09 May, 2007
2 commits
-
Several people have observed that perhaps LOG_BUF_SHIFT should be in a more
obvious place than under DEBUG_KERNEL. Under some circumstances (such as the
PARISC architecture), DEBUG_KERNEL can increase kernel size, which is an
undesirable trade off for something as trivial as increasing the kernel log
buffer size.Instead, move LOG_BUF_SHIFT into "General Setup", so that people are more
likely to be able to change it such a circumstance that the default buffer
size is insufficient.Signed-off-by: Alistair John Strachan
Acked-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the Kconfig selection of semaphore debugging from the ALPHA and FRV
Kconfig files, and centralize it in lib/Kconfig.debug.There doesn't seem to be much point in letting individual architectures
independently define the same Kconfig option when it can just as easily be
put in a single Kconfig file and made dependent on a subset of
architectures. that way, at least the option shows up in the same relative
location in the menu each time.Signed-off-by: Robert P. J. Day
Cc: David Howells
Cc: Ivan Kokshaysky
Cc: Richard Henderson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2007
1 commit
-
This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix! Tinyboards.The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc. (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000. Since then ADI has put this core into its Blackfin
processor family of devices. The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set. It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdfThe Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibcThis patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu
Signed-off-by: Mariusz Kozlowski
Signed-off-by: Aubrey Li
Signed-off-by: Jie Zhang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 May, 2007
1 commit
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The following patch adds some extra clarification to the CONFIG_DEBUG_INFO
Kconfig help text. The current text is mostly a recursive definition and
doesn't really say much of anything. When I first read this I thought it
was going to enable extra verbosity in debug messages or something, but it
is only enabling the "gcc -g" compile option in the Makefile.Signed-off-by: Andreas Dilger
Signed-off-by: Sam Ravnborg
27 Apr, 2007
1 commit
-
Stacktrace support on MIPS doesn't use frame pointers. Since this option
considerably increases the size of the kernel code, force lockdep to not
use it.Signed-off-by: Franck Bui-Huu
Signed-off-by: Ralf Baechle
21 Feb, 2007
1 commit
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There is no prompt for CONFIG_STACKTRACE, so FAULT_INJECTION cannot be
selected without LOCKDEP enabled. (found by Paolo 'Blaisorblade'
Giarrusso)In order to fix such broken Kconfig dependency, this patch splits up the
stacktrace filter support for fault injection by new Kconfig option, which
enables to use fault injection on the architecture which doesn't have
general stacktrace support.Cc: "Paolo 'Blaisorblade' Giarrusso"
Signed-off-by: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Feb, 2007
1 commit
-
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 ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Cc: john stultz
Cc: Roman Zippel
Cc: Andi Kleen
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Feb, 2007
1 commit
-
Drivers registering IRQ handlers with SA_SHIRQ really ought to be able to
handle an interrupt happening before request_irq() returns. They also
ought to be able to handle an interrupt happening during the start of their
call to free_irq(). Let's test that hypothesis....[bunk@stusta.de: Kconfig fixes]
Signed-off-by: David Woodhouse
Cc: Arjan van de Ven
Signed-off-by: Jesper Juhl
Signed-off-by: Ingo Molnar
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Feb, 2007
1 commit
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Remove the few references to the obsolete kernel config option
DEBUG_RWSEMS.Signed-off-by: Robert P. J. Day
Cc: Ingo Molnar
Cc: David Howells
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Dec, 2006
1 commit
-
It has caused more problems than it ever really solved, and is
apparently not getting cleaned up and fixed. We can put it back when
it's stable and isn't likely to make warning or bug events worse.In the meantime, enable frame pointers for more readable stack traces.
Signed-off-by: Linus Torvalds
13 Dec, 2006
1 commit
-
Signed-off-by: Dave Jones
Signed-off-by: Adrian Bunk
11 Dec, 2006
1 commit
-
Refactor Kconfig content to maximize nesting of menus by menuconfig and
xconfig.Tested by simultaneously running `make xconfig` with and without
patch, and comparing displays.Signed-off-by: Don Mullis
Signed-off-by: Randy Dunlap
Cc: Sam Ravnborg
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Dec, 2006
9 commits
-
`select' doesn't work very well. With alpha `make allmodconfig' we end up
with CONFIG_STACKTRACE enabled, so we end up with undefined save_stacktrace()
at link time.Cc: Akinobu Mita
Cc: Don Mullis
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Fix some spelling and grammatical errors
- Make the Kconfig menu more conventional. First you select
fault-injection, then under that you select particular clients of it.Cc: Akinobu Mita
Cc: Don Mullis
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch provides stacktrace filtering feature.
The stacktrace filter allows failing only for the caller you are
interested in.For example someone may want to inject kmalloc() failures into
only e100 module. they want to inject not only direct kmalloc() call,
but also indirect allocation, too.- e100_poll --> netif_receive_skb --> packet_rcv_spkt --> skb_clone
--> kmem_cache_allocThis patch enables to detect function calls like this by stacktrace
and inject failures. The script Documentaion/fault-injection/failmodule.sh
helps it.The range of text section of loaded e100 is expected to be
[/sys/module/e100/sections/.text, /sys/module/e100/sections/.exit.text)So failmodule.sh stores these values into /debug/failslab/address-start
and /debug/failslab/address-end. The maximum stacktrace depth is specified
by /debug/failslab/stacktrace-depth.Please see the example that demonstrates how to inject slab allocation
failures only for a specific module
in Documentation/fault-injection/fault-injection.txt[dwm@meer.net: reject failure if any caller lies within specified range]
Signed-off-by: Akinobu Mita
Signed-off-by: Don Mullis
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch provides fault-injection capability for disk IO.
Boot option:
fail_make_request=,,,
-- specifies the interval of failures.
-- specifies how often it should fail in percent.
-- specifies the size of free space where disk IO can be issued
safely in bytes.-- specifies how many times failures may happen at most.
Debugfs:
/debug/fail_make_request/interval
/debug/fail_make_request/probability
/debug/fail_make_request/specifies
/debug/fail_make_request/timesExample:
fail_make_request=10,100,0,-1
echo 1 > /sys/blocks/hda/hda1/make-it-failgeneric_make_request() on /dev/hda1 fails once per 10 times.
Cc: Jens Axboe
Signed-off-by: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch provides fault-injection capability for alloc_pages()
Boot option:
fail_page_alloc=,,,
-- specifies the interval of failures.
-- specifies how often it should fail in percent.
-- specifies the size of free space where memory can be
allocated safely in pages.-- specifies how many times failures may happen at most.
Debugfs:
/debug/fail_page_alloc/interval
/debug/fail_page_alloc/probability
/debug/fail_page_alloc/specifies
/debug/fail_page_alloc/times
/debug/fail_page_alloc/ignore-gfp-highmem
/debug/fail_page_alloc/ignore-gfp-waitExample:
fail_page_alloc=10,100,0,-1
The page allocation (alloc_pages(), ...) fails once per 10 times.
Signed-off-by: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch provides fault-injection capability for kmalloc.
Boot option:
failslab=,,,
-- specifies the interval of failures.
-- specifies how often it should fail in percent.
-- specifies the size of free space where memory can be
allocated safely in bytes.-- specifies how many times failures may happen at most.
Debugfs:
/debug/failslab/interval
/debug/failslab/probability
/debug/failslab/specifies
/debug/failslab/times
/debug/failslab/ignore-gfp-highmem
/debug/failslab/ignore-gfp-waitExample:
failslab=10,100,0,-1
slab allocation (kmalloc(), kmem_cache_alloc(),..) fails once per 10 times.
Cc: Pekka Enberg
Signed-off-by: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch provides base functions implement to fault-injection
capabilities.- The function should_fail() is taken from failmalloc-1.0
(http://www.nongnu.org/failmalloc/)[akpm@osdl.org: cleanups, comments, add __init]
Cc:
Signed-off-by: Akinobu Mita
Signed-off-by: Don Mullis
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This makes i386 use the generic BUG machinery. There are no functional
changes from the old i386 implementation.The main advantage in using the generic BUG machinery for i386 is that the
inlined overhead of BUG is just the ud2a instruction; the file+line(+function)
information are no longer inlined into the instruction stream. This reduces
cache pollution, and makes disassembly work properly.Signed-off-by: Jeremy Fitzhardinge
Cc: Andi Kleen
Cc: Hugh Dickens
Cc: Michael Ellerman
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Rusty Russell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch adds common handling for kernel BUGs, for use by architectures as
they wish. The code is derived from arch/powerpc.The advantages of having common BUG handling are:
- consistent BUG reporting across architectures
- shared implementation of out-of-line file/line data
- implement CONFIG_DEBUG_BUGVERBOSE consistentlyThis means that in inline impact of BUG is just the illegal instruction
itself, which is an improvement for i386 and x86-64.A BUG is represented in the instruction stream as an illegal instruction,
which has file/line information associated with it. This extra information is
stored in the __bug_table section in the ELF file.When the kernel gets an illegal instruction, it first confirms it might
possibly be from a BUG (ie, in kernel mode, the right illegal instruction).
It then calls report_bug(). This searches __bug_table for a matching
instruction pointer, and if found, prints the corresponding file/line
information. If report_bug() determines that it wasn't a BUG which caused the
trap, it returns BUG_TRAP_TYPE_NONE.Some architectures (powerpc) implement WARN using the same mechanism; if the
illegal instruction was the result of a WARN, then report_bug(Q) returns
CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG.lib/bug.c keeps a list of loaded modules which can be searched for __bug_table
entries. The architecture must call
module_bug_finalize()/module_bug_cleanup() from its corresponding
module_finalize/cleanup functions.Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount.
At the very least, filename and line information will not be recorded for each
but, but architectures may decide to store no extra information per BUG at
all.Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so
architectures will generally have to include an infinite loop (or similar) in
the BUG code, so that gcc knows execution won't continue beyond that point.
gcc does have a __builtin_trap() operator which may be useful to achieve the
same effect, unfortunately it cannot be used to actually implement the BUG
itself, because there's no way to get the instruction's address for use in
generating the __bug_table entry.[randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors]
[bunk@stusta.de: include/linux/bug.h must always #include
Cc: Andi Kleen
Cc: Hugh Dickens
Cc: Michael Ellerman
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Rusty Russell
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
1 commit
-
Make PRINTK_TIME depend on PRINTK. Only display/offer it if PRINTK is
enabled.Signed-off-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Oct, 2006
1 commit
-
According to Daniel Jacobowitz, UNWIND_INFO is not useful on ARM, and
in fact doesn't even compile.This patch disables the option for ARM.
Signed-off-by: Kevin Hilman
Signed-off-by: Russell King
13 Oct, 2006
1 commit
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The lack of asm-um/Kbuild is deliberate.
Signed-off-by: Al Viro
Signed-off-by: Linus Torvalds
12 Oct, 2006
2 commits
-
In order to encourage people to notice when they break the exported
headers, add a config option which automatically runs the sanity checks
when building vmlinux. That way, those who use allyesconfig will notice
failures.Signed-off-by: David Woodhouse
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We got several false bug reports because of enabled
CONFIG_DETECT_SOFTLOCKUP. Disable soft lockup detection on s390, since it
doesn't work on a virtualized architecture.Cc: Martin Schwidefsky
Signed-off-by: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Oct, 2006
1 commit
-
A simple module to test Linux Kernel Dump mechanism. This module uses
jprobes to install/activate pre-defined crash points. At different crash
points, various types of crashing scenarios are created like a BUG(),
panic(), exception, recursive loop and stack overflow. The user can
activate a crash point with specific type by providing parameters at the
time of module insertion. Please see the file header for usage
information. The module is based on the Linux Kernel Dump Test Tool by
Fernando .This module could be merged with mainline. Jprobes is used here so that the
context in which crash point is hit, could be maintained. This implements
all the crash points as done by LKDTT except the one in the middle of
tasklet_action().Signed-off-by: Ankita Garg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Sep, 2006
1 commit
-
Signed-off-by: Dave Jones
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Sep, 2006
4 commits
-
Add SH to the list of platforms interested in Verbose BUG().
Signed-off-by: Paul Mundt
-
We had our own version, which serves no purpose. Simply
hook SH in to the generic one.Signed-off-by: Paul Mundt
-
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (225 commits)
[PATCH] Don't set calgary iommu as default y
[PATCH] i386/x86-64: New Intel feature flags
[PATCH] x86: Add a cumulative thermal throttle event counter.
[PATCH] i386: Make the jiffies compares use the 64bit safe macros.
[PATCH] x86: Refactor thermal throttle processing
[PATCH] Add 64bit jiffies compares (for use with get_jiffies_64)
[PATCH] Fix unwinder warning in traps.c
[PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
[PATCH] x86: Move direct PCI scanning functions out of line
[PATCH] i386/x86-64: Make all early PCI scans dependent on CONFIG_PCI
[PATCH] Don't leak NT bit into next task
[PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder
[PATCH] Fix some broken white space in ia32_signal.c
[PATCH] Initialize argument registers for 32bit signal handlers.
[PATCH] Remove all traces of signal number conversion
[PATCH] Don't synchronize time reading on single core AMD systems
[PATCH] Remove outdated comment in x86-64 mmconfig code
[PATCH] Use string instructions for Core2 copy/clear
[PATCH] x86: - restore i8259A eoi status on resume
[PATCH] i386: Split multi-line printk in oops output.
... -
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (47 commits)
Driver core: Don't call put methods while holding a spinlock
Driver core: Remove unneeded routines from driver core
Driver core: Fix potential deadlock in driver core
PCI: enable driver multi-threaded probe
Driver Core: add ability for drivers to do a threaded probe
sysfs: add proper sysfs_init() prototype
drivers/base: check errors
drivers/base: Platform notify needs to occur before drivers attach to the device
v4l-dev2: handle __must_check
add CONFIG_ENABLE_MUST_CHECK
add __must_check to device management code
Driver core: fixed add_bind_files() definition
Driver core: fix comments in drivers/base/power/resume.c
sysfs_remove_bin_file: no return value, dump_stack on error
kobject: must_check fixes
Driver core: add ability for devices to create and remove bin files
Class: add support for class interfaces for devices
Driver core: create devices/virtual/ tree
Driver core: add device_rename function
Driver core: add ability for classes to handle devices properly
...
26 Sep, 2006
3 commits
-
This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
CPU and the AT32STK1000 development board.AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
cost-sensitive embedded applications, with particular emphasis on low power
consumption and high code density. The AVR32 architecture is not binary
compatible with earlier 8-bit AVR architectures.The AVR32 architecture, including the instruction set, is described by the
AVR32 Architecture Manual, available fromhttp://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf
The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture. It
features a 7-stage pipeline, 16KB instruction and data caches and a full
Memory Management Unit. It also comes with a large set of integrated
peripherals, many of which are shared with the AT91 ARM-based controllers from
Atmel.Full data sheet is available from
http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf
while the CPU core implementation including caches and MMU is documented by
the AVR32 AP Technical Reference, available fromhttp://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf
Information about the AT32STK1000 development board can be found at
http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918
including a BSP CD image with an earlier version of this patch, development
tools (binaries and source/patches) and a root filesystem image suitable for
booting from SD card.Alternatively, there's a preliminary "getting started" guide available at
http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
to the sources and patches you will need in order to set up a cross-compiling
environment for avr32-linux.This patch, as well as the other patches included with the BSP and the
toolchain patches, is actively supported by Atmel Corporation.[dmccr@us.ibm.com: Fix more pxx_page macro locations]
[bunk@stusta.de: fix `make defconfig']
Signed-off-by: Haavard Skinnemoen
Signed-off-by: Adrian Bunk
Signed-off-by: Dave McCracken
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that stacktrace supports dwarf2 don't force frame pointers for lockdep anymore
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen -
Those 1500 warnings can be a bit of a pain. Add a config option to shut them
up.Signed-off-by: Andrew Morton
Signed-off-by: Greg Kroah-Hartman
15 Jul, 2006
1 commit
-
The lockdep options should depend on DEBUG_KERNEL since:
- they are kernel debugging options and
- they do otherwise break the DEBUG_KERNEL menu structureSigned-off-by: Adrian Bunk
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2006
4 commits
-
Offer the following lock validation options:
CONFIG_PROVE_LOCKING
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do 'make oldconfig' and accept all the defaults for new config options -
reboot into the kernel and if everything goes well it should boot up fine and
you should have /proc/lockdep and /proc/lockdep_stats files.Typically if the lock validator finds some problem it will print out
voluminous debug output that begins with "BUG: ..." and which syslog output
can be used by kernel developers to figure out the precise locking scenario.What does the lock validator do? It "observes" and maps all locking rules as
they occur dynamically (as triggered by the kernel's natural use of spinlocks,
rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a
new locking scenario, it validates this new rule against the existing set of
rules. If this new rule is consistent with the existing set of rules then the
new rule is added transparently and the kernel continues as normal. If the
new rule could create a deadlock scenario then this condition is printed out.When determining validity of locking, all possible "deadlock scenarios" are
considered: assuming arbitrary number of CPUs, arbitrary irq context and task
context constellations, running arbitrary combinations of all the existing
locking scenarios. In a typical system this means millions of separate
scenarios. This is why we call it a "locking correctness" validator - for all
rules that are observed the lock validator proves it with mathematical
certainty that a deadlock could not occur (assuming that the lock validator
implementation itself is correct and its internal data structures are not
corrupted by some other kernel subsystem). [see more details and conditionals
of this statement in include/linux/lockdep.h and
Documentation/lockdep-design.txt]Furthermore, this "all possible scenarios" property of the validator also
enables the finding of complex, highly unlikely multi-CPU multi-context races
via single single-context rules, increasing the likelyhood of finding bugs
drastically. In practical terms: the lock validator already found a bug in
the upstream kernel that could only occur on systems with 3 or more CPUs, and
which needed 3 very unlikely code sequences to occur at once on the 3 CPUs.
That bug was found and reported on a single-CPU system (!). So in essence a
race will be found "piecemail-wise", triggering all the necessary components
for the race, without having to reproduce the race scenario itself! In its
short existence the lock validator found and reported many bugs before they
actually caused a real deadlock.To further increase the efficiency of the validator, the mapping is not per
"lock instance", but per "lock-class". For example, all struct inode objects
in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached,
then there are 10,000 lock objects. But ->inotify_mutex is a single "lock
type", and all locking activities that occur against ->inotify_mutex are
"unified" into this single lock-class. The advantage of the lock-class
approach is that all historical ->inotify_mutex uses are mapped into a single
(and as narrow as possible) set of locking rules - regardless of how many
different tasks or inode structures it took to build this set of rules. The
set of rules persist during the lifetime of the kernel.To see the rough magnitude of checking that the lock validator does, here's a
portion of /proc/lockdep_stats, fresh after bootup:lock-classes: 694 [max: 2048]
direct dependencies: 1598 [max: 8192]
indirect dependencies: 17896
all direct dependencies: 16206
dependency chains: 1910 [max: 8192]
in-hardirq chains: 17
in-softirq chains: 105
in-process chains: 1065
stack-trace entries: 38761 [max: 131072]
combined max dependencies: 2033928
hardirq-safe locks: 24
hardirq-unsafe locks: 176
softirq-safe locks: 53
softirq-unsafe locks: 137
irq-safe locks: 59
irq-unsafe locks: 176The lock validator has observed 1598 actual single-thread locking patterns,
and has validated all possible 2033928 distinct locking scenarios.More details about the design of the lock validator can be found in
Documentation/lockdep-design.txt, which can also found at:http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt
[bunk@stusta.de: cleanups]
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce DEBUG_LOCKING_API_SELFTESTS, which uses the generic lock debugging
code's silent-failure feature to run a matrix of testcases. There are 210
testcases currently:+-----------------------
| Locking API testsuite:
+------------------------------+------+------+------+------+------+------+
| spin |wlock |rlock |mutex | wsem | rsem |
-------------------------------+------+------+------+------+------+------+
A-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-B-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-B-C-C-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-C-A-B-C deadlock: ok | ok | ok | ok | ok | ok |
A-B-B-C-C-D-D-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-C-D-B-D-D-A deadlock: ok | ok | ok | ok | ok | ok |
A-B-C-D-B-C-D-A deadlock: ok | ok | ok | ok | ok | ok |
double unlock: ok | ok | ok | ok | ok | ok |
bad unlock order: ok | ok | ok | ok | ok | ok |
--------------------------------------+------+------+------+------+------+
recursive read-lock: | ok | | ok |
--------------------------------------+------+------+------+------+------+
non-nested unlock: ok | ok | ok | ok |
--------------------------------------+------+------+------+
hard-irqs-on + irq-safe-A/12: ok | ok | ok |
soft-irqs-on + irq-safe-A/12: ok | ok | ok |
hard-irqs-on + irq-safe-A/21: ok | ok | ok |
soft-irqs-on + irq-safe-A/21: ok | ok | ok |
sirq-safe-A => hirqs-on/12: ok | ok | ok |
sirq-safe-A => hirqs-on/21: ok | ok | ok |
hard-safe-A + irqs-on/12: ok | ok | ok |
soft-safe-A + irqs-on/12: ok | ok | ok |
hard-safe-A + irqs-on/21: ok | ok | ok |
soft-safe-A + irqs-on/21: ok | ok | ok |
hard-safe-A + unsafe-B #1/123: ok | ok | ok |
soft-safe-A + unsafe-B #1/123: ok | ok | ok |
hard-safe-A + unsafe-B #1/132: ok | ok | ok |
soft-safe-A + unsafe-B #1/132: ok | ok | ok |
hard-safe-A + unsafe-B #1/213: ok | ok | ok |
soft-safe-A + unsafe-B #1/213: ok | ok | ok |
hard-safe-A + unsafe-B #1/231: ok | ok | ok |
soft-safe-A + unsafe-B #1/231: ok | ok | ok |
hard-safe-A + unsafe-B #1/312: ok | ok | ok |
soft-safe-A + unsafe-B #1/312: ok | ok | ok |
hard-safe-A + unsafe-B #1/321: ok | ok | ok |
soft-safe-A + unsafe-B #1/321: ok | ok | ok |
hard-safe-A + unsafe-B #2/123: ok | ok | ok |
soft-safe-A + unsafe-B #2/123: ok | ok | ok |
hard-safe-A + unsafe-B #2/132: ok | ok | ok |
soft-safe-A + unsafe-B #2/132: ok | ok | ok |
hard-safe-A + unsafe-B #2/213: ok | ok | ok |
soft-safe-A + unsafe-B #2/213: ok | ok | ok |
hard-safe-A + unsafe-B #2/231: ok | ok | ok |
soft-safe-A + unsafe-B #2/231: ok | ok | ok |
hard-safe-A + unsafe-B #2/312: ok | ok | ok |
soft-safe-A + unsafe-B #2/312: ok | ok | ok |
hard-safe-A + unsafe-B #2/321: ok | ok | ok |
soft-safe-A + unsafe-B #2/321: ok | ok | ok |
hard-irq lock-inversion/123: ok | ok | ok |
soft-irq lock-inversion/123: ok | ok | ok |
hard-irq lock-inversion/132: ok | ok | ok |
soft-irq lock-inversion/132: ok | ok | ok |
hard-irq lock-inversion/213: ok | ok | ok |
soft-irq lock-inversion/213: ok | ok | ok |
hard-irq lock-inversion/231: ok | ok | ok |
soft-irq lock-inversion/231: ok | ok | ok |
hard-irq lock-inversion/312: ok | ok | ok |
soft-irq lock-inversion/312: ok | ok | ok |
hard-irq lock-inversion/321: ok | ok | ok |
soft-irq lock-inversion/321: ok | ok | ok |
hard-irq read-recursion/123: ok |
soft-irq read-recursion/123: ok |
hard-irq read-recursion/132: ok |
soft-irq read-recursion/132: ok |
hard-irq read-recursion/213: ok |
soft-irq read-recursion/213: ok |
hard-irq read-recursion/231: ok |
soft-irq read-recursion/231: ok |
hard-irq read-recursion/312: ok |
soft-irq read-recursion/312: ok |
hard-irq read-recursion/321: ok |
soft-irq read-recursion/321: ok |
--------------------------------+-----+----------------
Good, all 210 testcases passed! |
--------------------------------+Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
CONFIG_FRAME_POINTER support for s390.
Signed-off-by: Heiko Carstens
Acked-by: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds