Commit Graph

189 Commits

Author SHA1 Message Date
Randy Dunlap 99657c7857 kernel hacking: move STRIP_ASM_SYMS from General
Sam suggested moving STRIP_ASM_SYMS into the Kernel hacking menu
from the General Setup menu.  It makes more sense there.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-09-20 12:27:42 +02:00
Linus Torvalds 723e9db7a4 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (134 commits)
  powerpc/nvram: Enable use Generic NVRAM driver for different size chips
  powerpc/iseries: Fix oops reading from /proc/iSeries/mf/*/cmdline
  powerpc/ps3: Workaround for flash memory I/O error
  powerpc/booke: Don't set DABR on 64-bit BookE, use DAC1 instead
  powerpc/perf_counters: Reduce stack usage of power_check_constraints
  powerpc: Fix bug where perf_counters breaks oprofile
  powerpc/85xx: Fix SMP compile error and allow NULL for smp_ops
  powerpc/irq: Improve nanodoc
  powerpc: Fix some late PowerMac G5 with PCIe ATI graphics
  powerpc/fsl-booke: Use HW PTE format if CONFIG_PTE_64BIT
  powerpc/book3e: Add missing page sizes
  powerpc/pseries: Fix to handle slb resize across migration
  powerpc/powermac: Thermal control turns system off too eagerly
  powerpc/pci: Merge ppc32 and ppc64 versions of phb_scan()
  powerpc/405ex: support cuImage via included dtb
  powerpc/405ex: provide necessary fixup function to support cuImage
  powerpc/40x: Add support for the ESTeem 195E (PPC405EP) SBC
  powerpc/44x: Add Eiger AMCC (AppliedMicro) PPC460SX evaluation board support.
  powerpc/44x: Update Arches defconfig
  powerpc/44x: Update Arches dts
  ...

Fix up conflicts in drivers/char/agp/uninorth-agp.c
2009-09-15 09:51:09 -07:00
Linus Torvalds ada3fa1505 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
  powerpc64: convert to dynamic percpu allocator
  sparc64: use embedding percpu first chunk allocator
  percpu: kill lpage first chunk allocator
  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
  percpu: update embedding first chunk allocator to handle sparse units
  percpu: use group information to allocate vmap areas sparsely
  vmalloc: implement pcpu_get_vm_areas()
  vmalloc: separate out insert_vmalloc_vm()
  percpu: add chunk->base_addr
  percpu: add pcpu_unit_offsets[]
  percpu: introduce pcpu_alloc_info and pcpu_group_info
  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
  percpu: add @align to pcpu_fc_alloc_fn_t
  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
  percpu: drop @static_size from first chunk allocators
  percpu: generalize first chunk allocator selection
  percpu: build first chunk allocators selectively
  percpu: rename 4k first chunk allocator to page
  percpu: improve boot messages
  percpu: fix pcpu_reclaim() locking
  ...

Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-15 09:39:44 -07:00
Linus Torvalds eee2775d99 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits)
  rcu: Move end of special early-boot RCU operation earlier
  rcu: Changes from reviews: avoid casts, fix/add warnings, improve comments
  rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees
  rcu: Remove lockdep annotations from RCU's _notrace() API members
  rcu: Add #ifdef to suppress __rcu_offline_cpu() warning in !HOTPLUG_CPU builds
  rcu: Add CPU-offline processing for single-node configurations
  rcu: Add "notrace" to RCU function headers used by ftrace
  rcu: Remove CONFIG_PREEMPT_RCU
  rcu: Merge preemptable-RCU functionality into hierarchical RCU
  rcu: Simplify rcu_pending()/rcu_check_callbacks() API
  rcu: Use debugfs_remove_recursive() simplify code.
  rcu: Merge per-RCU-flavor initialization into pre-existing macro
  rcu: Fix online/offline indication for rcudata.csv trace file
  rcu: Consolidate sparse and lockdep declarations in include/linux/rcupdate.h
  rcu: Renamings to increase RCU clarity
  rcu: Move private definitions from include/linux/rcutree.h to kernel/rcutree.h
  rcu: Expunge lingering references to CONFIG_CLASSIC_RCU, optimize on !SMP
  rcu: Delay rcu_barrier() wait until beginning of next CPU-hotunplug operation.
  rcu: Fix typo in rcu_irq_exit() comment header
  rcu: Make rcupreempt_trace.c look at offline CPUs
  ...
2009-09-11 13:20:18 -07:00
David Howells e0e817392b CRED: Add some configurable debugging [try #6]
Add a config option (CONFIG_DEBUG_CREDENTIALS) 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 (which includes
all references, not just those from task_structs).

Furthermore, if SELinux is enabled, the code also checks that the security
pointer in the cred struct is never seen to be invalid.

This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
kernel thread on seeing cred->security be a NULL pointer (it appears that the
credential struct has been previously released):

	http://www.kerneloops.org/oops.php?number=252883

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 21:29:01 +10:00
Paul E. McKenney 6b3ef48adf rcu: Remove CONFIG_PREEMPT_RCU
Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no
further need for CONFIG_PREEMPT_RCU.  Remove it, along with
whatever subtle bugs it may (or may not) contain.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <125097461396-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23 10:32:40 +02:00
Paul E. McKenney f41d911f8c rcu: Merge preemptable-RCU functionality into hierarchical RCU
Create a kernel/rcutree_plugin.h file that contains definitions
for preemptable RCU (or, under the #else branch of the #ifdef,
empty definitions for the classic non-preemptable semantics).
These definitions fit into plugins defined in kernel/rcutree.c
for this purpose.

This variant of preemptable RCU uses a new algorithm whose
read-side expense is roughly that of classic hierarchical RCU
under CONFIG_PREEMPT. This new algorithm's update-side expense
is similar to that of classic hierarchical RCU, and, in absence
of read-side preemption or blocking, is exactly that of classic
hierarchical RCU.  Perhaps more important, this new algorithm
has a much simpler implementation, saving well over 1,000 lines
of code compared to mainline's implementation of preemptable
RCU, which will hopefully be retired in favor of this new
algorithm.

The simplifications are obtained by maintaining per-task
nesting state for running tasks, and using a simple
lock-protected algorithm to handle accounting when tasks block
within RCU read-side critical sections, making use of lessons
learned while creating numerous user-level RCU implementations
over the past 18 months.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12509746134003-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23 10:32:40 +02:00
Michael Ellerman bbdc16f58e kmemleak: Allow kmemleak to be built on powerpc
Very lightly tested, doesn't crash the kernel.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-20 10:29:23 +10:00
Tejun Heo c43768cbb7 Merge branch 'master' into for-next
Pull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix
changes.  As alpha in percpu tree uses 'weak' attribute instead of
inline assembly, there's no need for __used attribute.

Conflicts:
	arch/alpha/include/asm/percpu.h
	arch/mn10300/kernel/vmlinux.lds.S
	include/linux/percpu-defs.h
2009-07-04 07:13:18 +09:00
Catalin Marinas a9d9058aba kmemleak: Allow the early log buffer to be configurable.
(feature suggested by Sergey Senozhatsky)

Kmemleak needs to track all the memory allocations but some of these
happen before kmemleak is initialised. These are stored in an internal
buffer which may be exceeded in some kernel configurations. This patch
adds a configuration option with a default value of 400 and also removes
the stack dump when the early log buffer is exceeded.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
2009-06-25 10:16:13 +01:00
Tejun Heo 7c756e6e19 percpu: implement optional weak percpu definitions
Some archs (alpha and s390) need to use weak definitions for percpu
variables in modules so that the compiler generates external
references for them.

This patch implements weak percpu definitions which arch can enable by
defining ARCH_NEEDS_WEAK_PER_CPU in arch percpu header file.  This
weak definition adds 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 these restrictions are observed in generic code, config
option DEBUG_FORCE_WEAK_PER_CPU enables weak percpu definitions for
all cases.

This patch is inspired by Ivan Kokshaysky's alpha percpu patch.

[ Impact: stricter rules for percpu variables, one more debug config option ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Howells <dhowells@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
2009-06-24 15:13:50 +09:00
Catalin Marinas bf96d1e3e7 kmemleak: Do not force the slab debugging Kconfig options
Selecting DEBUG_SLAB or SLUB_DEBUG by the KMEMLEAK menu entry may cause
issues with other dependencies (KMEMCHECK). These configuration options
aren't strictly needed by kmemleak but they may increase the chances of
finding leaks. This patch also updates the KMEMLEAK config entry help
text.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-23 14:40:27 +01:00
Linus Torvalds 8b12e2505a Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Select frame pointers on x86
  dma-debug: be more careful when building reference entries
  dma-debug: check for sg_call_ents in best-fit algorithm too
2009-06-21 13:13:53 -07:00
Peter Zijlstra 00540e5d54 lockdep: Select frame pointers on x86
x86 stack traces are a piece of crap without frame pointers, and its not
like the 'performance gain' of not having stack pointers matters when you
selected lockdep.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <new-submission>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-21 10:14:33 +02:00
Pekka Enberg 0a4af3b093 kmemcheck: make kconfig accessible for other architectures
The Kconfig options of kmemcheck are hidden under arch/x86 which makes porting
to other architectures harder. To fix that, move the Kconfig bits to
lib/Kconfig.kmemcheck and introduce a CONFIG_HAVE_ARCH_KMEMCHECK config option
that architectures can define.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-15 15:49:17 +02:00
Vegard Nossum 7d46d9e6db kmemcheck: enable in the x86 Kconfig
let it rip!

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
2009-06-15 15:49:15 +02:00
Catalin Marinas 0822ee4ac1 kmemleak: Simple testing module for kmemleak
This patch adds a loadable module that deliberately leaks memory. It
is used for testing various memory leaking scenarios.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-06-11 17:04:19 +01:00
Catalin Marinas 3bba00d7bd kmemleak: Enable the building of the memory leak detector
This patch adds the Kconfig.debug and Makefile entries needed for
building kmemleak into the kernel.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-06-11 17:04:18 +01:00
Jason Baron fe0e2bb9b3 Remove old PRINTK_DEBUG config item
On Tue, Apr 21, 2009 at 01:55:53PM +0200, Stefan Richter wrote:
> Robert P. J. Day wrote:
> >   lib/Kconfig.debug:      select PRINTK_DEBUG
> > 
> > should that perhaps refer to "DYNAMIC_PRINTK_DEBUG"?  since there is
> > no such thing as a PRINTK_DEBUG Kconfig variable.
> 
> Looks like a rudiment from an earlier version of Jason's "driver core:
> basic infrastructure for per-module dynamic debug messages",
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=346e15beb5343c2eb8216d820f2ed8f150822b08
> Search an LKML archive for '+#ifdef CONFIG_PRINTK_DEBUG'.
> 
> Jason, should it be deleted or replaced by something?

We re-named 'DYNAMIC_PRINTK_DEBUG' to 'DYNAMIC_DEBUG' in 2.6.30....
'PRINTK_DEBUG' as pointed out never existed. So, it appears to be
extraneous, and should be removed. thanks for pointing it out.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-08 19:22:21 -07:00
Heiko Carstens 75ee034add [S390] omit frame pointers on s390 when possible
Always omit frame pointers on s390. They aren't too useful for the
kernel since we have already the kernel stack backchain which allows
us to walk the kernel stack.
So eleminate the extra code for frame pointers. Only allow the extra
code for the function tracer since the gcc compile options -pg and
-fomit-frame-pointer are incompatible.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-04-23 13:58:18 +02:00
Ingo Molnar 5e34437840 Merge branch 'linus' into core/softlockup
Conflicts:
	kernel/sysctl.c
2009-04-07 11:15:40 +02:00
Ingo Molnar 77d05632ba softlockup: make DETECT_HUNG_TASK default depend on DETECT_SOFTLOCKUP
Don't offer a default-y option when the user has turned off
CONFIG_DETECT_SOFTLOCKUP already.

Do offer it as 'y' only if DETECT_SOFTLOCKUP is on already.

This makes it match previous behavior - where the hung-task check was
embedded i CONFIG_DETECT_SOFTLOCKUP code.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-07 08:55:36 +02:00
Akinobu Mita 6a11f75b6a generic debug pagealloc
CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390.  This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().

This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:13 -07:00
Linus Torvalds 712b0006bf Merge branch 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits)
  dma-debug: make memory range checks more consistent
  dma-debug: warn of unmapping an invalid dma address
  dma-debug: fix dma_debug_add_bus() definition for !CONFIG_DMA_API_DEBUG
  dma-debug/x86: register pci bus for dma-debug leak detection
  dma-debug: add a check dma memory leaks
  dma-debug: add checks for kernel text and rodata
  dma-debug: print stacktrace of mapping path on unmap error
  dma-debug: Documentation update
  dma-debug: x86 architecture bindings
  dma-debug: add function to dump dma mappings
  dma-debug: add checks for sync_single_sg_*
  dma-debug: add checks for sync_single_range_*
  dma-debug: add checks for sync_single_*
  dma-debug: add checking for [alloc|free]_coherent
  dma-debug: add add checking for map/unmap_sg
  dma-debug: add checking for map/unmap_page/single
  dma-debug: add core checking functions
  dma-debug: add debugfs interface
  dma-debug: add kernel command line parameters
  dma-debug: add initialization code
  ...

Fix trivial conflicts due to whitespace changes in arch/x86/kernel/pci-nommu.c
2009-03-30 13:41:00 -07:00
Ingo Molnar b0d44c0dbb Merge branch 'linus' into core/iommu
Conflicts:
	arch/x86/Kconfig
2009-03-28 23:05:50 +01:00
Russell King ed40d0c472 Merge branch 'origin' into devel
Conflicts:
	sound/soc/pxa/pxa2xx-i2s.c
2009-03-28 20:29:51 +00:00
Jason Baron 86151fdf38 dynamic debug: update docs
updates the documentation for 'dynamic debug' feature.

Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:38:27 -07:00
Jason Baron e9d376f0fa dynamic debug: combine dprintk and dynamic printk
This patch combines Greg Bank's dprintk() work with the existing dynamic
printk patchset, we are now calling it 'dynamic debug'.

The new feature of this patchset is a richer /debugfs control file interface,
(an example output from my system is at the bottom), which allows fined grained
control over the the debug output. The output can be controlled by function,
file, module, format string, and line number.

for example, enabled all debug messages in module 'nf_conntrack':

echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control

to disable them:

echo -n 'module nf_conntrack -p' > /mnt/debugfs/dynamic_debug/control

A further explanation can be found in the documentation patch.

Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:38:26 -07:00
Russell King 97fb44eb6b Merge branch 'for-rmk' of git://git.pengutronix.de/git/imx/linux-2.6 into devel
Conflicts:

	arch/arm/mach-at91/gpio.c
2009-03-13 21:44:51 +00:00
Joerg Roedel 5ee00bd469 dma-debug: add Kconfig entry
Impact: add a Kconfig entry for DMA-API debugging

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-03-05 14:36:50 +01:00
Randy Dunlap 152de30bce docsrc: use config instead of menuconfig
BUILD_DOCSRC should be controlled by "config" instead of "menuconfig".
I have no idea how I managed to use "menuconfig" here.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-20 17:57:49 -08:00
Catalin Marinas adf8b37baf [ARM] 5386/2: unwind: Add Makefile and Kconfig entries for ARM stack unwinding
This patch also makes the frame pointer default to y only if
!ARM_UNWIND. LOCKDEP no longer selects FRAME_POINTER if ARM_UNWIND is
enabled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-19 11:30:18 +00:00
Ingo Molnar 871cafcc96 Merge branch 'linus' into core/softlockup 2009-02-12 13:08:57 +01:00
Linus Torvalds 3386c05bdb Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()
2009-01-26 09:47:56 -08:00
Lai Jiangshan 749a440b22 rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
Impact: remove the old CONFIG_RCU_CPU_STALL_DETECTOR

tree_rcu introduce CONFIG_RCU_CPU_STALL_DETECTOR again.

These two are the same exactly except:

 the old one "depends on CLASSIC_RCU"
 the new one "depends on CLASSIC_RCU || TREE_RCU"

This patch remove the old one.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-22 09:29:36 +01:00
Jeff Mahoney 64dec40dde x86: define ARCH_WANT_FRAME_POINTERS
Commit da4276b829 changed a dependency
for FRAME_POINTER from X86 to ARCH_WANT_FRAME_POINTERS, but didn't
actually define it.

This patch adds the definition for ARCH_WANT_FRAME_POINTERS. Without it,
FRAME_POINTER can't be enabled on x86.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 21:15:10 +01:00
Mandeep Singh Baines e162b39a36 softlockup: decouple hung tasks check from softlockup detection
Decoupling allows:

* hung tasks check to happen at very low priority

* hung tasks check and softlockup to be enabled/disabled independently
  at compile and/or run-time

* individual panic settings to be enabled disabled independently
  at compile and/or run-time

* softlockup threshold to be reduced without increasing hung tasks
  poll frequency (hung task check is expensive relative to softlock watchdog)

* hung task check to be zero over-head when disabled at run-time

Signed-off-by: Mandeep Singh Baines <msb@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16 14:06:04 +01:00
Linus Torvalds 3d14bdad40 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (36 commits)
  x86: fix section mismatch warnings in mcheck/mce_amd_64.c
  x86: offer frame pointers in all build modes
  x86: remove duplicated #include's
  x86: k8 numa register active regions later
  x86: update Alan Cox's email addresses
  x86: rename all fields of mpc_table mpc_X to X
  x86: rename all fields of mpc_oemtable oem_X to X
  x86: rename all fields of mpc_bus mpc_X to X
  x86: rename all fields of mpc_cpu mpc_X to X
  x86: rename all fields of mpc_intsrc mpc_X to X
  x86: rename all fields of mpc_lintsrc mpc_X to X
  x86: rename all fields of mpc_iopic mpc_X to X
  x86: irqinit_64.c init_ISA_irqs should be static
  Documentation/x86/boot.txt: payload length was changed to payload_length
  x86: setup_percpu.c fix style problems
  x86: irqinit_64.c fix style problems
  x86: irqinit_32.c fix style problems
  x86: i8259.c fix style problems
  x86: irq_32.c fix style problems
  x86: ioport.c fix style problems
  ...
2009-01-10 06:13:09 -08:00
David Howells 8feae13110 NOMMU: Make VMAs per MM as for MMU-mode linux
Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:

 (1) In SYSV SHM where nattch for a segment does not reflect the number of
     shmat's (and forks) done.

 (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
     exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
     that a VMA might be shared and already have its vm_mm assigned to another
     process or a dead process.

A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.

This patch makes the following additional changes:

 (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
     with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
     each page has a reference on it held by the region.  Anything else that is
     interested in such a page will have to get a reference on it to retain it.
     When the pages are released due to unmapping, each page is passed to
     put_page() and will be freed when the page usage count reaches zero.

 (2) Excess pages are trimmed after an allocation as the allocation must be
     made as a power-of-2 quantity of pages.

 (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
     end up with overlapping VMAs within the tree, the VMA struct address is
     appended to the sort key.

 (4) Non-anonymous VMAs are now added to the backing inode's prio list.

 (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
     the backing region.  The VMA and region structs will be split if
     necessary.

 (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
     segment instead of all the attachments at that addresss.  Multiple
     shmat()'s return the same address under NOMMU-mode instead of different
     virtual addresses as under MMU-mode.

 (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.

 (8) /proc/maps is now the global list of mapped regions, and may list bits
     that aren't actually mapped anywhere.

 (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
     of RAM currently allocated by mmap to hold mappable regions that can't be
     mapped directly.  These are copies of the backing device or file if not
     anonymous.

These changes make NOMMU mode more similar to MMU mode.  The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
2009-01-08 12:04:47 +00:00
Ingo Molnar da4276b829 x86: offer frame pointers in all build modes
CONFIG_FRAME_POINTERS=y results in much better debug info for the
kernel (clear and precise backtraces), with the only drawback being
a ~1% increase in kernel size.

So offer it unconditionally and enable it by default.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-07 11:18:59 +01:00
Linus Torvalds db5e53fbf0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: avoid leaking caches or refcounts on sysfs error
  slab: Fix comment on #endif
  slab: remove GFP_THISNODE clearing from alloc_slabmgmt()
  slub: Add might_sleep_if() to slab_alloc()
  SLUB: failslab support
  slub: Fix incorrect use of loose
  slab: Update the kmem_cache_create documentation regarding the name parameter
  slub: make early_kmem_cache_node_alloc void
  slab: unsigned slabp->inuse cannot be less than 0
  slub - fix get_object_page comment
  SLUB: Replace __builtin_return_address(0) with _RET_IP_.
  SLUB: cleanup - define macros instead of hardcoded numbers
2008-12-30 17:28:09 -08:00
Akinobu Mita 773ff60e84 SLUB: failslab support
Currently fault-injection capability for SLAB allocator is only
available to SLAB. This patch makes it available to SLUB, too.

[penberg@cs.helsinki.fi: unify slab and slub implementations]
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-12-29 11:27:46 +02:00
Ingo Molnar 6638101c11 Merge branches 'core/debugobjects', 'core/iommu', 'core/locking', 'core/printk', 'core/rcu', 'core/resources', 'core/softirq' and 'core/stacktrace' into core/core 2008-12-25 14:06:29 +01:00
Paul E. McKenney 64db4cfff9 "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 21:56:04 +01:00
Ingo Molnar 3ae7020543 debugobjects: add boot parameter default value
Impact: add .config driven boot parameter default value

Right now debugobjects can only be activated if the debug_objects
boot parameter is passed in via the boot command line.

Make this more convenient (and randomizable) by also providing
a .config method. Enable it by default. (DEBUG_OBJECTS itself
is default-off)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26 10:07:06 +01:00
Ingo Molnar b19b3c74c7 Merge branches 'core/debug', 'core/futexes', 'core/locking', 'core/rcu', 'core/signal', 'core/urgent' and 'core/xen' into core/core 2008-11-24 17:44:55 +01:00
Tejun Heo 0e11e342ba block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT
CONFIG_DEBUG_BLOCK_EXT_DEVT can break booting even on some modern
distros.  Add BIG FAT WARNING to keep people at a safe distance.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-17 08:46:56 +02:00
Jason Baron 346e15beb5 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>
2008-10-16 09:24:47 -07:00
Ingo Molnar 8daf14cf56 Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', 'x86/memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2 2008-10-12 15:50:02 +02:00
Linus Torvalds b922df7383 Merge branch 'rcu-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'rcu-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits)
  rcu: RCU-based detection of stalled CPUs for Classic RCU, fix
  rcu: RCU-based detection of stalled CPUs for Classic RCU
  rcu: add rcu_read_lock_sched() / rcu_read_unlock_sched()
  rcu: fix sparse shadowed variable warning
  doc/RCU: fix pseudocode in rcuref.txt
  rcuclassic: fix compiler warning
  rcu: use irq-safe locks
  rcuclassic: fix compilation NG
  rcu: fix locking cleanup fallout
  rcu: remove redundant ACCESS_ONCE definition from rcupreempt.c
  rcu: fix classic RCU locking cleanup lockdep problem
  rcu: trace fix possible mem-leak
  rcu: just rename call_rcu_bh instead of making it a macro
  rcu: remove list_for_each_rcu()
  rcu: fixes to include/linux/rcupreempt.h
  rcu: classic RCU locking and memory-barrier cleanups
  rcu: prevent console flood when one CPU sees another AWOL via RCU
  rcu, debug: detect stalled grace periods, cleanups
  rcu, debug: detect stalled grace periods
  rcu classic: new algorithm for callbacks-processing(v2)
  ...
2008-10-10 13:10:51 -07:00