2005-04-16 22:20:36 +00:00
|
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|
|
config PRINTK_TIME
|
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|
|
bool "Show timing information on printks"
|
2006-12-07 04:36:38 +00:00
|
|
|
depends on PRINTK
|
2005-04-16 22:20:36 +00:00
|
|
|
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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|
2007-10-25 08:06:13 +00:00
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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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|
2006-08-15 05:43:18 +00:00
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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.
|
2005-04-16 22:20:36 +00:00
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2008-02-22 14:15:03 +00:00
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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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|
2005-04-16 22:20:36 +00:00
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|
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config MAGIC_SYSRQ
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|
|
bool "Magic SysRq key"
|
2006-01-10 04:54:51 +00:00
|
|
|
depends on !UML
|
2005-04-16 22:20:36 +00:00
|
|
|
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
|
|
|
|
|
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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|
|
|
2009-09-18 19:49:22 +00:00
|
|
|
config STRIP_ASM_SYMS
|
|
|
|
|
bool "Strip assembler-generated symbols during link"
|
|
|
|
|
default n
|
|
|
|
|
help
|
|
|
|
|
Strip internal assembler-generated symbols during a link (symbols
|
|
|
|
|
that look like '.Lxxx') so they don't pollute the output of
|
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|
|
get_wchan() and suchlike.
|
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|
|
|
2006-06-28 11:26:45 +00:00
|
|
|
config UNUSED_SYMBOLS
|
|
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|
|
bool "Enable unused/obsolete exported symbols"
|
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|
|
default y if X86
|
|
|
|
|
help
|
|
|
|
|
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
|
|
|
|
|
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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|
|
2006-12-10 10:18:37 +00:00
|
|
|
config DEBUG_FS
|
|
|
|
|
bool "Debug Filesystem"
|
|
|
|
|
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
|
|
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|
|
write to these files.
|
|
|
|
|
|
2008-05-19 22:06:00 +00:00
|
|
|
For detailed documentation on the debugfs API, see
|
|
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|
|
Documentation/DocBook/filesystems.
|
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|
|
2006-12-10 10:18:37 +00:00
|
|
|
If unsure, say N.
|
|
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|
|
config HEADERS_CHECK
|
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|
|
bool "Run 'make headers_check' when building vmlinux"
|
|
|
|
|
depends on !UML
|
|
|
|
|
help
|
|
|
|
|
This option will extract the user-visible kernel headers whenever
|
|
|
|
|
building the kernel, and will run basic sanity checks on them to
|
|
|
|
|
ensure that exported files do not attempt to include files which
|
|
|
|
|
were not exported, etc.
|
|
|
|
|
|
|
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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
|
|
|
|
|
exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
|
|
|
|
|
your build tree), to make sure they're suitable.
|
|
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|
|
|
2008-01-21 20:31:44 +00:00
|
|
|
config DEBUG_SECTION_MISMATCH
|
|
|
|
|
bool "Enable full Section mismatch analysis"
|
|
|
|
|
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
|
|
|
|
|
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)
|
2008-01-30 10:13:23 +00:00
|
|
|
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
|
2008-01-21 20:31:44 +00:00
|
|
|
do the following:
|
|
|
|
|
- Add the option -fno-inline-functions-called-once to gcc
|
|
|
|
|
When inlining a function annotated __init in a non-init
|
2008-01-30 10:13:23 +00:00
|
|
|
function we would lose the section information and thus
|
2008-01-21 20:31:44 +00:00
|
|
|
the analysis would not catch the illegal reference.
|
2008-01-30 10:13:23 +00:00
|
|
|
This option tells gcc to inline less but will also
|
2008-01-21 20:31:44 +00:00
|
|
|
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
|
2008-01-30 10:13:23 +00:00
|
|
|
lose valueble information about where the mismatch was
|
2008-01-21 20:31:44 +00:00
|
|
|
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.
|
2008-01-24 20:12:37 +00:00
|
|
|
- Enable verbose reporting from modpost to help solving
|
|
|
|
|
the section mismatches reported.
|
2008-01-21 20:31:44 +00:00
|
|
|
|
2006-01-10 04:54:51 +00:00
|
|
|
config DEBUG_KERNEL
|
|
|
|
|
bool "Kernel debugging"
|
|
|
|
|
help
|
|
|
|
|
Say Y here if you are developing drivers or trying to debug and
|
|
|
|
|
identify kernel problems.
|
|
|
|
|
|
2007-02-12 08:52:00 +00:00
|
|
|
config DEBUG_SHIRQ
|
|
|
|
|
bool "Debug shared IRQ handlers"
|
|
|
|
|
depends on DEBUG_KERNEL && GENERIC_HARDIRQS
|
|
|
|
|
help
|
|
|
|
|
Enable this to generate a spurious interrupt as soon as a shared
|
|
|
|
|
interrupt handler is registered, and just before one is deregistered.
|
|
|
|
|
Drivers ought to be able to handle interrupts coming in at those
|
|
|
|
|
points; some don't and need to be caught.
|
|
|
|
|
|
2010-05-07 21:11:44 +00:00
|
|
|
config LOCKUP_DETECTOR
|
|
|
|
|
bool "Detect Hard and Soft Lockups"
|
2006-10-11 08:20:44 +00:00
|
|
|
depends on DEBUG_KERNEL && !S390
|
2005-09-06 22:16:27 +00:00
|
|
|
help
|
2010-05-07 21:11:44 +00:00
|
|
|
Say Y here to enable the kernel to act as a watchdog to detect
|
|
|
|
|
hard and soft lockups.
|
|
|
|
|
|
|
|
|
|
Softlockups are bugs that cause the kernel to loop in kernel
|
2008-05-12 19:21:04 +00:00
|
|
|
mode for more than 60 seconds, without giving other tasks a
|
2010-05-07 21:11:44 +00:00
|
|
|
chance to run. The current stack trace is displayed upon
|
|
|
|
|
detection and the system will stay locked up.
|
2005-09-06 22:16:27 +00:00
|
|
|
|
2010-05-07 21:11:44 +00:00
|
|
|
Hardlockups are bugs that cause the CPU to loop in kernel mode
|
|
|
|
|
for more than 60 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.
|
2005-09-06 22:16:27 +00:00
|
|
|
|
2010-05-07 21:11:44 +00:00
|
|
|
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.
|
2005-09-06 22:16:27 +00:00
|
|
|
|
2010-05-15 21:15:20 +00:00
|
|
|
config HARDLOCKUP_DETECTOR
|
x86, nmi_watchdog: Remove ARCH_HAS_NMI_WATCHDOG and rely on CONFIG_HARDLOCKUP_DETECTOR
The x86 arch has shifted its use of the nmi_watchdog from a
local implementation to the global one provide by
kernel/watchdog.c. This shift has caused a whole bunch of
compile problems under different config options. I attempt to
simplify things with the patch below.
In order to simplify things, I had to come to terms with the
meaning of two terms ARCH_HAS_NMI_WATCHDOG and
CONFIG_HARDLOCKUP_DETECTOR. Basically they mean the same thing,
the former on a local level and the latter on a global level.
With the old x86 nmi watchdog gone, there is no need to rely on
defining the ARCH_HAS_NMI_WATCHDOG variable because it doesn't
make sense any more. x86 will now use the global
implementation.
The changes below do a few things. First it changes the few
places that relied on ARCH_HAS_NMI_WATCHDOG to use
CONFIG_X86_LOCAL_APIC (the former was an alias for the latter
anyway, so nothing unusual here). Those pieces of code were
relying more on local apic functionality the nmi watchdog
functionality, so the change should make sense.
Second, I removed the x86 implementation of
touch_nmi_watchdog(). It isn't need now, instead x86 will rely
on kernel/watchdog.c's implementation.
Third, I removed the #define ARCH_HAS_NMI_WATCHDOG itself from
x86. And tweaked the include/linux/nmi.h file to tell users to
look for an externally defined touch_nmi_watchdog in the case of
ARCH_HAS_NMI_WATCHDOG _or_ CONFIG_HARDLOCKUP_DETECTOR. This
changes removes some of the ugliness in that file.
Finally, I added a Kconfig dependency for
CONFIG_HARDLOCKUP_DETECTOR that said you can't have
ARCH_HAS_NMI_WATCHDOG _and_ CONFIG_HARDLOCKUP_DETECTOR. You can
only have one nmi_watchdog.
Tested with
ARCH=i386: allnoconfig, defconfig, allyesconfig, (various broken
configs) ARCH=x86_64: allnoconfig, defconfig, allyesconfig,
(various broken configs)
Hopefully, after this patch I won't get any more compile broken
emails. :-)
v3:
changed a couple of 'linux/nmi.h' -> 'asm/nmi.h' to pick-up correct function
prototypes when CONFIG_HARDLOCKUP_DETECTOR is not set.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1293044403-14117-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 19:00:03 +00:00
|
|
|
def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
|
|
|
|
|
!ARCH_HAS_NMI_WATCHDOG
|
2005-09-06 22:16:27 +00:00
|
|
|
|
2011-03-22 23:34:16 +00:00
|
|
|
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 60 seconds.
|
|
|
|
|
|
|
|
|
|
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
|
|
|
|
|
|
2008-05-12 19:21:04 +00:00
|
|
|
config BOOTPARAM_SOFTLOCKUP_PANIC
|
|
|
|
|
bool "Panic (Reboot) On Soft Lockups"
|
2010-05-12 22:27:20 +00:00
|
|
|
depends on LOCKUP_DETECTOR
|
2008-05-12 19:21:04 +00:00
|
|
|
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
|
2010-05-15 20:30:22 +00:00
|
|
|
depends on LOCKUP_DETECTOR
|
2008-05-12 19:21:04 +00:00
|
|
|
range 0 1
|
|
|
|
|
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
|
|
|
|
|
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
|
|
|
|
|
|
2009-01-15 19:08:40 +00:00
|
|
|
config DETECT_HUNG_TASK
|
|
|
|
|
bool "Detect Hung Tasks"
|
|
|
|
|
depends on DEBUG_KERNEL
|
2009-04-07 06:55:36 +00:00
|
|
|
default DETECT_SOFTLOCKUP
|
2009-01-15 19:08:40 +00:00
|
|
|
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
|
|
|
|
|
|
2007-07-09 16:52:00 +00:00
|
|
|
config SCHED_DEBUG
|
|
|
|
|
bool "Collect scheduler debugging info"
|
|
|
|
|
depends on DEBUG_KERNEL && PROC_FS
|
|
|
|
|
default y
|
|
|
|
|
help
|
|
|
|
|
If you say Y here, the /proc/sched_debug file will be provided
|
|
|
|
|
that can help debug the scheduler. The runtime overhead of this
|
|
|
|
|
option is minimal.
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config SCHEDSTATS
|
|
|
|
|
bool "Collect scheduler statistics"
|
|
|
|
|
depends on DEBUG_KERNEL && PROC_FS
|
|
|
|
|
help
|
|
|
|
|
If you say Y here, additional code will be inserted into the
|
|
|
|
|
scheduler and related routines to collect statistics about
|
|
|
|
|
scheduler behavior and provide them in /proc/schedstat. These
|
|
|
|
|
stats may be useful for both tuning and debugging the scheduler
|
|
|
|
|
If you aren't debugging the scheduler or trying to tune a specific
|
|
|
|
|
application, you can say N to avoid the very slight overhead
|
|
|
|
|
this adds.
|
|
|
|
|
|
[PATCH] Add debugging feature /proc/timer_stat
Add /proc/timer_stats support: debugging feature to profile timer expiration.
Both the starting site, process/PID and the expiration function is captured.
This allows the quick identification of timer event sources in a system.
Sample output:
# echo 1 > /proc/timer_stats
# cat /proc/timer_stats
Timer Stats Version: v0.1
Sample period: 4.010 s
24, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
11, 0 swapper sk_reset_timer (tcp_delack_timer)
6, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
17, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick)
2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
4, 2050 pcscd do_nanosleep (hrtimer_wakeup)
5, 4179 sshd sk_reset_timer (tcp_write_timer)
4, 2248 yum-updatesd schedule_timeout (process_timeout)
18, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick)
3, 0 swapper sk_reset_timer (tcp_delack_timer)
1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer)
2, 1 swapper e1000_up (e1000_watchdog)
1, 1 init schedule_timeout (process_timeout)
100 total events, 25.24 events/sec
[ cleanups and hrtimers support from Thomas Gleixner <tglx@linutronix.de> ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 09:28:13 +00:00
|
|
|
config TIMER_STATS
|
|
|
|
|
bool "Collect kernel timers statistics"
|
|
|
|
|
depends on DEBUG_KERNEL && PROC_FS
|
|
|
|
|
help
|
|
|
|
|
If you say Y here, additional code will be inserted into the
|
|
|
|
|
timer routines to collect statistics about kernel timers being
|
|
|
|
|
reprogrammed. The statistics can be read from /proc/timer_stats.
|
|
|
|
|
The statistics collection is started by writing 1 to /proc/timer_stats,
|
|
|
|
|
writing 0 stops it. This feature is useful to collect information
|
2007-06-01 07:47:16 +00:00
|
|
|
about timer usage patterns in kernel and userspace. This feature
|
|
|
|
|
is lightweight if enabled in the kernel config but not activated
|
|
|
|
|
(it defaults to deactivated on bootup and will only be activated
|
|
|
|
|
if some application like powertop activates it explicitly).
|
[PATCH] Add debugging feature /proc/timer_stat
Add /proc/timer_stats support: debugging feature to profile timer expiration.
Both the starting site, process/PID and the expiration function is captured.
This allows the quick identification of timer event sources in a system.
Sample output:
# echo 1 > /proc/timer_stats
# cat /proc/timer_stats
Timer Stats Version: v0.1
Sample period: 4.010 s
24, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
11, 0 swapper sk_reset_timer (tcp_delack_timer)
6, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
17, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick)
2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
4, 2050 pcscd do_nanosleep (hrtimer_wakeup)
5, 4179 sshd sk_reset_timer (tcp_write_timer)
4, 2248 yum-updatesd schedule_timeout (process_timeout)
18, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick)
3, 0 swapper sk_reset_timer (tcp_delack_timer)
1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer)
2, 1 swapper e1000_up (e1000_watchdog)
1, 1 init schedule_timeout (process_timeout)
100 total events, 25.24 events/sec
[ cleanups and hrtimers support from Thomas Gleixner <tglx@linutronix.de> ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 09:28:13 +00:00
|
|
|
|
2008-04-30 07:55:01 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-04-30 07:55:03 +00:00
|
|
|
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.
|
|
|
|
|
|
2009-11-15 16:09:48 +00:00
|
|
|
config DEBUG_OBJECTS_WORK
|
|
|
|
|
bool "Debug work objects"
|
|
|
|
|
depends on DEBUG_OBJECTS
|
|
|
|
|
help
|
|
|
|
|
If you say Y here, additional code will be inserted into the
|
|
|
|
|
work queue routines to track the life time of work objects and
|
|
|
|
|
validate the work operations.
|
|
|
|
|
|
2010-04-17 12:48:42 +00:00
|
|
|
config DEBUG_OBJECTS_RCU_HEAD
|
|
|
|
|
bool "Debug RCU callbacks objects"
|
|
|
|
|
depends on DEBUG_OBJECTS && PREEMPT
|
|
|
|
|
help
|
|
|
|
|
Enable this to turn on debugging of RCU list heads (call_rcu() usage).
|
|
|
|
|
|
2010-10-26 21:23:05 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-11-26 09:02:00 +00:00
|
|
|
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
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config DEBUG_SLAB
|
2006-03-25 11:07:22 +00:00
|
|
|
bool "Debug slab memory allocations"
|
2008-04-03 22:51:41 +00:00
|
|
|
depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
|
2005-04-16 22:20:36 +00:00
|
|
|
help
|
|
|
|
|
Say Y here to have the kernel do limited verification on memory
|
|
|
|
|
allocation as well as poisoning memory on free to catch use of freed
|
|
|
|
|
memory. This can make kmalloc/kfree-intensive workloads much slower.
|
|
|
|
|
|
2006-03-25 11:06:39 +00:00
|
|
|
config DEBUG_SLAB_LEAK
|
|
|
|
|
bool "Memory leak debugging"
|
|
|
|
|
depends on DEBUG_SLAB
|
|
|
|
|
|
2007-07-16 06:38:14 +00:00
|
|
|
config SLUB_DEBUG_ON
|
|
|
|
|
bool "SLUB debugging on by default"
|
2008-04-03 22:51:41 +00:00
|
|
|
depends on SLUB && SLUB_DEBUG && !KMEMCHECK
|
2007-07-16 06:38:14 +00:00
|
|
|
default n
|
|
|
|
|
help
|
|
|
|
|
Boot with debugging on by default. SLUB boots by default with
|
|
|
|
|
the runtime debug capabilities switched off. Enabling this is
|
|
|
|
|
equivalent to specifying the "slub_debug" parameter on boot.
|
|
|
|
|
There is no support for more fine grained debug control like
|
|
|
|
|
possible with slub_debug=xxx. SLUB debugging may be switched
|
|
|
|
|
off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
|
|
|
|
|
"slub_debug=-".
|
|
|
|
|
|
2008-02-08 01:47:41 +00:00
|
|
|
config SLUB_STATS
|
|
|
|
|
default n
|
|
|
|
|
bool "Enable SLUB performance statistics"
|
2010-10-05 18:57:26 +00:00
|
|
|
depends on SLUB && SYSFS
|
2008-02-08 01:47:41 +00:00
|
|
|
help
|
|
|
|
|
SLUB statistics are useful to debug SLUBs allocation behavior in
|
|
|
|
|
order find ways to optimize the allocator. This should never be
|
|
|
|
|
enabled for production use since keeping statistics slows down
|
|
|
|
|
the allocator by a few percentage points. The slabinfo command
|
|
|
|
|
supports the determination of the most active slabs to figure
|
|
|
|
|
out which slabs are relevant to a particular load.
|
|
|
|
|
Try running: slabinfo -DA
|
|
|
|
|
|
2009-06-11 12:24:13 +00:00
|
|
|
config DEBUG_KMEMLEAK
|
|
|
|
|
bool "Kernel memory leak detector"
|
2009-10-06 08:33:57 +00:00
|
|
|
depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
|
2010-10-14 18:54:47 +00:00
|
|
|
(X86 || ARM || PPC || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE)
|
2009-10-06 08:33:57 +00:00
|
|
|
|
2009-06-11 12:24:13 +00:00
|
|
|
select DEBUG_FS if SYSFS
|
|
|
|
|
select STACKTRACE if STACKTRACE_SUPPORT
|
|
|
|
|
select KALLSYMS
|
2009-11-06 23:33:45 +00:00
|
|
|
select CRC32
|
2009-06-11 12:24:13 +00:00
|
|
|
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.
|
|
|
|
|
|
2009-06-23 13:40:27 +00:00
|
|
|
Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
|
|
|
|
|
of finding leaks due to the slab objects poisoning.
|
|
|
|
|
|
2009-06-11 12:24:13 +00:00
|
|
|
In order to access the kmemleak file, debugfs needs to be
|
|
|
|
|
mounted (usually at /sys/kernel/debug).
|
|
|
|
|
|
2009-06-25 09:16:11 +00:00
|
|
|
config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
|
|
|
|
|
int "Maximum kmemleak early log entries"
|
|
|
|
|
depends on DEBUG_KMEMLEAK
|
2009-10-06 08:33:57 +00:00
|
|
|
range 200 40000
|
2009-06-25 09:16:11 +00:00
|
|
|
default 400
|
|
|
|
|
help
|
|
|
|
|
Kmemleak must track all the memory allocations to avoid
|
|
|
|
|
reporting false positives. Since memory may be allocated or
|
|
|
|
|
freed before kmemleak is initialised, an early log buffer is
|
|
|
|
|
used to store these actions. If kmemleak reports "early log
|
|
|
|
|
buffer exceeded", please increase this value.
|
|
|
|
|
|
2009-06-11 12:24:14 +00:00
|
|
|
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.
|
|
|
|
|
|
2010-07-19 10:54:17 +00:00
|
|
|
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.
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config DEBUG_PREEMPT
|
|
|
|
|
bool "Debug preemptible kernel"
|
2009-10-16 07:21:39 +00:00
|
|
|
depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
|
2005-04-16 22:20:36 +00:00
|
|
|
default y
|
|
|
|
|
help
|
|
|
|
|
If you say Y here then the kernel will use a debug variant of the
|
|
|
|
|
commonly used smp_processor_id() function and will print warnings
|
|
|
|
|
if kernel code uses it in a preemption-unsafe way. Also, the kernel
|
|
|
|
|
will detect preemption count underflows.
|
|
|
|
|
|
2006-06-27 09:54:55 +00:00
|
|
|
config DEBUG_RT_MUTEXES
|
|
|
|
|
bool "RT Mutex debugging, deadlock detection"
|
|
|
|
|
depends on DEBUG_KERNEL && RT_MUTEXES
|
|
|
|
|
help
|
|
|
|
|
This allows rt mutex semantics violations and rt mutex related
|
|
|
|
|
deadlocks (lockups) to be detected and reported automatically.
|
|
|
|
|
|
|
|
|
|
config DEBUG_PI_LIST
|
|
|
|
|
bool
|
|
|
|
|
default y
|
|
|
|
|
depends on DEBUG_RT_MUTEXES
|
|
|
|
|
|
2006-06-27 09:54:56 +00:00
|
|
|
config RT_MUTEX_TESTER
|
|
|
|
|
bool "Built-in scriptable tester for rt-mutexes"
|
2006-06-27 09:55:00 +00:00
|
|
|
depends on DEBUG_KERNEL && RT_MUTEXES
|
2006-06-27 09:54:56 +00:00
|
|
|
help
|
|
|
|
|
This option enables a rt-mutex tester.
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config DEBUG_SPINLOCK
|
2006-07-03 07:24:55 +00:00
|
|
|
bool "Spinlock and rw-lock debugging: basic checks"
|
2005-04-16 22:20:36 +00:00
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
Say Y here and build SMP to catch missing spinlock initialization
|
|
|
|
|
and certain other kinds of spinlock errors commonly made. This is
|
|
|
|
|
best used in conjunction with the NMI watchdog so that spinlock
|
|
|
|
|
deadlocks are also debuggable.
|
|
|
|
|
|
2006-07-03 07:24:55 +00:00
|
|
|
config DEBUG_MUTEXES
|
|
|
|
|
bool "Mutex debugging: basic checks"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
This feature allows mutex semantics violations to be detected and
|
|
|
|
|
reported.
|
|
|
|
|
|
|
|
|
|
config DEBUG_LOCK_ALLOC
|
|
|
|
|
bool "Lock debugging: detect incorrect freeing of live locks"
|
2006-07-14 07:24:32 +00:00
|
|
|
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
|
2006-07-03 07:24:55 +00:00
|
|
|
select DEBUG_SPINLOCK
|
|
|
|
|
select DEBUG_MUTEXES
|
|
|
|
|
select LOCKDEP
|
|
|
|
|
help
|
|
|
|
|
This feature will check whether any held lock (spinlock, rwlock,
|
|
|
|
|
mutex or rwsem) is incorrectly freed by the kernel, via any of the
|
|
|
|
|
memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
|
|
|
|
|
vfree(), etc.), whether a live lock is incorrectly reinitialized via
|
|
|
|
|
spin_lock_init()/mutex_init()/etc., or whether there is any lock
|
|
|
|
|
held during task exit.
|
|
|
|
|
|
|
|
|
|
config PROVE_LOCKING
|
|
|
|
|
bool "Lock debugging: prove locking correctness"
|
2006-07-14 07:24:32 +00:00
|
|
|
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
|
2006-07-03 07:24:55 +00:00
|
|
|
select LOCKDEP
|
|
|
|
|
select DEBUG_SPINLOCK
|
|
|
|
|
select DEBUG_MUTEXES
|
|
|
|
|
select DEBUG_LOCK_ALLOC
|
2010-08-31 20:35:20 +00:00
|
|
|
select TRACE_IRQFLAGS
|
2006-07-03 07:24:55 +00:00
|
|
|
default n
|
|
|
|
|
help
|
|
|
|
|
This feature enables the kernel to prove that all locking
|
|
|
|
|
that occurs in the kernel runtime is mathematically
|
|
|
|
|
correct: that under no circumstance could an arbitrary (and
|
|
|
|
|
not yet triggered) combination of observed locking
|
|
|
|
|
sequences (on an arbitrary number of CPUs, running an
|
|
|
|
|
arbitrary number of tasks and interrupt contexts) cause a
|
|
|
|
|
deadlock.
|
|
|
|
|
|
|
|
|
|
In short, this feature enables the kernel to report locking
|
|
|
|
|
related deadlocks before they actually occur.
|
|
|
|
|
|
|
|
|
|
The proof does not depend on how hard and complex a
|
|
|
|
|
deadlock scenario would be to trigger: how many
|
|
|
|
|
participant CPUs, tasks and irq-contexts would be needed
|
|
|
|
|
for it to trigger. The proof also does not depend on
|
|
|
|
|
timing: if a race and a resulting deadlock is possible
|
|
|
|
|
theoretically (no matter how unlikely the race scenario
|
|
|
|
|
is), it will be proven so and will immediately be
|
|
|
|
|
reported by the kernel (once the event is observed that
|
|
|
|
|
makes the deadlock theoretically possible).
|
|
|
|
|
|
|
|
|
|
If a deadlock is impossible (i.e. the locking rules, as
|
|
|
|
|
observed by the kernel, are mathematically correct), the
|
|
|
|
|
kernel reports nothing.
|
|
|
|
|
|
|
|
|
|
NOTE: this feature can also be enabled for rwlocks, mutexes
|
|
|
|
|
and rwsems - in which case all dependencies between these
|
|
|
|
|
different locking variants are observed and mapped too, and
|
|
|
|
|
the proof of observed correctness is also maintained for an
|
|
|
|
|
arbitrary combination of these separate locking variants.
|
|
|
|
|
|
|
|
|
|
For more details, see Documentation/lockdep-design.txt.
|
|
|
|
|
|
rcu: Introduce lockdep-based checking to RCU read-side primitives
Inspection is proving insufficient to catch all RCU misuses,
which is understandable given that rcu_dereference() might be
protected by any of four different flavors of RCU (RCU, RCU-bh,
RCU-sched, and SRCU), and might also/instead be protected by any
of a number of locking primitives. It is therefore time to
enlist the aid of lockdep.
This set of patches is inspired by earlier work by Peter
Zijlstra and Thomas Gleixner, and takes the following approach:
o Set up separate lockdep classes for RCU, RCU-bh, and RCU-sched.
o Set up separate lockdep classes for each instance of SRCU.
o Create primitives that check for being in an RCU read-side
critical section. These return exact answers if lockdep is
fully enabled, but if unsure, report being in an RCU read-side
critical section. (We want to avoid false positives!)
The primitives are:
For RCU: rcu_read_lock_held(void)
For RCU-bh: rcu_read_lock_bh_held(void)
For RCU-sched: rcu_read_lock_sched_held(void)
For SRCU: srcu_read_lock_held(struct srcu_struct *sp)
o Add rcu_dereference_check(), which takes a second argument
in which one places a boolean expression based on the above
primitives and/or lockdep_is_held().
o A new kernel configuration parameter, CONFIG_PROVE_RCU, enables
rcu_dereference_check(). This depends on CONFIG_PROVE_LOCKING,
and should be quite helpful during the transition period while
CONFIG_PROVE_RCU-unaware patches are in flight.
The existing rcu_dereference() primitive does no checking, but
upcoming patches will change that.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-23 01:04:45 +00:00
|
|
|
config PROVE_RCU
|
|
|
|
|
bool "RCU debugging: prove RCU correctness"
|
|
|
|
|
depends on PROVE_LOCKING
|
|
|
|
|
default n
|
|
|
|
|
help
|
|
|
|
|
This feature enables lockdep extensions that check for correct
|
|
|
|
|
use of RCU APIs. This is currently under development. Say Y
|
|
|
|
|
if you want to debug RCU usage or help work on the PROVE_RCU
|
|
|
|
|
feature.
|
|
|
|
|
|
|
|
|
|
Say N if you are unsure.
|
|
|
|
|
|
2010-04-20 08:23:07 +00:00
|
|
|
config PROVE_RCU_REPEATEDLY
|
|
|
|
|
bool "RCU debugging: don't disable PROVE_RCU on first splat"
|
|
|
|
|
depends on PROVE_RCU
|
|
|
|
|
default n
|
|
|
|
|
help
|
|
|
|
|
By itself, PROVE_RCU will disable checking upon issuing the
|
|
|
|
|
first warning (or "splat"). This feature prevents such
|
|
|
|
|
disabling, allowing multiple RCU-lockdep warnings to be printed
|
|
|
|
|
on a single reboot.
|
|
|
|
|
|
2010-09-16 06:30:48 +00:00
|
|
|
Say Y to allow multiple RCU-lockdep warnings per boot.
|
|
|
|
|
|
|
|
|
|
Say N if you are unsure.
|
|
|
|
|
|
2010-04-28 21:39:09 +00:00
|
|
|
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
|
|
|
|
|
|
2010-04-20 08:23:07 +00:00
|
|
|
Say N if you are unsure.
|
|
|
|
|
|
2006-07-03 07:24:55 +00:00
|
|
|
config LOCKDEP
|
|
|
|
|
bool
|
2006-07-14 07:24:32 +00:00
|
|
|
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
|
2006-07-03 07:24:55 +00:00
|
|
|
select STACKTRACE
|
2010-05-25 09:33:26 +00:00
|
|
|
select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE
|
2006-07-03 07:24:55 +00:00
|
|
|
select KALLSYMS
|
|
|
|
|
select KALLSYMS_ALL
|
|
|
|
|
|
2007-07-19 08:48:56 +00:00
|
|
|
config LOCK_STAT
|
2007-09-25 04:24:43 +00:00
|
|
|
bool "Lock usage statistics"
|
2007-07-19 08:48:56 +00:00
|
|
|
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
|
|
|
|
|
select LOCKDEP
|
|
|
|
|
select DEBUG_SPINLOCK
|
|
|
|
|
select DEBUG_MUTEXES
|
|
|
|
|
select DEBUG_LOCK_ALLOC
|
|
|
|
|
default n
|
|
|
|
|
help
|
|
|
|
|
This feature enables tracking lock contention points
|
|
|
|
|
|
2007-10-07 07:24:33 +00:00
|
|
|
For more details, see Documentation/lockstat.txt
|
|
|
|
|
|
2010-02-27 16:10:39 +00:00
|
|
|
This also enables lock events required by "perf lock",
|
|
|
|
|
subcommand of perf.
|
|
|
|
|
If you want to use "perf lock", you also need to turn on
|
|
|
|
|
CONFIG_EVENT_TRACING.
|
2010-02-04 07:08:15 +00:00
|
|
|
|
|
|
|
|
CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
|
2010-02-27 16:10:39 +00:00
|
|
|
(CONFIG_LOCKDEP defines "acquire" and "release" events.)
|
2010-02-04 07:08:15 +00:00
|
|
|
|
2006-07-03 07:24:55 +00:00
|
|
|
config DEBUG_LOCKDEP
|
|
|
|
|
bool "Lock dependency engine debugging"
|
2006-07-14 07:24:32 +00:00
|
|
|
depends on DEBUG_KERNEL && LOCKDEP
|
2006-07-03 07:24:55 +00:00
|
|
|
help
|
|
|
|
|
If you say Y here, the lock dependency engine will do
|
|
|
|
|
additional runtime checks to debug itself, at the price
|
|
|
|
|
of more runtime overhead.
|
|
|
|
|
|
|
|
|
|
config TRACE_IRQFLAGS
|
|
|
|
|
bool
|
2010-08-31 20:35:20 +00:00
|
|
|
help
|
|
|
|
|
Enables hooks to interrupt enabling and disabling for
|
|
|
|
|
either tracing or lock debugging.
|
2006-07-03 07:24:55 +00:00
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config DEBUG_SPINLOCK_SLEEP
|
2006-07-03 07:24:55 +00:00
|
|
|
bool "Spinlock debugging: sleep-inside-spinlock checking"
|
2005-04-16 22:20:36 +00:00
|
|
|
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.
|
|
|
|
|
|
2006-07-03 07:24:48 +00:00
|
|
|
config DEBUG_LOCKING_API_SELFTESTS
|
|
|
|
|
bool "Locking API boot-time self-tests"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
Say Y here if you want the kernel to run a short self-test during
|
|
|
|
|
bootup. The self-test checks whether common types of locking bugs
|
|
|
|
|
are detected by debugging mechanisms or not. (if you disable
|
|
|
|
|
lock debugging then those bugs wont be detected of course.)
|
|
|
|
|
The following locking APIs are covered: spinlocks, rwlocks,
|
|
|
|
|
mutexes and rwsems.
|
|
|
|
|
|
2006-07-03 07:24:38 +00:00
|
|
|
config STACKTRACE
|
|
|
|
|
bool
|
|
|
|
|
depends on STACKTRACE_SUPPORT
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config DEBUG_KOBJECT
|
|
|
|
|
bool "kobject debugging"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
If you say Y here, some extra kobject debugging messages will be sent
|
|
|
|
|
to the syslog.
|
|
|
|
|
|
|
|
|
|
config DEBUG_HIGHMEM
|
|
|
|
|
bool "Highmem debugging"
|
|
|
|
|
depends on DEBUG_KERNEL && HIGHMEM
|
|
|
|
|
help
|
|
|
|
|
This options enables addition error checking for high memory systems.
|
|
|
|
|
Disable for production systems.
|
|
|
|
|
|
|
|
|
|
config DEBUG_BUGVERBOSE
|
2011-01-20 22:44:16 +00:00
|
|
|
bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
|
2005-05-01 15:59:01 +00:00
|
|
|
depends on BUG
|
2008-02-08 12:19:31 +00:00
|
|
|
depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
|
|
|
|
|
FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
|
2009-12-15 02:00:25 +00:00
|
|
|
default y
|
2005-04-16 22:20:36 +00:00
|
|
|
help
|
|
|
|
|
Say Y here to make BUG() panics output the file name and line number
|
|
|
|
|
of the BUG call as well as the EIP and oops trace. This aids
|
|
|
|
|
debugging but costs about 70-100K of memory.
|
|
|
|
|
|
|
|
|
|
config DEBUG_INFO
|
|
|
|
|
bool "Compile the kernel with debug info"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
If you say Y here the resulting kernel image will include
|
|
|
|
|
debugging info resulting in a larger kernel image.
|
2007-03-27 21:21:33 +00:00
|
|
|
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.
|
2005-04-16 22:20:36 +00:00
|
|
|
Say Y here only if you plan to debug the kernel.
|
|
|
|
|
|
|
|
|
|
If unsure, say N.
|
|
|
|
|
|
2010-07-14 13:43:52 +00:00
|
|
|
config DEBUG_INFO_REDUCED
|
|
|
|
|
bool "Reduce debugging information"
|
|
|
|
|
depends on DEBUG_INFO
|
|
|
|
|
help
|
|
|
|
|
If you say Y here gcc is instructed to generate less debugging
|
|
|
|
|
information for structure types. This means that tools that
|
|
|
|
|
need full debugging information (like kgdb or systemtap) won't
|
|
|
|
|
be happy. But if you merely need debugging information to
|
|
|
|
|
resolve line numbers there is no loss. Advantage is that
|
|
|
|
|
build directory object sizes shrink dramatically over a full
|
|
|
|
|
DEBUG_INFO build and compile times are reduced too.
|
|
|
|
|
Only works with newer gcc versions.
|
|
|
|
|
|
2005-10-30 23:03:12 +00:00
|
|
|
config DEBUG_VM
|
|
|
|
|
bool "Debug VM"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
2006-01-06 08:10:58 +00:00
|
|
|
Enable this to turn on extended checks in the virtual-memory system
|
|
|
|
|
that may impact performance.
|
2005-10-30 23:03:12 +00:00
|
|
|
|
|
|
|
|
If unsure, say N.
|
|
|
|
|
|
2008-06-12 11:56:40 +00:00
|
|
|
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.
|
|
|
|
|
|
2009-01-08 12:04:47 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-02-15 22:38:01 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-07-24 04:26:49 +00:00
|
|
|
config DEBUG_MEMORY_INIT
|
2011-01-20 22:44:16 +00:00
|
|
|
bool "Debug memory initialisation" if EXPERT
|
|
|
|
|
default !EXPERT
|
2008-07-24 04:26:49 +00:00
|
|
|
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
|
|
|
|
|
|
2006-09-29 08:59:00 +00:00
|
|
|
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.
|
|
|
|
|
|
2010-10-26 21:23:05 +00:00
|
|
|
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.
|
|
|
|
|
|
2007-10-22 18:01:06 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-08-15 22:29:38 +00:00
|
|
|
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.
|
|
|
|
|
|
2009-09-02 08:13:40 +00:00
|
|
|
config DEBUG_CREDENTIALS
|
|
|
|
|
bool "Debug credential management"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
Enable this to turn on some debug checking for credential
|
|
|
|
|
management. The additional code keeps track of the number of
|
|
|
|
|
pointers from task_structs to any given cred struct, and checks to
|
|
|
|
|
see that this number never exceeds the usage count of the cred
|
|
|
|
|
struct.
|
|
|
|
|
|
|
|
|
|
Furthermore, if SELinux is enabled, this also checks that the
|
|
|
|
|
security pointer in the cred struct is never seen to be invalid.
|
|
|
|
|
|
|
|
|
|
If unsure, say N.
|
|
|
|
|
|
2009-01-16 18:23:35 +00:00
|
|
|
#
|
|
|
|
|
# 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
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
config FRAME_POINTER
|
|
|
|
|
bool "Compile the kernel with frame pointers"
|
2008-02-08 12:19:31 +00:00
|
|
|
depends on DEBUG_KERNEL && \
|
2011-01-22 21:35:38 +00:00
|
|
|
(CRIS || M68K || FRV || UML || \
|
2009-01-07 10:05:10 +00:00
|
|
|
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 gives very useful debugging information
|
|
|
|
|
in case of kernel bugs. (precise oopses/stacktraces/warnings)
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-10-16 08:23:46 +00:00
|
|
|
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.
|
|
|
|
|
|
2005-10-30 23:03:12 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-06-18 16:26:49 +00:00
|
|
|
Say Y here if you want RCU torture tests to be built into
|
|
|
|
|
the kernel.
|
2005-10-30 23:03:12 +00:00
|
|
|
Say M if you want the RCU torture tests to build as a module.
|
|
|
|
|
Say N if you are unsure.
|
2006-10-02 09:17:36 +00:00
|
|
|
|
2008-06-18 16:26:49 +00:00
|
|
|
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.
|
|
|
|
|
|
"Tree RCU": scalable classic RCU implementation
This patch fixes a long-standing performance bug in classic RCU that
results in massive internal-to-RCU lock contention on systems with
more than a few hundred CPUs. Although this patch creates a separate
flavor of RCU for ease of review and patch maintenance, it is intended
to replace classic RCU.
This patch still handles stress better than does mainline, so I am still
calling it ready for inclusion. This patch is against the -tip tree.
Nevertheless, experience on an actual 1000+ CPU machine would still be
most welcome.
Most of the changes noted below were found while creating an rcutiny
(which should permit ejecting the current rcuclassic) and while doing
detailed line-by-line documentation.
Updates from v9 (http://lkml.org/lkml/2008/12/2/334):
o Fixes from remainder of line-by-line code walkthrough,
including comment spelling, initialization, undesirable
narrowing due to type conversion, removing redundant memory
barriers, removing redundant local-variable initialization,
and removing redundant local variables.
I do not believe that any of these fixes address the CPU-hotplug
issues that Andi Kleen was seeing, but please do give it a whirl
in case the machine is smarter than I am.
A writeup from the walkthrough may be found at the following
URL, in case you are suffering from terminal insomnia or
masochism:
http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf
o Made rcutree tracing use seq_file, as suggested some time
ago by Lai Jiangshan.
o Added a .csv variant of the rcudata debugfs trace file, to allow
people having thousands of CPUs to drop the data into
a spreadsheet. Tested with oocalc and gnumeric. Updated
documentation to suit.
Updates from v8 (http://lkml.org/lkml/2008/11/15/139):
o Fix a theoretical race between grace-period initialization and
force_quiescent_state() that could occur if more than three
jiffies were required to carry out the grace-period
initialization. Which it might, if you had enough CPUs.
o Apply Ingo's printk-standardization patch.
o Substitute local variables for repeated accesses to global
variables.
o Fix comment misspellings and redundant (but harmless) increments
of ->n_rcu_pending (this latter after having explicitly added it).
o Apply checkpatch fixes.
Updates from v7 (http://lkml.org/lkml/2008/10/10/291):
o Fixed a number of problems noted by Gautham Shenoy, including
the cpu-stall-detection bug that he was having difficulty
convincing me was real. ;-)
o Changed cpu-stall detection to wait for ten seconds rather than
three in order to reduce false positive, as suggested by Ingo
Molnar.
o Produced a design document (http://lwn.net/Articles/305782/).
The act of writing this document uncovered a number of both
theoretical and "here and now" bugs as noted below.
o Fix dynticks_nesting accounting confusion, simplify WARN_ON()
condition, fix kerneldoc comments, and add memory barriers
in dynticks interface functions.
o Add more data to tracing.
o Remove unused "rcu_barrier" field from rcu_data structure.
o Count calls to rcu_pending() from scheduling-clock interrupt
to use as a surrogate timebase should jiffies stop counting.
o Fix a theoretical race between force_quiescent_state() and
grace-period initialization. Yes, initialization does have to
go on for some jiffies for this race to occur, but given enough
CPUs...
Updates from v6 (http://lkml.org/lkml/2008/9/23/448):
o Fix a number of checkpatch.pl complaints.
o Apply review comments from Ingo Molnar and Lai Jiangshan
on the stall-detection code.
o Fix several bugs in !CONFIG_SMP builds.
o Fix a misspelled config-parameter name so that RCU now announces
at boot time if stall detection is configured.
o Run tests on numerous combinations of configurations parameters,
which after the fixes above, now build and run correctly.
Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line):
o Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a
changeset some time ago, and finally got around to retesting
this option).
o Fix some tracing bugs in rcupreempt that caused incorrect
totals to be printed.
o I now test with a more brutal random-selection online/offline
script (attached). Probably more brutal than it needs to be
on the people reading it as well, but so it goes.
o A number of optimizations and usability improvements:
o Make rcu_pending() ignore the grace-period timeout when
there is no grace period in progress.
o Make force_quiescent_state() avoid going for a global
lock in the case where there is no grace period in
progress.
o Rearrange struct fields to improve struct layout.
o Make call_rcu() initiate a grace period if RCU was
idle, rather than waiting for the next scheduling
clock interrupt.
o Invoke rcu_irq_enter() and rcu_irq_exit() only when
idle, as suggested by Andi Kleen. I still don't
completely trust this change, and might back it out.
o Make CONFIG_RCU_TRACE be the single config variable
manipulated for all forms of RCU, instead of the prior
confusion.
o Document tracing files and formats for both rcupreempt
and rcutree.
Updates from v4 for those missing v5 given its bad subject line:
o Separated dynticks interface so that NMIs and irqs call separate
functions, greatly simplifying it. In particular, this code
no longer requires a proof of correctness. ;-)
o Separated dynticks state out into its own per-CPU structure,
avoiding the duplicated accounting.
o The case where a dynticks-idle CPU runs an irq handler that
invokes call_rcu() is now correctly handled, forcing that CPU
out of dynticks-idle mode.
o Review comments have been applied (thank you all!!!).
For but one example, fixed the dynticks-ordering issue that
Manfred pointed out, saving me much debugging. ;-)
o Adjusted rcuclassic and rcupreempt to handle dynticks changes.
Attached is an updated patch to Classic RCU that applies a hierarchy,
greatly reducing the contention on the top-level lock for large machines.
This passes 10-hour concurrent rcutorture and online-offline testing on
128-CPU ppc64 without dynticks enabled, and exposes some timekeeping
bugs in presence of dynticks (exciting working on a system where
"sleep 1" hangs until interrupted...), which were fixed in the
2.6.27 kernel. It is getting more reliable than mainline by some
measures, so the next version will be against -tip for inclusion.
See also Manfred Spraul's recent patches (or his earlier work from
2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2).
We will converge onto a common patch in the fullness of time, but are
currently exploring different regions of the design space. That said,
I have already gratefully stolen quite a few of Manfred's ideas.
This patch provides CONFIG_RCU_FANOUT, which controls the bushiness
of the RCU hierarchy. Defaults to 32 on 32-bit machines and 64 on
64-bit machines. If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT,
there is no hierarchy. By default, the RCU initialization code will
adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA
architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable
this balancing, allowing the hierarchy to be exactly aligned to the
underlying hardware. Up to two levels of hierarchy are permitted
(in addition to the root node), allowing up to 16,384 CPUs on 32-bit
systems and up to 262,144 CPUs on 64-bit systems. I just know that I
am going to regret saying this, but this seems more than sufficient
for the foreseeable future. (Some architectures might wish to set
CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs.
If this becomes a real problem, additional levels can be added, but I
doubt that it will make a significant difference on real hardware.)
In the common case, a given CPU will manipulate its private rcu_data
structure and the rcu_node structure that it shares with its immediate
neighbors. This can reduce both lock and memory contention by multiple
orders of magnitude, which should eliminate the need for the strange
manipulations that are reported to be required when running Linux on
very large systems.
Some shortcomings:
o More bugs will probably surface as a result of an ongoing
line-by-line code inspection.
Patches will be provided as required.
o There are probably hangs, rcutorture failures, &c. Seems
quite stable on a 128-CPU machine, but that is kind of small
compared to 4096 CPUs. However, seems to do better than
mainline.
Patches will be provided as required.
o The memory footprint of this version is several KB larger
than rcuclassic.
A separate UP-only rcutiny patch will be provided, which will
reduce the memory footprint significantly, even compared
to the old rcuclassic. One such patch passes light testing,
and has a memory footprint smaller even than rcuclassic.
Initial reaction from various embedded guys was "it is not
worth it", so am putting it aside.
Credits:
o Manfred Spraul for ideas, review comments, and bugs spotted,
as well as some good friendly competition. ;-)
o Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers,
Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton
for reviews and comments.
o Thomas Gleixner for much-needed help with some timer issues
(see patches below).
o Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos,
Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton
Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines
alive despite my heavy abuse^Wtesting.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 20:55:32 +00:00
|
|
|
config RCU_CPU_STALL_DETECTOR
|
|
|
|
|
bool "Check for stalled CPUs delaying RCU grace periods"
|
2009-08-22 20:56:53 +00:00
|
|
|
depends on TREE_RCU || TREE_PREEMPT_RCU
|
2009-12-02 20:10:16 +00:00
|
|
|
default y
|
"Tree RCU": scalable classic RCU implementation
This patch fixes a long-standing performance bug in classic RCU that
results in massive internal-to-RCU lock contention on systems with
more than a few hundred CPUs. Although this patch creates a separate
flavor of RCU for ease of review and patch maintenance, it is intended
to replace classic RCU.
This patch still handles stress better than does mainline, so I am still
calling it ready for inclusion. This patch is against the -tip tree.
Nevertheless, experience on an actual 1000+ CPU machine would still be
most welcome.
Most of the changes noted below were found while creating an rcutiny
(which should permit ejecting the current rcuclassic) and while doing
detailed line-by-line documentation.
Updates from v9 (http://lkml.org/lkml/2008/12/2/334):
o Fixes from remainder of line-by-line code walkthrough,
including comment spelling, initialization, undesirable
narrowing due to type conversion, removing redundant memory
barriers, removing redundant local-variable initialization,
and removing redundant local variables.
I do not believe that any of these fixes address the CPU-hotplug
issues that Andi Kleen was seeing, but please do give it a whirl
in case the machine is smarter than I am.
A writeup from the walkthrough may be found at the following
URL, in case you are suffering from terminal insomnia or
masochism:
http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf
o Made rcutree tracing use seq_file, as suggested some time
ago by Lai Jiangshan.
o Added a .csv variant of the rcudata debugfs trace file, to allow
people having thousands of CPUs to drop the data into
a spreadsheet. Tested with oocalc and gnumeric. Updated
documentation to suit.
Updates from v8 (http://lkml.org/lkml/2008/11/15/139):
o Fix a theoretical race between grace-period initialization and
force_quiescent_state() that could occur if more than three
jiffies were required to carry out the grace-period
initialization. Which it might, if you had enough CPUs.
o Apply Ingo's printk-standardization patch.
o Substitute local variables for repeated accesses to global
variables.
o Fix comment misspellings and redundant (but harmless) increments
of ->n_rcu_pending (this latter after having explicitly added it).
o Apply checkpatch fixes.
Updates from v7 (http://lkml.org/lkml/2008/10/10/291):
o Fixed a number of problems noted by Gautham Shenoy, including
the cpu-stall-detection bug that he was having difficulty
convincing me was real. ;-)
o Changed cpu-stall detection to wait for ten seconds rather than
three in order to reduce false positive, as suggested by Ingo
Molnar.
o Produced a design document (http://lwn.net/Articles/305782/).
The act of writing this document uncovered a number of both
theoretical and "here and now" bugs as noted below.
o Fix dynticks_nesting accounting confusion, simplify WARN_ON()
condition, fix kerneldoc comments, and add memory barriers
in dynticks interface functions.
o Add more data to tracing.
o Remove unused "rcu_barrier" field from rcu_data structure.
o Count calls to rcu_pending() from scheduling-clock interrupt
to use as a surrogate timebase should jiffies stop counting.
o Fix a theoretical race between force_quiescent_state() and
grace-period initialization. Yes, initialization does have to
go on for some jiffies for this race to occur, but given enough
CPUs...
Updates from v6 (http://lkml.org/lkml/2008/9/23/448):
o Fix a number of checkpatch.pl complaints.
o Apply review comments from Ingo Molnar and Lai Jiangshan
on the stall-detection code.
o Fix several bugs in !CONFIG_SMP builds.
o Fix a misspelled config-parameter name so that RCU now announces
at boot time if stall detection is configured.
o Run tests on numerous combinations of configurations parameters,
which after the fixes above, now build and run correctly.
Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line):
o Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a
changeset some time ago, and finally got around to retesting
this option).
o Fix some tracing bugs in rcupreempt that caused incorrect
totals to be printed.
o I now test with a more brutal random-selection online/offline
script (attached). Probably more brutal than it needs to be
on the people reading it as well, but so it goes.
o A number of optimizations and usability improvements:
o Make rcu_pending() ignore the grace-period timeout when
there is no grace period in progress.
o Make force_quiescent_state() avoid going for a global
lock in the case where there is no grace period in
progress.
o Rearrange struct fields to improve struct layout.
o Make call_rcu() initiate a grace period if RCU was
idle, rather than waiting for the next scheduling
clock interrupt.
o Invoke rcu_irq_enter() and rcu_irq_exit() only when
idle, as suggested by Andi Kleen. I still don't
completely trust this change, and might back it out.
o Make CONFIG_RCU_TRACE be the single config variable
manipulated for all forms of RCU, instead of the prior
confusion.
o Document tracing files and formats for both rcupreempt
and rcutree.
Updates from v4 for those missing v5 given its bad subject line:
o Separated dynticks interface so that NMIs and irqs call separate
functions, greatly simplifying it. In particular, this code
no longer requires a proof of correctness. ;-)
o Separated dynticks state out into its own per-CPU structure,
avoiding the duplicated accounting.
o The case where a dynticks-idle CPU runs an irq handler that
invokes call_rcu() is now correctly handled, forcing that CPU
out of dynticks-idle mode.
o Review comments have been applied (thank you all!!!).
For but one example, fixed the dynticks-ordering issue that
Manfred pointed out, saving me much debugging. ;-)
o Adjusted rcuclassic and rcupreempt to handle dynticks changes.
Attached is an updated patch to Classic RCU that applies a hierarchy,
greatly reducing the contention on the top-level lock for large machines.
This passes 10-hour concurrent rcutorture and online-offline testing on
128-CPU ppc64 without dynticks enabled, and exposes some timekeeping
bugs in presence of dynticks (exciting working on a system where
"sleep 1" hangs until interrupted...), which were fixed in the
2.6.27 kernel. It is getting more reliable than mainline by some
measures, so the next version will be against -tip for inclusion.
See also Manfred Spraul's recent patches (or his earlier work from
2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2).
We will converge onto a common patch in the fullness of time, but are
currently exploring different regions of the design space. That said,
I have already gratefully stolen quite a few of Manfred's ideas.
This patch provides CONFIG_RCU_FANOUT, which controls the bushiness
of the RCU hierarchy. Defaults to 32 on 32-bit machines and 64 on
64-bit machines. If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT,
there is no hierarchy. By default, the RCU initialization code will
adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA
architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable
this balancing, allowing the hierarchy to be exactly aligned to the
underlying hardware. Up to two levels of hierarchy are permitted
(in addition to the root node), allowing up to 16,384 CPUs on 32-bit
systems and up to 262,144 CPUs on 64-bit systems. I just know that I
am going to regret saying this, but this seems more than sufficient
for the foreseeable future. (Some architectures might wish to set
CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs.
If this becomes a real problem, additional levels can be added, but I
doubt that it will make a significant difference on real hardware.)
In the common case, a given CPU will manipulate its private rcu_data
structure and the rcu_node structure that it shares with its immediate
neighbors. This can reduce both lock and memory contention by multiple
orders of magnitude, which should eliminate the need for the strange
manipulations that are reported to be required when running Linux on
very large systems.
Some shortcomings:
o More bugs will probably surface as a result of an ongoing
line-by-line code inspection.
Patches will be provided as required.
o There are probably hangs, rcutorture failures, &c. Seems
quite stable on a 128-CPU machine, but that is kind of small
compared to 4096 CPUs. However, seems to do better than
mainline.
Patches will be provided as required.
o The memory footprint of this version is several KB larger
than rcuclassic.
A separate UP-only rcutiny patch will be provided, which will
reduce the memory footprint significantly, even compared
to the old rcuclassic. One such patch passes light testing,
and has a memory footprint smaller even than rcuclassic.
Initial reaction from various embedded guys was "it is not
worth it", so am putting it aside.
Credits:
o Manfred Spraul for ideas, review comments, and bugs spotted,
as well as some good friendly competition. ;-)
o Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers,
Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton
for reviews and comments.
o Thomas Gleixner for much-needed help with some timer issues
(see patches below).
o Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos,
Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton
Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines
alive despite my heavy abuse^Wtesting.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 20:55:32 +00:00
|
|
|
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.
|
2008-08-11 01:35:38 +00:00
|
|
|
|
2010-01-15 00:10:57 +00:00
|
|
|
Say N if you want to disable such checks.
|
2008-08-11 01:35:38 +00:00
|
|
|
|
2010-01-15 00:10:57 +00:00
|
|
|
Say Y if you are unsure.
|
2008-08-11 01:35:38 +00:00
|
|
|
|
2010-06-02 23:21:38 +00:00
|
|
|
config RCU_CPU_STALL_TIMEOUT
|
|
|
|
|
int "RCU CPU stall timeout in seconds"
|
|
|
|
|
depends on RCU_CPU_STALL_DETECTOR
|
|
|
|
|
range 3 300
|
|
|
|
|
default 60
|
|
|
|
|
help
|
|
|
|
|
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.
|
|
|
|
|
|
rcu: Allow RCU CPU stall warnings to be off at boot, but manually enablable
Currently, if RCU CPU stall warnings are enabled, they are enabled
immediately upon boot. They can be manually disabled via /sys (and
also re-enabled via /sys), and are automatically disabled upon panic.
However, some users need RCU CPU stalls to be disabled at boot time,
but to be enabled without rebuilding/rebooting. For example, someone
running a real-time application in production might not want the
additional latency of RCU CPU stall detection in normal operation, but
might need to enable it at any point for fault isolation purposes.
This commit therefore provides a new CONFIG_RCU_CPU_STALL_DETECTOR_RUNNABLE
kernel configuration parameter that maintains the current behavior
(enable at boot) by default, but allows a kernel to be configured
with RCU CPU stall detection built into the kernel, but disabled at
boot time.
Requested-by: Clark Williams <williams@redhat.com>
Requested-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-07-21 15:05:56 +00:00
|
|
|
config RCU_CPU_STALL_DETECTOR_RUNNABLE
|
|
|
|
|
bool "RCU CPU stall checking starts automatically at boot"
|
|
|
|
|
depends on RCU_CPU_STALL_DETECTOR
|
|
|
|
|
default y
|
|
|
|
|
help
|
|
|
|
|
If set, start checking for RCU CPU stalls immediately on
|
|
|
|
|
boot. Otherwise, RCU CPU stall checking must be manually
|
|
|
|
|
enabled.
|
|
|
|
|
|
|
|
|
|
Say Y if you are unsure.
|
|
|
|
|
|
|
|
|
|
Say N if you wish to suppress RCU CPU stall checking during boot.
|
|
|
|
|
|
2010-02-23 01:05:05 +00:00
|
|
|
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
|
2010-04-13 19:22:33 +00:00
|
|
|
default y
|
2010-02-23 01:05:05 +00:00
|
|
|
help
|
|
|
|
|
This option causes RCU to printk detailed per-task information
|
|
|
|
|
for any tasks that are stalling the current RCU grace period.
|
2008-08-11 01:35:38 +00:00
|
|
|
|
|
|
|
|
Say N if you are unsure.
|
|
|
|
|
|
2010-02-23 01:05:05 +00:00
|
|
|
Say Y if you want to enable such checks.
|
|
|
|
|
|
2008-01-30 12:32:53 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-01-30 12:33:08 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-06-27 16:04:48 +00:00
|
|
|
Note that if you want to also test saved backtraces, you will
|
|
|
|
|
have to enable STACKTRACE as well.
|
|
|
|
|
|
2008-01-30 12:33:08 +00:00
|
|
|
Say N if you are unsure.
|
|
|
|
|
|
2008-08-25 10:47:25 +00:00
|
|
|
config DEBUG_BLOCK_EXT_DEVT
|
|
|
|
|
bool "Force extended block device numbers and spread them"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
depends on BLOCK
|
2008-08-29 07:06:29 +00:00
|
|
|
default n
|
2008-08-25 10:47:25 +00:00
|
|
|
help
|
2008-10-13 08:46:01 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-08-25 10:47:25 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-09-01 11:44:35 +00:00
|
|
|
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.
|
|
|
|
|
|
2008-08-25 10:47:25 +00:00
|
|
|
Say N if you are unsure.
|
|
|
|
|
|
2009-06-24 06:13:50 +00:00
|
|
|
config DEBUG_FORCE_WEAK_PER_CPU
|
|
|
|
|
bool "Force weak per-cpu definitions"
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
s390 and alpha require percpu variables in modules to be
|
|
|
|
|
defined weak to work around addressing range issue which
|
|
|
|
|
puts the following two restrictions on percpu variable
|
|
|
|
|
definitions.
|
|
|
|
|
|
|
|
|
|
1. percpu symbols must be unique whether static or not
|
|
|
|
|
2. percpu variables can't be defined inside a function
|
|
|
|
|
|
|
|
|
|
To ensure that generic code follows the above rules, this
|
|
|
|
|
option forces all percpu variables to be defined as weak.
|
|
|
|
|
|
2006-10-02 09:17:36 +00:00
|
|
|
config LKDTM
|
|
|
|
|
tristate "Linux Kernel Dump Test Tool Module"
|
2010-03-05 21:42:49 +00:00
|
|
|
depends on DEBUG_FS
|
2008-02-23 23:23:26 +00:00
|
|
|
depends on BLOCK
|
2006-10-02 09:17:36 +00:00
|
|
|
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
|
2010-03-05 21:42:49 +00:00
|
|
|
Documentation/fault-injection/provoke-crashes.txt
|
2006-12-08 10:39:43 +00:00
|
|
|
|
2010-05-26 21:43:36 +00:00
|
|
|
config CPU_NOTIFIER_ERROR_INJECT
|
|
|
|
|
tristate "CPU notifier error injection module"
|
|
|
|
|
depends on HOTPLUG_CPU && DEBUG_KERNEL
|
|
|
|
|
help
|
|
|
|
|
This option provides a kernel module that can be used to test
|
|
|
|
|
the error handling of the cpu notifiers
|
|
|
|
|
|
|
|
|
|
To compile this code as a module, choose M here: the module will
|
|
|
|
|
be called cpu-notifier-error-inject.
|
|
|
|
|
|
|
|
|
|
If unsure, say N.
|
|
|
|
|
|
2006-12-08 10:39:43 +00:00
|
|
|
config FAULT_INJECTION
|
2006-12-08 10:39:49 +00:00
|
|
|
bool "Fault-injection framework"
|
|
|
|
|
depends on DEBUG_KERNEL
|
2006-12-08 10:39:48 +00:00
|
|
|
help
|
|
|
|
|
Provide fault-injection framework.
|
|
|
|
|
For more details, see Documentation/fault-injection/.
|
2006-12-08 10:39:43 +00:00
|
|
|
|
2006-12-08 10:39:44 +00:00
|
|
|
config FAILSLAB
|
2006-12-08 10:39:49 +00:00
|
|
|
bool "Fault-injection capability for kmalloc"
|
|
|
|
|
depends on FAULT_INJECTION
|
2008-12-23 10:37:01 +00:00
|
|
|
depends on SLAB || SLUB
|
2006-12-08 10:39:44 +00:00
|
|
|
help
|
2006-12-08 10:39:49 +00:00
|
|
|
Provide fault-injection capability for kmalloc.
|
2006-12-08 10:39:44 +00:00
|
|
|
|
2006-12-08 10:39:45 +00:00
|
|
|
config FAIL_PAGE_ALLOC
|
|
|
|
|
bool "Fault-injection capabilitiy for alloc_pages()"
|
2006-12-08 10:39:49 +00:00
|
|
|
depends on FAULT_INJECTION
|
2006-12-08 10:39:45 +00:00
|
|
|
help
|
2006-12-08 10:39:49 +00:00
|
|
|
Provide fault-injection capability for alloc_pages().
|
2006-12-08 10:39:45 +00:00
|
|
|
|
2006-12-08 10:39:46 +00:00
|
|
|
config FAIL_MAKE_REQUEST
|
2006-12-12 19:16:36 +00:00
|
|
|
bool "Fault-injection capability for disk IO"
|
2008-09-14 12:56:33 +00:00
|
|
|
depends on FAULT_INJECTION && BLOCK
|
2006-12-08 10:39:46 +00:00
|
|
|
help
|
2006-12-08 10:39:49 +00:00
|
|
|
Provide fault-injection capability for disk IO.
|
2006-12-08 10:39:46 +00:00
|
|
|
|
2008-09-14 12:56:33 +00:00
|
|
|
config FAIL_IO_TIMEOUT
|
2010-07-21 07:05:53 +00:00
|
|
|
bool "Fault-injection capability for faking disk interrupts"
|
2008-09-14 12:56:33 +00:00
|
|
|
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.
|
|
|
|
|
|
2006-12-08 10:39:43 +00:00
|
|
|
config FAULT_INJECTION_DEBUG_FS
|
|
|
|
|
bool "Debugfs entries for fault-injection capabilities"
|
2006-12-08 10:39:49 +00:00
|
|
|
depends on FAULT_INJECTION && SYSFS && DEBUG_FS
|
2006-12-08 10:39:43 +00:00
|
|
|
help
|
2006-12-08 10:39:49 +00:00
|
|
|
Enable configuration of fault-injection capabilities via debugfs.
|
2007-02-20 21:57:56 +00:00
|
|
|
|
|
|
|
|
config FAULT_INJECTION_STACKTRACE_FILTER
|
|
|
|
|
bool "stacktrace filter for fault-injection capabilities"
|
|
|
|
|
depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
|
2007-05-12 17:36:53 +00:00
|
|
|
depends on !X86_64
|
2007-02-20 21:57:56 +00:00
|
|
|
select STACKTRACE
|
2010-05-25 09:33:26 +00:00
|
|
|
select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE
|
2007-02-20 21:57:56 +00:00
|
|
|
help
|
|
|
|
|
Provide stacktrace filter for fault-injection capabilities
|
2007-10-19 06:41:07 +00:00
|
|
|
|
2008-01-25 20:08:34 +00:00
|
|
|
config LATENCYTOP
|
|
|
|
|
bool "Latency measuring infrastructure"
|
2010-08-12 19:31:21 +00:00
|
|
|
depends on HAVE_LATENCYTOP_SUPPORT
|
|
|
|
|
depends on DEBUG_KERNEL
|
|
|
|
|
depends on STACKTRACE_SUPPORT
|
|
|
|
|
depends on PROC_FS
|
2010-05-25 09:33:26 +00:00
|
|
|
select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE
|
2008-01-25 20:08:34 +00:00
|
|
|
select KALLSYMS
|
|
|
|
|
select KALLSYMS_ALL
|
|
|
|
|
select STACKTRACE
|
|
|
|
|
select SCHEDSTATS
|
|
|
|
|
select SCHED_DEBUG
|
|
|
|
|
help
|
|
|
|
|
Enable this option if you want to use the LatencyTOP tool
|
|
|
|
|
to find out which userspace is blocking on what kernel operations.
|
|
|
|
|
|
2008-08-16 05:53:05 +00:00
|
|
|
config SYSCTL_SYSCALL_CHECK
|
|
|
|
|
bool "Sysctl checks"
|
2009-04-03 09:22:26 +00:00
|
|
|
depends on SYSCTL
|
2008-08-16 05:53:05 +00:00
|
|
|
---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.
|
|
|
|
|
|
2009-03-31 22:23:17 +00:00
|
|
|
source mm/Kconfig.debug
|
2008-05-12 19:20:42 +00:00
|
|
|
source kernel/trace/Kconfig
|
|
|
|
|
|
x86: early boot debugging via FireWire (ohci1394_dma=early)
This patch adds a new configuration option, which adds support for a new
early_param which gets checked in arch/x86/kernel/setup_{32,64}.c:setup_arch()
to decide wether OHCI-1394 FireWire controllers should be initialized and
enabled for physical DMA access to allow remote debugging of early problems
like issues ACPI or other subsystems which are executed very early.
If the config option is not enabled, no code is changed, and if the boot
paramenter is not given, no new code is executed, and independent of that,
all new code is freed after boot, so the config option can be even enabled
in standard, non-debug kernels.
With specialized tools, it is then possible to get debugging information
from machines which have no serial ports (notebooks) such as the printk
buffer contents, or any data which can be referenced from global pointers,
if it is stored below the 4GB limit and even memory dumps of of the physical
RAM region below the 4GB limit can be taken without any cooperation from the
CPU of the host, so the machine can be crashed early, it does not matter.
In the extreme, even kernel debuggers can be accessed in this way. I wrote
a small kgdb module and an accompanying gdb stub for FireWire which allows
to gdb to talk to kgdb using remote remory reads and writes over FireWire.
An version of the gdb stub fore FireWire is able to read all global data
from a system which is running a a normal kernel without any kernel debugger,
without any interruption or support of the system's CPU. That way, e.g. the
task struct and so on can be read and even manipulated when the physical DMA
access is granted.
A HOWTO is included in this patch, in Documentation/debugging-via-ohci1394.txt
and I've put a copy online at
ftp://ftp.suse.de/private/bk/firewire/docs/debugging-via-ohci1394.txt
It also has links to all the tools which are available to make use of it
another copy of it is online at:
ftp://ftp.suse.de/private/bk/firewire/kernel/ohci1394_dma_early-v2.diff
Signed-Off-By: Bernhard Kaindl <bk@suse.de>
Tested-By: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:34:11 +00:00
|
|
|
config PROVIDE_OHCI1394_DMA_INIT
|
2008-02-28 19:54:43 +00:00
|
|
|
bool "Remote debugging over FireWire early on boot"
|
x86: early boot debugging via FireWire (ohci1394_dma=early)
This patch adds a new configuration option, which adds support for a new
early_param which gets checked in arch/x86/kernel/setup_{32,64}.c:setup_arch()
to decide wether OHCI-1394 FireWire controllers should be initialized and
enabled for physical DMA access to allow remote debugging of early problems
like issues ACPI or other subsystems which are executed very early.
If the config option is not enabled, no code is changed, and if the boot
paramenter is not given, no new code is executed, and independent of that,
all new code is freed after boot, so the config option can be even enabled
in standard, non-debug kernels.
With specialized tools, it is then possible to get debugging information
from machines which have no serial ports (notebooks) such as the printk
buffer contents, or any data which can be referenced from global pointers,
if it is stored below the 4GB limit and even memory dumps of of the physical
RAM region below the 4GB limit can be taken without any cooperation from the
CPU of the host, so the machine can be crashed early, it does not matter.
In the extreme, even kernel debuggers can be accessed in this way. I wrote
a small kgdb module and an accompanying gdb stub for FireWire which allows
to gdb to talk to kgdb using remote remory reads and writes over FireWire.
An version of the gdb stub fore FireWire is able to read all global data
from a system which is running a a normal kernel without any kernel debugger,
without any interruption or support of the system's CPU. That way, e.g. the
task struct and so on can be read and even manipulated when the physical DMA
access is granted.
A HOWTO is included in this patch, in Documentation/debugging-via-ohci1394.txt
and I've put a copy online at
ftp://ftp.suse.de/private/bk/firewire/docs/debugging-via-ohci1394.txt
It also has links to all the tools which are available to make use of it
another copy of it is online at:
ftp://ftp.suse.de/private/bk/firewire/kernel/ohci1394_dma_early-v2.diff
Signed-Off-By: Bernhard Kaindl <bk@suse.de>
Tested-By: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:34:11 +00:00
|
|
|
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.
|
2008-01-25 20:08:34 +00:00
|
|
|
|
2008-02-28 19:54:43 +00:00
|
|
|
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.
|
|
|
|
|
|
2009-02-20 23:38:47 +00:00
|
|
|
config BUILD_DOCSRC
|
docsrc: build Documentation/ sources
Currently source files in the Documentation/ sub-dir can easily bit-rot
since they are not generally buildable, either because they are hidden in
text files or because there are no Makefile rules for them. This needs to
be fixed so that the source files remain usable and good examples of code
instead of bad examples.
Add the ability to build source files that are in the Documentation/ dir.
Add to Kconfig as "BUILD_DOCSRC" config symbol.
Use "CONFIG_BUILD_DOCSRC=1 make ..." to build objects from the
Documentation/ sources. Or enable BUILD_DOCSRC in the *config system.
However, this symbol depends on HEADERS_CHECK since the header files need
to be installed (for userspace builds).
Built (using cross-tools) for x86-64, i386, alpha, ia64, sparc32,
sparc64, powerpc, sh, m68k, & mips.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-12 22:09:06 +00:00
|
|
|
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.
|
|
|
|
|
|
2009-02-05 16:51:38 +00:00
|
|
|
config DYNAMIC_DEBUG
|
2009-02-05 16:53:15 +00:00
|
|
|
bool "Enable dynamic printk() support"
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
default n
|
|
|
|
|
depends on PRINTK
|
2009-02-05 16:53:15 +00:00
|
|
|
depends on DEBUG_FS
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
help
|
|
|
|
|
|
|
|
|
|
Compiles debug level messages into the kernel, which would not
|
|
|
|
|
otherwise be available at runtime. These messages can then be
|
2009-02-05 16:53:15 +00:00
|
|
|
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%.
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
|
|
|
|
Usage:
|
|
|
|
|
|
2010-05-24 21:33:21 +00:00
|
|
|
Dynamic debugging is controlled via the 'dynamic_debug/control' file,
|
2009-02-05 16:53:15 +00:00
|
|
|
which is contained in the 'debugfs' filesystem. Thus, the debugfs
|
|
|
|
|
filesystem must first be mounted before making use of this feature.
|
2010-05-24 21:33:21 +00:00
|
|
|
We refer the control file as: <debugfs>/dynamic_debug/control. This
|
2009-02-05 16:53:15 +00:00
|
|
|
file contains a list of the debug statements that can be enabled. The
|
|
|
|
|
format for each line of the file is:
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
2009-02-05 16:53:15 +00:00
|
|
|
filename:lineno [module]function flags format
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
2009-02-05 16:53:15 +00:00
|
|
|
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
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
|
|
|
|
From a live system:
|
|
|
|
|
|
2010-05-24 21:33:21 +00:00
|
|
|
nullarbor:~ # cat <debugfs>/dynamic_debug/control
|
2009-02-05 16:53:15 +00:00
|
|
|
# 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"
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
2009-02-05 16:53:15 +00:00
|
|
|
Example usage:
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
2009-02-05 16:53:15 +00:00
|
|
|
// enable the message at line 1603 of file svcsock.c
|
|
|
|
|
nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
|
2010-05-24 21:33:21 +00:00
|
|
|
<debugfs>/dynamic_debug/control
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
2009-02-05 16:53:15 +00:00
|
|
|
// enable all the messages in file svcsock.c
|
|
|
|
|
nullarbor:~ # echo -n 'file svcsock.c +p' >
|
2010-05-24 21:33:21 +00:00
|
|
|
<debugfs>/dynamic_debug/control
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
|
|
2009-02-05 16:53:15 +00:00
|
|
|
// enable all the messages in the NFS server module
|
|
|
|
|
nullarbor:~ # echo -n 'module nfsd +p' >
|
2010-05-24 21:33:21 +00:00
|
|
|
<debugfs>/dynamic_debug/control
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
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2009-02-05 16:53:15 +00:00
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// enable all 12 messages in the function svc_process()
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nullarbor:~ # echo -n 'func svc_process +p' >
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2010-05-24 21:33:21 +00:00
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<debugfs>/dynamic_debug/control
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
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|
2009-02-05 16:53:15 +00:00
|
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// disable all 12 messages in the function svc_process()
|
|
|
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nullarbor:~ # echo -n 'func svc_process -p' >
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2010-05-24 21:33:21 +00:00
|
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<debugfs>/dynamic_debug/control
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
|
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|
2009-02-05 16:53:15 +00:00
|
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See Documentation/dynamic-debug-howto.txt for additional information.
|
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
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2009-01-09 11:14:24 +00:00
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config DMA_API_DEBUG
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bool "Enable debugging of DMA-API usage"
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depends on HAVE_DMA_API_DEBUG
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help
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Enable this option to debug the use of the DMA API by device drivers.
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With this option you will be able to detect common bugs in device
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drivers like double-freeing of DMA mappings or freeing mappings that
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were never allocated.
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This option causes a performance degredation. Use only if you want
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to debug device drivers. If unsure, say N.
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driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages.
I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
control of debugging statements on a per-module basis in one /proc file,
currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
is not set, debugging statements can still be enabled as before, often by
defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
can be dynamically enabled/disabled on a per-module basis.
Future plans include extending this functionality to subsystems, that define
their own debug levels and flags.
Usage:
Dynamic debugging is controlled by the debugfs file,
<debugfs>/dynamic_printk/modules. This file contains a list of the modules that
can be enabled. The format of the file is as follows:
<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
For example:
snd_hda_intel enabled=0
fixup enabled=1
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.
[gkh: minor cleanups and tweaks to make the build work quietly]
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-12 20:46:19 +00:00
|
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|
2010-02-24 09:54:24 +00:00
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config ATOMIC64_SELFTEST
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bool "Perform an atomic64_t self-test at boot"
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help
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Enable this option to test the atomic64_t functions at boot.
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If unsure, say N.
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2010-10-07 22:25:04 +00:00
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config ASYNC_RAID6_TEST
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tristate "Self test for hardware accelerated raid6 recovery"
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depends on ASYNC_RAID6_RECOV
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select ASYNC_MEMCPY
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---help---
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This is a one-shot self test that permutes through the
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recovery of all the possible two disk failure scenarios for a
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N-disk array. Recovery is performed with the asynchronous
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raid6 recovery routines, and will optionally use an offload
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engine if one is available.
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If unsure, say N.
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2007-10-19 06:41:07 +00:00
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source "samples/Kconfig"
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2008-04-17 18:05:37 +00:00
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source "lib/Kconfig.kgdb"
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2009-02-26 19:38:56 +00:00
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source "lib/Kconfig.kmemcheck"
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