Pull WW mutex support from Ingo Molnar:
"This tree adds support for wound/wait style locks, which the graphics
guys would like to make use of in the TTM graphics subsystem.
Wound/wait mutexes are used when other multiple lock acquisitions of a
similar type can be done in an arbitrary order. The deadlock handling
used here is called wait/wound in the RDBMS literature: The older
tasks waits until it can acquire the contended lock. The younger
tasks needs to back off and drop all the locks it is currently
holding, ie the younger task is wounded.
See this LWN.net description of W/W mutexes:
https://lwn.net/Articles/548909/
The comments there outline specific usecases for this facility (which
have already been implemented for the DRM tree).
Also see Documentation/ww-mutex-design.txt for more details"
* 'core-mutexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking-selftests: Handle unexpected failures more strictly
mutex: Add more w/w tests to test EDEADLK path handling
mutex: Add more tests to lib/locking-selftest.c
mutex: Add w/w tests to lib/locking-selftest.c
mutex: Add w/w mutex slowpath debugging
mutex: Add support for wound/wait style locks
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
Pull ARM SoC non-cricitical bug fixes from Arnd Bergmann:
"These are various bug fixes that were not considered important enough
for merging into 3.10.
The majority of the ARM fixes are for the OMAP and at91 platforms, and
there is another set of bug fixes for device drivers that resolve
'randconfig' build errors and that the subsystem maintainers either
did not pick up or preferred to get merged through the arm-soc tree."
* tag 'fixes-non-critical-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (43 commits)
ARM: at91/PMC: use at91_usb_rate() for UTMI PLL
ARM: at91/PMC: fix at91sam9n12 USB FS init
ARM: at91/PMC: at91sam9n12 family has a PLLB
ARM: at91/PMC: sama5d3 family doesn't have a PLLB
ARM: tegra: fix section mismatch in tegra_pmc_parse_dt
ARM: mxs: don't select HAVE_PWM
ARM: mxs: stub out mxs_pm_init for !CONFIG_PM
cpuidle: calxeda: select ARM_CPU_SUSPEND
ARM: mvebu: fix length of ethernet registers in mv78260 dtsi
ARM: at91: cpuidle: Fix target_residency
ARM: at91: fix at91_extern_irq usage for non-dt boards
ARM: sirf: use CONFIG_SIRF rather than CONFIG_PRIMA2 where necessary
clocksource: kona: adapt to CLOCKSOURCE_OF_DECLARE change
X.509: do not emit any informational output
mtd: omap2: allow bulding as a module
[SCSI] nsp32: use mdelay instead of large udelay constants
hwrng: bcm2835: fix MODULE_LICENSE tag
ARM: at91: Change the internal SRAM memory type MT_MEMORY_NONCACHED
ARM: at91: Fix link breakage when !CONFIG_PHYLIB
MAINTAINERS: Add exynos filename match to ARM/S5P EXYNOS ARM ARCHITECTURES
...
Pull driver core updates from Greg KH:
"Here's the big driver core merge for 3.11-rc1
Lots of little things, and larger firmware subsystem updates, all
described in the shortlog. Nice thing here is that we finally get rid
of CONFIG_HOTPLUG, after 10+ years, thanks to Stephen Rohtwell (it had
been always on for a number of kernel releases, now it's just
removed)"
* tag 'driver-core-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (27 commits)
driver core: device.h: fix doc compilation warnings
firmware loader: fix another compile warning with PM_SLEEP unset
build some drivers only when compile-testing
firmware loader: fix compile warning with PM_SLEEP set
kobject: sanitize argument for format string
sysfs_notify is only possible on file attributes
firmware loader: simplify holding module for request_firmware
firmware loader: don't export cache_firmware and uncache_firmware
drivers/base: Use attribute groups to create sysfs memory files
firmware loader: fix compile warning
firmware loader: fix build failure with !CONFIG_FW_LOADER_USER_HELPER
Documentation: Updated broken link in HOWTO
Finally eradicate CONFIG_HOTPLUG
driver core: firmware loader: kill FW_ACTION_NOHOTPLUG requests before suspend
driver core: firmware loader: don't cache FW_ACTION_NOHOTPLUG firmware
Documentation: Tidy up some drivers/base/core.c kerneldoc content.
platform_device: use a macro instead of platform_driver_register
firmware: move EXPORT_SYMBOL annotations
firmware: Avoid deadlock of usermodehelper lock at shutdown
dell_rbu: Select CONFIG_FW_LOADER_USER_HELPER explicitly
...
Injects EDEADLK conditions at pseudo-random interval, with
exponential backoff up to UINT_MAX (to ensure that every lock
operation still completes in a reasonable time).
This way we can test the wound slowpath even for ww mutex users
where contention is never expected, and the ww deadlock
avoidance algorithm is only needed for correctness against
malicious userspace. An example would be protecting kernel
modesetting properties, which thanks to single-threaded X isn't
really expected to contend, ever.
I've looked into using the CONFIG_FAULT_INJECTION
infrastructure, but decided against it for two reasons:
- EDEADLK handling is mandatory for ww mutex users and should
never affect the outcome of a syscall. This is in contrast to -ENOMEM
injection. So fine configurability isn't required.
- The fault injection framework only allows to set a simple
probability for failure. Now the probability that a ww mutex acquire
stage with N locks will never complete (due to too many injected
EDEADLK backoffs) is zero. But the expected number of ww_mutex_lock
operations for the completely uncontended case would be O(exp(N)).
The per-acuiqire ctx exponential backoff solution choosen here only
results in O(log N) overhead due to injection and so O(log N * N)
lock operations. This way we can fail with high probability (and so
have good test coverage even for fancy backoff and lock acquisition
paths) without running into patalogical cases.
Note that EDEADLK will only ever be injected when we managed to
acquire the lock. This prevents any behaviour changes for users
which rely on the EALREADY semantics.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: rostedt@goodmis.org
Cc: daniel@ffwll.ch
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130620113117.4001.21681.stgit@patser
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When building a kernel using 'make -s', I expect to see an empty output,
except for build warnings and errors. The build_OID_registry code
always prints one line when run, which is not helpful to most people
building the kernels, and which makes it harder to automatically
check for build warnings.
Let's just remove the one line output.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Unlike kobject_set_name(), the kset_create_and_add() interface does not
provide a way to use format strings, so make sure that the interface
cannot be abused accidentally. It looks like all current callers use
static strings, so there's no existing flaw.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since we have at least one user of this function outside of CONFIG_NET
scope, we have to provide this function independently. The proposed
solution is to move it under lib/net_utils.c with corresponding
configuration variable and select wherever it is needed.
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The umul_ppmm() macro for parisc uses the xmpyu assembler statement
which does calculation via a floating point register.
But usage of floating point registers inside the Linux kernel are not
allowed and gcc will stop compilation due to the -mdisable-fpregs
compiler option.
Fix this by disabling the umul_ppmm() and udiv_qrnnd() macros. The
mpilib will then use the generic built-in implementations instead.
Signed-off-by: Helge Deller <deller@gmx.de>
Pull driver core fixes from Greg Kroah-Hartman:
"Here are 3 tiny driver core fixes for 3.10-rc2.
A needed symbol export, a change to make it easier to track down
offending sysfs files with incorrect attributes, and a klist bugfix.
All have been in linux-next for a while"
* tag 'driver-core-3.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
klist: del waiter from klist_remove_waiters before wakeup waitting process
driver core: print sysfs attribute name when warning about bogus permissions
driver core: export subsys_virtual_register
There is a race between klist_remove and klist_release. klist_remove
uses a local var waiter saved on stack. When klist_release calls
wake_up_process(waiter->process) to wake up the waiter, waiter might run
immediately and reuse the stack. Then, klist_release calls
list_del(&waiter->list) to change previous
wait data and cause prior waiter thread corrupt.
The patch fixes it against kernel 3.9.
Signed-off-by: wang, biao <biao.wang@intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ERROR: "memcpy_fromiovec" [drivers/vhost/vhost_scsi.ko] undefined!
That function is only present with CONFIG_NET. Turns out that
crypto/algif_skcipher.c also uses that outside net, but it actually
needs sockets anyway.
In addition, commit 6d4f0139d6 added
CONFIG_NET dependency to CONFIG_VMCI for memcpy_toiovec, so hoist
that function and revert that commit too.
socket.h already includes uio.h, so no callers need updating; trying
only broke things fo x86_64 randconfig (thanks Fengguang!).
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull block driver updates from Jens Axboe:
"It might look big in volume, but when categorized, not a lot of
drivers are touched. The pull request contains:
- mtip32xx fixes from Micron.
- A slew of drbd updates, this time in a nicer series.
- bcache, a flash/ssd caching framework from Kent.
- Fixes for cciss"
* 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits)
bcache: Use bd_link_disk_holder()
bcache: Allocator cleanup/fixes
cciss: bug fix to prevent cciss from loading in kdump crash kernel
cciss: add cciss_allow_hpsa module parameter
drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions
mtip32xx: Workaround for unaligned writes
bcache: Make sure blocksize isn't smaller than device blocksize
bcache: Fix merge_bvec_fn usage for when it modifies the bvm
bcache: Correctly check against BIO_MAX_PAGES
bcache: Hack around stuff that clones up to bi_max_vecs
bcache: Set ra_pages based on backing device's ra_pages
bcache: Take data offset from the bdev superblock.
mtip32xx: mtip32xx: Disable TRIM support
mtip32xx: fix a smatch warning
bcache: Disable broken btree fuzz tester
bcache: Fix a format string overflow
bcache: Fix a minor memory leak on device teardown
bcache: Documentation updates
bcache: Use WARN_ONCE() instead of __WARN()
bcache: Add missing #include <linux/prefetch.h>
...
- make warning smp-safe
- result of atomic _unless_zero functions should be checked by caller
to avoid use-after-free error
- trivial whitespace fix.
Link: https://lkml.org/lkml/2013/4/12/391
Tested: compile x86, boot machine and run xfstests
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
[ Removed line-break, changed to use WARN_ON_ONCE() - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge rwsem optimizations from Michel Lespinasse:
"These patches extend Alex Shi's work (which added write lock stealing
on the rwsem slow path) in order to provide rwsem write lock stealing
on the fast path (that is, without taking the rwsem's wait_lock).
I have unfortunately been unable to push this through -next before due
to Ingo Molnar / David Howells / Peter Zijlstra being busy with other
things. However, this has gotten some attention from Rik van Riel and
Davidlohr Bueso who both commented that they felt this was ready for
v3.10, and Ingo Molnar has said that he was OK with me pushing
directly to you. So, here goes :)
Davidlohr got the following test results from pgbench running on a
quad-core laptop:
| db_size | clients | tps-vanilla | tps-rwsem |
+---------+----------+----------------+--------------+
| 160 MB | 1 | 5803 | 6906 | + 19.0%
| 160 MB | 2 | 13092 | 15931 |
| 160 MB | 4 | 29412 | 33021 |
| 160 MB | 8 | 32448 | 34626 |
| 160 MB | 16 | 32758 | 33098 |
| 160 MB | 20 | 26940 | 31343 | + 16.3%
| 160 MB | 30 | 25147 | 28961 |
| 160 MB | 40 | 25484 | 26902 |
| 160 MB | 50 | 24528 | 25760 |
------------------------------------------------------
| 1.6 GB | 1 | 5733 | 7729 | + 34.8%
| 1.6 GB | 2 | 9411 | 19009 | + 101.9%
| 1.6 GB | 4 | 31818 | 33185 |
| 1.6 GB | 8 | 33700 | 34550 |
| 1.6 GB | 16 | 32751 | 33079 |
| 1.6 GB | 20 | 30919 | 31494 |
| 1.6 GB | 30 | 28540 | 28535 |
| 1.6 GB | 40 | 26380 | 27054 |
| 1.6 GB | 50 | 25241 | 25591 |
------------------------------------------------------
| 7.6 GB | 1 | 5779 | 6224 |
| 7.6 GB | 2 | 10897 | 13611 | + 24.9%
| 7.6 GB | 4 | 32683 | 33108 |
| 7.6 GB | 8 | 33968 | 34712 |
| 7.6 GB | 16 | 32287 | 32895 |
| 7.6 GB | 20 | 27770 | 31689 | + 14.1%
| 7.6 GB | 30 | 26739 | 29003 |
| 7.6 GB | 40 | 24901 | 26683 |
| 7.6 GB | 50 | 17115 | 25925 | + 51.5%
------------------------------------------------------
(Davidlohr also has one additional patch which further improves
throughput, though I will ask him to send it directly to you as I have
suggested some minor changes)."
* emailed patches from Michel Lespinasse <walken@google.com>:
rwsem: no need for explicit signed longs
x86 rwsem: avoid taking slow path when stealing write lock
rwsem: do not block readers at head of queue if other readers are active
rwsem: implement support for write lock stealing on the fastpath
rwsem: simplify __rwsem_do_wake
rwsem: skip initial trylock in rwsem_down_write_failed
rwsem: avoid taking wait_lock in rwsem_down_write_failed
rwsem: use cmpxchg for trying to steal write lock
rwsem: more agressive lock stealing in rwsem_down_write_failed
rwsem: simplify rwsem_down_write_failed
rwsem: simplify rwsem_down_read_failed
rwsem: move rwsem_down_failed_common code into rwsem_down_{read,write}_failed
rwsem: shorter spinlocked section in rwsem_down_failed_common()
rwsem: make the waiter type an enumeration rather than a bitmask
Linus Torvalds
Maarten Lankhorst
Daniel Vetter
Arnd Bergmann
Greg Kroah-Hartman
Chen Gang
Kees Cook
Andy Shevchenko
Seth Jennings
Helge Deller
Randy Dunlap
wang, biao
Rusty Russell
Davidlohr Bueso
Anatol Pomozov