We can see an ever repeating problem pattern with objects of any kind in the
kernel:
1) freeing of active objects
2) reinitialization of active objects
Both problems can be hard to debug because the crash happens at a point where
we have no chance to decode the root cause anymore. One problem spot are
kernel timers, where the detection of the problem often happens in interrupt
context and usually causes the machine to panic.
While working on a timer related bug report I had to hack specialized code
into the timer subsystem to get a reasonable hint for the root cause. This
debug hack was fine for temporary use, but far from a mergeable solution due
to the intrusiveness into the timer code.
The code further lacked the ability to detect and report the root cause
instantly and keep the system operational.
Keeping the system operational is important to get hold of the debug
information without special debugging aids like serial consoles and special
knowledge of the bug reporter.
The problems described above are not restricted to timers, but timers tend to
expose it usually in a full system crash. Other objects are less explosive,
but the symptoms caused by such mistakes can be even harder to debug.
Instead of creating specialized debugging code for the timer subsystem a
generic infrastructure is created which allows developers to verify their code
and provides an easy to enable debug facility for users in case of trouble.
The debugobjects core code keeps track of operations on static and dynamic
objects by inserting them into a hashed list and sanity checking them on
object operations and provides additional checks whenever kernel memory is
freed.
The tracked object operations are:
- initializing an object
- adding an object to a subsystem list
- deleting an object from a subsystem list
Each operation is sanity checked before the operation is executed and the
subsystem specific code can provide a fixup function which allows to prevent
the damage of the operation. When the sanity check triggers a warning message
and a stack trace is printed.
The list of operations can be extended if the need arises. For now it's
limited to the requirements of the first user (timers).
The core code enqueues the objects into hash buckets. The hash index is
generated from the address of the object to simplify the lookup for the check
on kfree/vfree. Each bucket has it's own spinlock to avoid contention on a
global lock.
The debug code can be compiled in without being active. The runtime overhead
is minimal and could be optimized by asm alternatives. A kernel command line
option enables the debugging code.
Thanks to Ingo Molnar for review, suggestions and cleanup patches.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add "max_ratio" to /sys/class/bdi. This indicates the maximum percentage of
the global dirty threshold allocated to this bdi.
[mszeredi@suse.cz]
- fix parsing in max_ratio_store().
- export bdi_set_max_ratio() to modules
- limit bdi_dirty with bdi->max_ratio
- document new sysfs attribute
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object.
This allows us to see and set the various BDI specific variables.
In particular this properly exposes the read-ahead window for all relevant
users and /sys/block/<block>/queue/read_ahead_kb should be deprecated.
With patient help from Kay Sievers and Greg KH
[mszeredi@suse.cz]
- split off NFS and FUSE changes into separate patches
- document new sysfs attributes under Documentation/ABI
- do bdi_class_init as a core_initcall, otherwise the "default" BDI
won't be initialized
- remove bdi_init_fmt macro, it's not used very much
[akpm@linux-foundation.org: fix ia64 warning]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg KH <greg@kroah.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[RAPIDIO] Change RapidIO doorbell source and target ID field to 16-bit
[RAPIDIO] Add RapidIO connection info print out and re-training for broken connections
[RAPIDIO] Add serial RapidIO controller support, which includes MPC8548, MPC8641
[RAPIDIO] Add RapidIO node probing into MPC86xx_HPCN board id table
[RAPIDIO] Add RapidIO node into MPC8641HPCN dts file
[RAPIDIO] Auto-probe the RapidIO system size
[RAPIDIO] Add OF-tree support to RapidIO controller driver
[RAPIDIO] Add RapidIO multi mport support
[RAPIDIO] Move include/asm-ppc/rio.h to asm-powerpc
[RAPIDIO] Add RapidIO option to kernel configuration
[RAPIDIO] Change RIO function mpc85xx_ to fsl_
[POWERPC] Provide walk_memory_resource() for powerpc
[POWERPC] Update lmb data structures for hotplug memory add/remove
[POWERPC] Hotplug memory remove notifications for powerpc
[POWERPC] windfarm: Add PowerMac 12,1 support
[POWERPC] Fix building of pmac32 when CONFIG_NVRAM=m
[POWERPC] Add IRQSTACKS support on ppc32
[POWERPC] Use __always_inline for xchg* and cmpxchg*
[POWERPC] Add fast little-endian switch system call
The mapsize optimizations which were moved from x86 to the generic
code in commit 64970b68d2 increased the
binary size on non x86 architectures.
Looking into the real effects of the "optimizations" it turned out
that they are not used in find_next_bit() and find_next_zero_bit().
The ones in find_first_bit() and find_first_zero_bit() are used in a
couple of places but none of them is a real hot path.
Remove the "optimizations" all together and call the library functions
unconditionally.
Boot-tested on x86 and compile tested on every cross compiler I have.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid a possible kmem_cache_create() failure by creating idr_layer_cache
unconditionary at boot time rather than creating it on-demand when idr_init()
is called the first time.
This change also enables us to eliminate the check every time idr_init() is
called.
[akpm@linux-foundation.org: rename init_id_cache() to idr_init_cache()]
[akpm@linux-foundation.org: fix alpha build]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change all ia64 machvecs to use the new dma_*map*_attrs() interfaces.
Implement the old dma_*map_*() interfaces in terms of the corresponding new
interfaces. For ia64/sn, make use of one dma attribute,
DMA_ATTR_WRITE_BARRIER. Introduce swiotlb_*map*_attrs() functions.
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some
serious complaining of kernel, we need repeat the warnings, so here I isolate
the ratelimit part of printk.c to a standalone file.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
iommu_is_span_boundary in lib/iommu-helper.c was exported for PARISC IOMMUs
(commit 3715863aa1). SWIOTLB can use it instead
of the homegrown function.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a pointlessly braced block of code in there. Remove the braces and
save a tabstop.
Cc: Andi Kleen <ak@suse.de>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Almost all implementations of pci_iomap() in the kernel, including the generic
lib/iomap.c one, copies the content of a struct resource into unsigned long's
which will break on 32 bits platforms with 64 bits resources.
This fixes all definitions of pci_iomap() to use resource_size_t. I also
"fixed" the 64bits arch for consistency.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide walk_memory_resource() for 64-bit powerpc. PowerPC maintains
logical memory region mapping in the lmb.memory structure. Walk
through these structures and do the callbacks for the contiguous
chunks.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The powerpc kernel maintains information about logical memory blocks
in the lmb.memory structure, which is initialized and updated at boot
time, but not when memory is added or removed while the kernel is
running.
This adds a hotplug memory notifier which updates lmb.memory when
memory is added or removed. This information is useful for eHEA
driver to find out the memory layout and holes.
NOTE: No special locking is needed for lmb_add() and lmb_remove().
Calls to these are serialized by caller. (pSeries_reconfig_chain).
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The following adds two more bitmap operators, bitmap_onto() and bitmap_fold(),
with the usual cpumask and nodemask wrappers.
The bitmap_onto() operator computes one bitmap relative to another. If the
n-th bit in the origin mask is set, then the m-th bit of the destination mask
will be set, where m is the position of the n-th set bit in the relative mask.
The bitmap_fold() operator folds a bitmap into a second that has bit m set iff
the input bitmap has some bit n set, where m == n mod sz, for the specified sz
value.
There are two substantive changes between this patch and its
predecessor bitmap_relative:
1) Renamed bitmap_relative() to be bitmap_onto().
2) Added bitmap_fold().
The essential motivation for bitmap_onto() is to provide a mechanism for
converting a cpuset-relative CPU or Node mask to an absolute mask. Cpuset
relative masks are written as if the current task were in a cpuset whose CPUs
or Nodes were just the consecutive ones numbered 0..N-1, for some N. The
bitmap_onto() operator is provided in anticipation of adding support for the
first such cpuset relative mask, by the mbind() and set_mempolicy() system
calls, using a planned flag of MPOL_F_RELATIVE_NODES. These bitmap operators
(and their nodemask wrappers, in particular) will be used in code that
converts the user specified cpuset relative memory policy to a specific system
node numbered policy, given the current mems_allowed of the tasks cpuset.
Such cpuset relative mempolicies will address two deficiencies
of the existing interface between cpusets and mempolicies:
1) A task cannot at present reliably establish a cpuset
relative mempolicy because there is an essential race
condition, in that the tasks cpuset may be changed in
between the time the task can query its cpuset placement,
and the time the task can issue the applicable mbind or
set_memplicy system call.
2) A task cannot at present establish what cpuset relative
mempolicy it would like to have, if it is in a smaller
cpuset than it might have mempolicy preferences for,
because the existing interface only allows specifying
mempolicies for nodes currently allowed by the cpuset.
Cpuset relative mempolicies are useful for tasks that don't distinguish
particularly between one CPU or Node and another, but only between how many of
each are allowed, and the proper placement of threads and memory pages on the
various CPUs and Nodes available.
The motivation for the added bitmap_fold() can be seen in the following
example.
Let's say an application has specified some mempolicies that presume 16 memory
nodes, including say a mempolicy that specified MPOL_F_RELATIVE_NODES (cpuset
relative) nodes 12-15. Then lets say that application is crammed into a
cpuset that only has 8 memory nodes, 0-7. If one just uses bitmap_onto(),
this mempolicy, mapped to that cpuset, would ignore the requested relative
nodes above 7, leaving it empty of nodes. That's not good; better to fold the
higher nodes down, so that some nodes are included in the resulting mapped
mempolicy. In this case, the mempolicy nodes 12-15 are taken modulo 8 (the
weight of the mems_allowed of the confining cpuset), resulting in a mempolicy
specifying nodes 4-7.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: <kosaki.motohiro@jp.fujitsu.com>
Cc: <ray-lk@madrabbit.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Migrate flags must be set on slab creation as agreed upon when the antifrag
logic was reviewed. Otherwise some slabs of a slabcache will end up in the
unmovable and others in the reclaimable section depending on which flag was
active when a new slab page was allocated.
This likely slid in somehow when antifrag was merged. Remove it.
The buffer_heads are always allocated with __GFP_RECLAIMABLE because the
SLAB_RECLAIM_ACCOUNT option is set. The set_migrateflags() never had any
effect there.
Radix tree allocations are not directly reclaimable but they are allocated
with __GFP_RECLAIMABLE set on each allocation. We now set
SLAB_RECLAIM_ACCOUNT on radix tree slab creation making sure that radix
tree slabs are consistently placed in the reclaimable section. Radix tree
slabs will also be accounted as such.
There is then no user left of set_migratepages. So remove it.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce GENERIC_FIND_FIRST_BIT and GENERIC_FIND_NEXT_BIT in
lib/Kconfig, defaulting to off. An arch that wants to use the
generic implementation now only has to use a select statement
to include them.
I added an always-y option (X86_CPU) to arch/x86/Kconfig.cpu
and used that to select the generic search functions. This
way ARCH=um SUBARCH=i386 automatically picks up the change
too, and arch/um/Kconfig.i386 can therefore be simplified a
bit. ARCH=um SUBARCH=x86_64 does things differently, but
still compiles fine. It seems that a "def_bool y" always
wins over a "def_bool n"?
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Generic versions of __find_first_bit and __find_first_zero_bit
are introduced as simplified versions of __find_next_bit and
__find_next_zero_bit. Their compilation and use are guarded by
a new config variable GENERIC_FIND_FIRST_BIT.
The generic versions of find_first_bit and find_first_zero_bit
are implemented in terms of the newly introduced __find_first_bit
and __find_first_zero_bit.
This patch does not remove the i386-specific implementation,
but it does switch i386 to use the generic functions by setting
GENERIC_FIND_FIRST_BIT=y for X86_32.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This moves an optimization for searching constant-sized small
bitmaps form x86_64-specific to generic code.
On an i386 defconfig (the x86#testing one), the size of vmlinux hardly
changes with this applied. I have observed only four places where this
optimization avoids a call into find_next_bit:
In the functions return_unused_surplus_pages, alloc_fresh_huge_page,
and adjust_pool_surplus, this patch avoids a call for a 1-bit bitmap.
In __next_cpu a call is avoided for a 32-bit bitmap. That's it.
On x86_64, 52 locations are optimized with a minimal increase in
code size:
Current #testing defconfig:
146 x bsf, 27 x find_next_*bit
text data bss dec hex filename
5392637 846592 724424 6963653 6a41c5 vmlinux
After removing the x86_64 specific optimization for find_next_*bit:
94 x bsf, 79 x find_next_*bit
text data bss dec hex filename
5392358 846592 724424 6963374 6a40ae vmlinux
After this patch (making the optimization generic):
146 x bsf, 27 x find_next_*bit
text data bss dec hex filename
5392396 846592 724424 6963412 6a40d4 vmlinux
[ tglx@linutronix.de: build fixes ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The versions with inline assembly are in fact slower on the machines I
tested them on (in userspace) (Athlon XP 2800+, p4-like Xeon 2.8GHz, AMD
Opteron 270). The i386-version needed a fix similar to 06024f21 to avoid
crashing the benchmark.
Benchmark using: gcc -fomit-frame-pointer -Os. For each bitmap size
1...512, for each possible bitmap with one bit set, for each possible
offset: find the position of the first bit starting at offset. If you
follow ;). Times include setup of the bitmap and checking of the
results.
Athlon Xeon Opteron 32/64bit
x86-specific: 0m3.692s 0m2.820s 0m3.196s / 0m2.480s
generic: 0m2.622s 0m1.662s 0m2.100s / 0m1.572s
If the bitmap size is not a multiple of BITS_PER_LONG, and no set
(cleared) bit is found, find_next_bit (find_next_zero_bit) returns a
value outside of the range [0, size]. The generic version always returns
exactly size. The generic version also uses unsigned long everywhere,
while the x86 versions use a mishmash of int, unsigned (int), long and
unsigned long.
Using the generic version does give a slightly bigger kernel, though.
defconfig: text data bss dec hex filename
x86-specific: 4738555 481232 626688 5846475 5935cb vmlinux (32 bit)
generic: 4738621 481232 626688 5846541 59360d vmlinux (32 bit)
x86-specific: 5392395 846568 724424 6963387 6a40bb vmlinux (64 bit)
generic: 5392458 846568 724424 6963450 6a40fa vmlinux (64 bit)
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add option to enable -Wframe-larger-than= on gcc 4.4
gcc mainline (upcoming 4.4) added a new -Wframe-larger-than=...
option to warn at build time about too large stack frames. Add a config
option to enable this warning, since this very useful for the kernel.
I choose (somewhat arbitarily) 2048 as default warning threshold for 64bit
and 1024 as default for 32bit architectures. With some research and
fixing all the code for smaller values these defaults should be probably
lowered.
With the default allyesconfigs have some new warnings, but I think
that is all code that should be just fixed.
At some point (when gcc 4.4 is released and widely used) this should
obsolete make checkstack
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Changeset d9024df02f ("[LMB] Restructure
allocation loops to avoid unsigned underflow") removed the alignment
of the 'size' argument to call lmb_add_region() done by __lmb_alloc_base().
In doing so it reintroduced the bug fixed by changeset
eea89e13a9 ("[LMB]: Fix bug in
__lmb_alloc_base().").
This puts it back.
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (202 commits)
[POWERPC] Fix compile breakage for 64-bit UP configs
[POWERPC] Define copy_siginfo_from_user32
[POWERPC] Add compat handler for PTRACE_GETSIGINFO
[POWERPC] i2c: Fix build breakage introduced by OF helpers
[POWERPC] Optimize fls64() on 64-bit processors
[POWERPC] irqtrace support for 64-bit powerpc
[POWERPC] Stacktrace support for lockdep
[POWERPC] Move stackframe definitions to common header
[POWERPC] Fix device-tree locking vs. interrupts
[POWERPC] Make pci_bus_to_host()'s struct pci_bus * argument const
[POWERPC] Remove unused __max_memory variable
[POWERPC] Simplify xics direct/lpar irq_host setup
[POWERPC] Use pseries_setup_i8259_cascade() in pseries_mpic_init_IRQ()
[POWERPC] Turn xics_setup_8259_cascade() into a generic pseries_setup_i8259_cascade()
[POWERPC] Move xics_setup_8259_cascade() into platforms/pseries/setup.c
[POWERPC] Use asm-generic/bitops/find.h in bitops.h
[POWERPC] 83xx: mpc8315 - fix USB UTMI Host setup
[POWERPC] 85xx: Fix the size of qe muram for MPC8568E
[POWERPC] 86xx: mpc86xx_hpcn - Temporarily accept old dts node identifier.
[POWERPC] 86xx: mark functions static, other minor cleanups
...
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6: (36 commits)
SCSI: convert struct class_device to struct device
DRM: remove unused dev_class
IB: rename "dev" to "srp_dev" in srp_host structure
IB: convert struct class_device to struct device
memstick: convert struct class_device to struct device
driver core: replace remaining __FUNCTION__ occurrences
sysfs: refill attribute buffer when reading from offset 0
PM: Remove destroy_suspended_device()
Firmware: add iSCSI iBFT Support
PM: Remove legacy PM (fix)
Kobject: Replace list_for_each() with list_for_each_entry().
SYSFS: Explicitly include required header file slab.h.
Driver core: make device_is_registered() work for class devices
PM: Convert wakeup flag accessors to inline functions
PM: Make wakeup flags available whenever CONFIG_PM is set
PM: Fix misuse of wakeup flag accessors in serial core
Driver core: Call device_pm_add() after bus_add_device() in device_add()
PM: Handle device registrations during suspend/resume
block: send disk "change" event for rescan_partitions()
sysdev: detect multiple driver registrations
...
Fixed trivial conflict in include/linux/memory.h due to semaphore header
file change (made irrelevant by the change to mutex).
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel: (62 commits)
sched: build fix
sched: better rt-group documentation
sched: features fix
sched: /debug/sched_features
sched: add SCHED_FEAT_DEADLINE
sched: debug: show a weight tree
sched: fair: weight calculations
sched: fair-group: de-couple load-balancing from the rb-trees
sched: fair-group scheduling vs latency
sched: rt-group: optimize dequeue_rt_stack
sched: debug: add some debug code to handle the full hierarchy
sched: fair-group: SMP-nice for group scheduling
sched, cpuset: customize sched domains, core
sched, cpuset: customize sched domains, docs
sched: prepatory code movement
sched: rt: multi level group constraints
sched: task_group hierarchy
sched: fix the task_group hierarchy for UID grouping
sched: allow the group scheduler to have multiple levels
sched: mix tasks and groups
...
Use the more concise list_for_each_entry(), which allows for the
deletion of the to_kobj() routine at the same time.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add warnings to kobject_put() to catch kobjects that are cleaned up but
were never initialized to begin with.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a new function cpumask_scnprintf_len() to return the number of
characters needed to display "len" cpumask bits. The current method
of allocating NR_CPUS bytes is incorrect as what's really needed is
9 characters per 32-bit word of cpumask bits (8 hex digits plus the
seperator [','] or the terminating NULL.) This function provides the
caller the means to allocate the correct string length.
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There have been a few oopses caused by 'struct file's with NULL f_vfsmnts.
There was also a set of potentially missed mnt_want_write()s from
dentry_open() calls.
This patch provides a very simple debugging framework to catch these kinds of
bugs. It will WARN_ON() them, but should stop us from having any oopses or
mnt_writer count imbalances.
I'm quite convinced that this is a good thing because it found bugs in the
stuff I was working on as soon as I wrote it.
[hch: made it conditional on a debug option.
But it's still a little bit too ugly]
[hch: merged forced remount r/o fix from Dave and akpm's fix for the fix]
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.26: (1090 commits)
[NET]: Fix and allocate less memory for ->priv'less netdevices
[IPV6]: Fix dangling references on error in fib6_add().
[NETLABEL]: Fix NULL deref in netlbl_unlabel_staticlist_gen() if ifindex not found
[PKT_SCHED]: Fix datalen check in tcf_simp_init().
[INET]: Uninline the __inet_inherit_port call.
[INET]: Drop the inet_inherit_port() call.
SCTP: Initialize partial_bytes_acked to 0, when all of the data is acked.
[netdrvr] forcedeth: internal simplifications; changelog removal
phylib: factor out get_phy_id from within get_phy_device
PHY: add BCM5464 support to broadcom PHY driver
cxgb3: Fix __must_check warning with dev_dbg.
tc35815: Statistics cleanup
natsemi: fix MMIO for PPC 44x platforms
[TIPC]: Cleanup of TIPC reference table code
[TIPC]: Optimized initialization of TIPC reference table
[TIPC]: Remove inlining of reference table locking routines
e1000: convert uint16_t style integers to u16
ixgb: convert uint16_t style integers to u16
sb1000.c: make const arrays static
sb1000.c: stop inlining largish static functions
...
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (137 commits)
[SCSI] iscsi: bidi support for iscsi_tcp
[SCSI] iscsi: bidi support at the generic libiscsi level
[SCSI] iscsi: extended cdb support
[SCSI] zfcp: Fix error handling for blocked unit for send FCP command
[SCSI] zfcp: Remove zfcp_erp_wait from slave destory handler to fix deadlock
[SCSI] zfcp: fix 31 bit compile warnings
[SCSI] bsg: no need to set BSG_F_BLOCK bit in bsg_complete_all_commands
[SCSI] bsg: remove minor in struct bsg_device
[SCSI] bsg: use better helper list functions
[SCSI] bsg: replace kobject_get with blk_get_queue
[SCSI] bsg: takes a ref to struct device in fops->open
[SCSI] qla1280: remove version check
[SCSI] libsas: fix endianness bug in sas_ata
[SCSI] zfcp: fix compiler warning caused by poking inside new semaphore (linux-next)
[SCSI] aacraid: Do not describe check_reset parameter with its value
[SCSI] aacraid: Fix down_interruptible() to check the return value
[SCSI] sun3_scsi_vme: add MODULE_LICENSE
[SCSI] st: rename flush_write_buffer()
[SCSI] tgt: use KMEM_CACHE macro
[SCSI] initio: fix big endian problems for auto request sense
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: (43 commits)
firewire: cleanups
firewire: fix synchronization of gap counts
firewire: wait until PHY configuration packet was transmitted (fix bus reset loop)
firewire: remove unused struct member
firewire: use bitwise and to get reg in handle_registers
firewire: replace more hex values with defined csr constants
firewire: reread config ROM when device reset the bus
firewire: replace static ROM cache by allocated cache
firewire: fw-ohci: work around generation bug in TI controllers (fix AV/C and more)
firewire: fw-ohci: extend logging of bus generations and node ID
firewire: fw-ohci: conditionally log busReset interrupts
firewire: fw-ohci: don't append to AT context when it's not active
firewire: fw-ohci: log regAccessFail events
firewire: fw-ohci: make sure HCControl register LPS bit is set
firewire: fw-ohci: missing PPC PMac feature calls in failure path
firewire: fw-ohci: untangle a mixed unsigned/signed expression
firewire: debug interrupt events
firewire: fw-ohci: catch self_id_count == 0
firewire: fw-ohci: add self ID error check
firewire: fw-ohci: refactor probe, remove, suspend, resume
...
This way firewire-ohci can be used for remote debugging like ohci1394.
Version with amendment from Fri, 11 Apr 2008 00:08:08 +0200.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Bernhard Kaindl <bk@suse.de>
* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
Remove DEBUG_SEMAPHORE from Kconfig
Improve semaphore documentation
Simplify semaphore implementation
Add down_timeout and change ACPI to use it
Introduce down_killable()
Generic semaphore implementation
Add semaphore.h to kernel_lock.c
Fix quota.h includes
This patch adds in the ability to compile the kgdb internal test
string into the kernel so as to run the tests at boot without changing
the kernel boot arguments. This patch also changes all the error
paths to invoke WARN_ON(1) which will emit the line number of the file
and dump the kernel stack when an error occurs.
You can disable the tests in a kernel that is built this way
using "kgdbts="
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds regression tests for testing the kgdb core and arch
specific implementation.
The kgdb test suite is designed to be built into the kernel and not as
a module because it uses a number of low level kernel and kgdb
primitives which should not be exported externally.
The kgdb test suite is designed as a KGDB I/O module which
simulates the communications that a debugger would have with kgdb.
The tests are broken up in to a line by line and referenced here as
a "get" which is kgdb requesting input and "put" which is kgdb
sending a response.
The kgdb suite can be invoked from the kernel command line
arguments system or executed dynamically at run time. The test
suite uses the variable "kgdbts" to obtain the information about
which tests to run and to configure the verbosity level. The
following are the various characters you can use with the kgdbts=
line:
When using the "kgdbts=" you only choose one of the following core
test types:
A = Run all the core tests silently
V1 = Run all the core tests with minimal output
V2 = Run all the core tests in debug mode
You can also specify optional tests:
N## = Go to sleep with interrupts of for ## seconds
to test the HW NMI watchdog
F## = Break at do_fork for ## iterations
S## = Break at sys_open for ## iterations
NOTE: that the do_fork and sys_open tests are mutually exclusive.
To invoke the kgdb test suite from boot you use a kernel start
argument as follows:
kgdbts=V1 kgdbwait
Or if you wanted to perform the NMI test for 6 seconds and do_fork
test for 100 forks, you could use:
kgdbts=V1N6F100 kgdbwait
The test suite can also be invoked at run time with:
echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
Or as another example:
echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts
When developing a new kgdb arch specific implementation or
using these tests for the purpose of regression testing,
several invocations are required.
1) Boot with the test suite enabled by using the kernel arguments
"kgdbts=V1F100 kgdbwait"
## If kgdb arch specific implementation has NMI use
"kgdbts=V1N6F100
2) After the system boot run the basic test.
echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts
3) Run the concurrency tests. It is best to use n+1
while loops where n is the number of cpus you have
in your system. The example below uses only two
loops.
## This tests break points on sys_open
while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
fg # and hit control-c
fg # and hit control-c
## This tests break points on do_fork
while [ 1 ] ; do date > /dev/null ; done &
while [ 1 ] ; do date > /dev/null ; done &
echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
fg # and hit control-c
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kgdb core code. Handles the protocol and the arch details.
[ mingo@elte.hu: heavily modified, simplified and cleaned up. ]
[ xemul@openvz.org: use find_task_by_pid_ns ]
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Alpha and FRV mutexes had an option to print lots of debugging messages
in their semaphore implementation. This feature has not been carried
over to the generic semaphores, so remove the stale Kconfig option.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
kernel_lock.c uses DECLARE_MUTEX, up() and down() without explicitly
including asm/semaphore.h. This is fragile and leaves it vulnerable
to breakage during header reorganisations.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
There is a potential bug in __lmb_alloc_base where we subtract `size'
from the base address of a reserved region without checking whether
the subtraction could wrap around and produce a very large unsigned
value. In fact it probably isn't possible to hit the bug in practice
since it would only occur in the situation where we can't satisfy the
allocation request and there is a reserved region starting at 0.
This fixes the potential bug by breaking out of the loop when we get
to the point where the base of the reserved region is less than the
size requested. This also restructures the loop to be a bit easier to
follow.
The same logic got copied into lmb_alloc_nid_unreserved, so this makes
a similar change there. Here the bug is more likely to be hit because
the outer loop (in lmb_alloc_nid) goes through the memory regions in
increasing order rather than decreasing order as __lmb_alloc_base
does, and we are therefore more likely to hit the case where we are
testing against a reserved region with a base address of 0.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This makes no semantic changes. It fixes the whitespace and formatting
a bit, gets rid of a local DBG macro and uses the equivalent pr_debug
instead, and restructures one while loop that had a function call and
assignment in the condition to be a bit more readable. Some comments
about functions being called with relocation disabled were also removed
as they would just be confusing to most readers now that the code is
in lib/.
Signed-off-by: Paul Mackerras <paulus@samba.org>
A variant of lmb_alloc() that tries to allocate memory on a specified
NUMA node 'nid' but falls back to normal lmb_alloc() if that fails.
The caller provides a 'nid_range' function pointer which assists the
allocator. It is given args 'start', 'end', and pointer to integer
'this_nid'.
It places at 'this_nid' the NUMA node id that corresponds to 'start',
and returns the end address within 'start' to 'end' at which memory
assosciated with 'nid' ends.
This callback allows a platform to use lmb_alloc_nid() in just
about any context, even ones in which early_pfn_to_nid() might
not be working yet.
This function will be used by the NUMA setup code on sparc64, and also
it can be used by powerpc, replacing it's hand crafted
"careful_allocation()" function in arch/powerpc/mm/numa.c
If x86 ever converts it's NUMA support over to using the LMB helpers,
it can use this too as it has something entirely similar.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
count_partial() is used by both slabinfo and the sysfs proc support. Move
the function directly before the beginning of the sysfs code so that it can
be easily found. Rework the preprocessor conditional to take into account
that slub sysfs support depends on CONFIG_SYSFS *and* CONFIG_SLUB_DEBUG.
Make CONFIG_SLUB_STATS depend on CONFIG_SLUB_DEBUG and CONFIG_SYSFS. There
is no point of keeping statistics if no one can restrive them.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
