			CONFIG_DEBUG_BLOCK_EXT_DEVT can break booting even on some modern distros. Add BIG FAT WARNING to keep people at a safe distance. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
		
			
				
	
	
		
			873 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			873 lines
		
	
	
		
			30 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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| 
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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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| 
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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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| 
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| config FRAME_WARN
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| 	int "Warn for stack frames larger than (needs gcc 4.4)"
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| 	range 0 8192
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| 	default 1024 if !64BIT
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| 	default 2048 if 64BIT
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| 	help
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| 	  Tell gcc to warn at build time for stack frames larger than this.
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| 	  Setting this too low will cause a lot of warnings.
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| 	  Setting it to 0 disables the warning.
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| 	  Requires gcc 4.4
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| 
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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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| 
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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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| 
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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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| 
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| 	  For detailed documentation on the debugfs API, see
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| 	  Documentation/DocBook/filesystems.
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| 
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| 	  If unsure, say N.
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| 
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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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| 
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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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| 
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| config DEBUG_SECTION_MISMATCH
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| 	bool "Enable full Section mismatch analysis"
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| 	depends on UNDEFINED
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| 	# This option is on purpose disabled for now.
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| 	# It will be enabled when we are down to a resonable number
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| 	# of section mismatch warnings (< 10 for an allyesconfig build)
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| 	help
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| 	  The section mismatch analysis checks if there are illegal
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| 	  references from one section to another section.
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| 	  Linux will during link or during runtime drop some sections
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| 	  and any use of code/data previously in these sections will
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| 	  most likely result in an oops.
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| 	  In the code functions and variables are annotated with
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| 	  __init, __devinit etc. (see full list in include/linux/init.h)
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| 	  which results in the code/data being placed in specific sections.
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| 	  The section mismatch analysis is always done after a full
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| 	  kernel build but enabling this option will in addition
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| 	  do the following:
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| 	  - Add the option -fno-inline-functions-called-once to gcc
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| 	    When inlining a function annotated __init in a non-init
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| 	    function we would lose the section information and thus
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| 	    the analysis would not catch the illegal reference.
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| 	    This option tells gcc to inline less but will also
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| 	    result in a larger kernel.
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| 	  - Run the section mismatch analysis for each module/built-in.o
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| 	    When we run the section mismatch analysis on vmlinux.o we
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| 	    lose valueble information about where the mismatch was
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| 	    introduced.
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| 	    Running the analysis for each module/built-in.o file
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| 	    will tell where the mismatch happens much closer to the
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| 	    source. The drawback is that we will report the same
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| 	    mismatch at least twice.
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| 	  - Enable verbose reporting from modpost to help solving
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| 	    the section mismatches reported.
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| 
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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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| 
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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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| 
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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 60 seconds, without giving other tasks a
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| 	  chance to run.
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| 
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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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| 
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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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| 
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| config BOOTPARAM_SOFTLOCKUP_PANIC
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| 	bool "Panic (Reboot) On Soft Lockups"
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| 	depends on DETECT_SOFTLOCKUP
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| 	help
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| 	  Say Y here to enable the kernel to panic on "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 60 seconds, without giving other tasks a
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| 	  chance to run.
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| 
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| 	  The panic can be used in combination with panic_timeout,
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| 	  to cause the system to reboot automatically after a
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| 	  lockup has been detected. This feature is useful for
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| 	  high-availability systems that have uptime guarantees and
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| 	  where a lockup must be resolved ASAP.
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| 
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| 	  Say N if unsure.
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| 
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| config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
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| 	int
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| 	depends on DETECT_SOFTLOCKUP
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| 	range 0 1
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| 	default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
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| 	default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
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| 
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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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| 
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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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| 
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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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| 
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| config DEBUG_OBJECTS
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| 	bool "Debug object operations"
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| 	depends on DEBUG_KERNEL
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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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| 	  kernel to track the life time of various objects and validate
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| 	  the operations on those objects.
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| 
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| config DEBUG_OBJECTS_SELFTEST
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| 	bool "Debug objects selftest"
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| 	depends on DEBUG_OBJECTS
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| 	help
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| 	  This enables the selftest of the object debug code.
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| 
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| config DEBUG_OBJECTS_FREE
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| 	bool "Debug objects in freed memory"
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| 	depends on DEBUG_OBJECTS
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| 	help
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| 	  This enables checks whether a k/v free operation frees an area
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| 	  which contains an object which has not been deactivated
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| 	  properly. This can make kmalloc/kfree-intensive workloads
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| 	  much slower.
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| 
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| config DEBUG_OBJECTS_TIMERS
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| 	bool "Debug timer objects"
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| 	depends on DEBUG_OBJECTS
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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 track the life time of timer objects and
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| 	  validate the timer operations.
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| 
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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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| 
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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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| 
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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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| 
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| config SLUB_STATS
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| 	default n
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| 	bool "Enable SLUB performance statistics"
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| 	depends on SLUB && SLUB_DEBUG && SYSFS
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| 	help
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| 	  SLUB statistics are useful to debug SLUBs allocation behavior in
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| 	  order find ways to optimize the allocator. This should never be
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| 	  enabled for production use since keeping statistics slows down
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| 	  the allocator by a few percentage points. The slabinfo command
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| 	  supports the determination of the most active slabs to figure
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| 	  out which slabs are relevant to a particular load.
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| 	  Try running: slabinfo -DA
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 	 For more details, see Documentation/lockdep-design.txt.
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| 
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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 && !PPC
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| 	select KALLSYMS
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| 	select KALLSYMS_ALL
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| 
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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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| 
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| 	 For more details, see Documentation/lockstat.txt
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| config STACKTRACE
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| 	bool
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| 	depends on STACKTRACE_SUPPORT
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| 
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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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| 
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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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| 
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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 || \
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| 		   FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
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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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| 
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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
 | |
|           If you say Y here the resulting kernel image will include
 | |
| 	  debugging info resulting in a larger kernel image.
 | |
| 	  This adds debug symbols to the kernel and modules (gcc -g), and
 | |
| 	  is needed if you intend to use kernel crashdump or binary object
 | |
| 	  tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 | |
| 	  Say Y here only if you plan to debug the kernel.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config DEBUG_VM
 | |
| 	bool "Debug VM"
 | |
| 	depends on DEBUG_KERNEL
 | |
| 	help
 | |
| 	  Enable this to turn on extended checks in the virtual-memory system
 | |
|           that may impact performance.
 | |
| 
 | |
| 	  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_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
 | |
| 	help
 | |
| 	  Enable this to turn on extended checks in the linked-list
 | |
| 	  walking routines.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| config DEBUG_SG
 | |
| 	bool "Debug SG table operations"
 | |
| 	depends on DEBUG_KERNEL
 | |
| 	help
 | |
| 	  Enable this to turn on checks on scatter-gather tables. This can
 | |
| 	  help find problems with drivers that do not properly initialize
 | |
| 	  their sg tables.
 | |
| 
 | |
| 	  If unsure, say N.
 | |
| 
 | |
| 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
 | |
| 	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.
 | |
| 
 | |
| config BOOT_PRINTK_DELAY
 | |
| 	bool "Delay each boot printk message by N milliseconds"
 | |
| 	depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
 | |
| 	help
 | |
| 	  This build option allows you to read kernel boot messages
 | |
| 	  by inserting a short delay after each one.  The delay is
 | |
| 	  specified in milliseconds on the kernel command line,
 | |
| 	  using "boot_delay=N".
 | |
| 
 | |
| 	  It is likely that you would also need to use "lpj=M" to preset
 | |
| 	  the "loops per jiffie" value.
 | |
| 	  See a previous boot log for the "lpj" value to use for your
 | |
| 	  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
 | |
| 	  what it believes to be lockup conditions.
 | |
| 
 | |
| config RCU_TORTURE_TEST
 | |
| 	tristate "torture tests for RCU"
 | |
| 	depends on DEBUG_KERNEL
 | |
| 	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
 | |
| 	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
 | |
| 	depends on KPROBES
 | |
| 	default n
 | |
| 	help
 | |
| 	  This option provides for testing basic kprobes functionality on
 | |
| 	  boot. A sample kprobe, jprobe and kretprobe are inserted and
 | |
| 	  verified for functionality.
 | |
| 
 | |
| 	  Say N if you are unsure.
 | |
| 
 | |
| config BACKTRACE_SELF_TEST
 | |
| 	tristate "Self test for the backtrace code"
 | |
| 	depends on DEBUG_KERNEL
 | |
| 	default n
 | |
| 	help
 | |
| 	  This option provides a kernel module that can be used to test
 | |
| 	  the kernel stack backtrace code. This option is not useful
 | |
| 	  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
 | |
| 	inducing system failures at predefined crash points.
 | |
| 	If you don't need it: say N
 | |
| 	Choose M here to compile this code as a module. The module will be
 | |
| 	called lkdtm.
 | |
| 
 | |
| 	Documentation on how to use the module can be found in
 | |
| 	drivers/misc/lkdtm.c
 | |
| 
 | |
| config FAULT_INJECTION
 | |
| 	bool "Fault-injection framework"
 | |
| 	depends on DEBUG_KERNEL
 | |
| 	help
 | |
| 	  Provide fault-injection framework.
 | |
| 	  For more details, see Documentation/fault-injection/.
 | |
| 
 | |
| config FAILSLAB
 | |
| 	bool "Fault-injection capability for kmalloc"
 | |
| 	depends on FAULT_INJECTION
 | |
| 	help
 | |
| 	  Provide fault-injection capability for kmalloc.
 | |
| 
 | |
| config FAIL_PAGE_ALLOC
 | |
| 	bool "Fault-injection capabilitiy for alloc_pages()"
 | |
| 	depends on FAULT_INJECTION
 | |
| 	help
 | |
| 	  Provide fault-injection capability for alloc_pages().
 | |
| 
 | |
| config FAIL_MAKE_REQUEST
 | |
| 	bool "Fault-injection capability for disk IO"
 | |
| 	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
 | |
| 	help
 | |
| 	  Enable configuration of fault-injection capabilities via debugfs.
 | |
| 
 | |
| config FAULT_INJECTION_STACKTRACE_FILTER
 | |
| 	bool "stacktrace filter for fault-injection capabilities"
 | |
| 	depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
 | |
| 	depends on !X86_64
 | |
| 	select STACKTRACE
 | |
| 	select FRAME_POINTER if !PPC
 | |
| 	help
 | |
| 	  Provide stacktrace filter for fault-injection capabilities
 | |
| 
 | |
| config LATENCYTOP
 | |
| 	bool "Latency measuring infrastructure"
 | |
| 	select FRAME_POINTER if !MIPS && !PPC
 | |
| 	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_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 kernel/trace/Kconfig
 | |
| 
 | |
| config PROVIDE_OHCI1394_DMA_INIT
 | |
| 	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
 | |
| 	  on boot and the crashing machine has a FireWire port, you can use
 | |
| 	  this feature to remotely access the memory of the crashed machine
 | |
| 	  over FireWire. This employs remote DMA as part of the OHCI1394
 | |
| 	  specification which is now the standard for FireWire controllers.
 | |
| 
 | |
| 	  With remote DMA, you can monitor the printk buffer remotely using
 | |
| 	  firescope and access all memory below 4GB using fireproxy from gdb.
 | |
| 	  Even controlling a kernel debugger is possible using remote DMA.
 | |
| 
 | |
| 	  Usage:
 | |
| 
 | |
| 	  If ohci1394_dma=early is used as boot parameter, it will initialize
 | |
| 	  all OHCI1394 controllers which are found in the PCI config space.
 | |
| 
 | |
| 	  As all changes to the FireWire bus such as enabling and disabling
 | |
| 	  devices cause a bus reset and thereby disable remote DMA for all
 | |
| 	  devices, be sure to have the cable plugged and FireWire enabled on
 | |
| 	  the debugging host before booting the debug target for debugging.
 | |
| 
 | |
| 	  This code (~1k) is freed after boot. By then, the firewire stack
 | |
| 	  in charge of the OHCI-1394 controllers should be used instead.
 | |
| 
 | |
| 	  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.
 | |
| 
 | |
| menuconfig 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_PRINTK_DEBUG
 | |
| 	bool "Enable dynamic printk() call support"
 | |
| 	default n
 | |
| 	depends on PRINTK
 | |
| 	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%.
 | |
| 
 | |
| 	  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:
 | |
| 
 | |
| 		<module_name> <enabled=0/1>
 | |
| 				.
 | |
| 				.
 | |
| 				.
 | |
| 
 | |
| 	  <module_name> : Name of the module in which the debug call resides
 | |
| 	  <enabled=0/1> : whether the messages are enabled or not
 | |
| 
 | |
| 	  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
 | |
| 
 | |
| 	  Disable a module:
 | |
| 
 | |
| 	  	$echo "set enabled=0 <module_name>" > dynamic_printk/modules
 | |
| 
 | |
| 	  Enable all modules:
 | |
| 
 | |
| 		$echo "set enabled=1 all" > dynamic_printk/modules
 | |
| 
 | |
| 	  Disable all modules:
 | |
| 
 | |
| 		$echo "set enabled=0 all" > dynamic_printk/modules
 | |
| 
 | |
| 	  Finally, passing "dynamic_printk" at the command line enables
 | |
| 	  debugging for all modules. This mode can be turned off via the above
 | |
| 	  disable command.
 | |
| 
 | |
| source "samples/Kconfig"
 | |
| 
 | |
| source "lib/Kconfig.kgdb"
 |