If a filesystem supports POSIX ACL's, the VFS layer expects the filesystem
to do POSIX ACL checks on any files not owned by the caller, and it does
this for every single pathname component that it looks up.
That obviously can be pretty expensive if the filesystem isn't careful
about it, especially with locking. That's doubly sad, since the common
case tends to be that there are no ACL's associated with the files in
question.
ext3 already caches the ACL data so that it doesn't have to look it up
over and over again, but it does so by taking the inode->i_lock spinlock
on every lookup. Which is a noticeable overhead even if it's a private
lock, especially on CPU's where the serialization is expensive (eg Intel
Netburst aka 'P4').
For the special case of not actually having any ACL's, all that locking is
unnecessary. Even if somebody else were to be changing the ACL's on
another CPU, we simply don't care - if we've seen a NULL ACL, we might as
well use it.
So just load the ACL speculatively without any locking, and if it was
NULL, just use it. If it's non-NULL (either because we had a cached
entry, or because the cache hasn't been filled in at all), it means that
we'll need to get the lock and re-load it properly.
This is noticeable even on Nehalem, which does locking quite well (much
better than P4). From lmbench:
Processor, Processes - times in microseconds - smaller is better
--------------------------------------------------------------------
Host OS Mhz null null open slct fork exec sh
call I/O stat clos TCP proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ----
- before:
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.45 2.18 69.1 273. 1141
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.48 2.28 69.9 253. 1140
nehalem.l Linux 2.6.30- 3193 0.04 0.10 0.95 1.42 2.19 68.6 284. 1141
- after:
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.44 2.12 68.3 282. 1094
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.20 67.0 308. 1123
nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.36 67.4 293. 1148
where you can see what appears to be a roughly 3% improvement in stat
and open/close latencies from just the removal of the locking overhead.
Of course, this only matters for files you don't own (the owner never
needs to do the ACL checks), but that's the common case for libraries,
header files, and executables. As well as for the base components of any
absolute pathname, even if you are the owner of the final file.
[ At some point we probably want to move this ACL caching logic entirely
into the VFS layer (and only call down to the filesystem when
uncached), but in the meantime this improves ext3 a bit.
A similar fix to btrfs makes a much bigger difference (15x improvement
in lmbench) due to broken caching. ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'timers-for-linus-migration' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
timers: Logic to move non pinned timers
timers: /proc/sys sysctl hook to enable timer migration
timers: Identifying the existing pinned timers
timers: Framework for identifying pinned timers
timers: allow deferrable timers for intervals tv2-tv5 to be deferred
Fix up conflicts in kernel/sched.c and kernel/timer.c manually
* 'timers-for-linus-clockevents' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
clockevent: export register_device and delta2ns
clockevents: tick_broadcast_device can become static
* 'timers-for-linus-clocksource' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
clocksource: prevent selection of low resolution clocksourse also for nohz=on
clocksource: sanity check sysfs clocksource changes
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (103 commits)
powerpc: Fix bug in move of altivec code to vector.S
powerpc: Add support for swiotlb on 32-bit
powerpc/spufs: Remove unused error path
powerpc: Fix warning when printing a resource_size_t
powerpc/xmon: Remove unused variable in xmon.c
powerpc/pseries: Fix warnings when printing resource_size_t
powerpc: Shield code specific to 64-bit server processors
powerpc: Separate PACA fields for server CPUs
powerpc: Split exception handling out of head_64.S
powerpc: Introduce CONFIG_PPC_BOOK3S
powerpc: Move VMX and VSX asm code to vector.S
powerpc: Set init_bootmem_done on NUMA platforms as well
powerpc/mm: Fix a AB->BA deadlock scenario with nohash MMU context lock
powerpc/mm: Fix some SMP issues with MMU context handling
powerpc: Add PTRACE_SINGLEBLOCK support
fbdev: Add PLB support and cleanup DCR in xilinxfb driver.
powerpc/virtex: Add ml510 reference design device tree
powerpc/virtex: Add Xilinx ML510 reference design support
powerpc/virtex: refactor intc driver and add support for i8259 cascading
powerpc/virtex: Add support for Xilinx PCI host bridge
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
regulator/max1586: fix V3 gain calculation integer overflow
regulator/max1586: support increased V3 voltage range
regulator: lp3971 - fix driver link error when built-in.
LP3971 PMIC regulator driver (updated and combined version)
regulator: remove driver_data direct access of struct device
regulator: Set MODULE_ALIAS for regulator drivers
regulator: Support list_voltage for fixed voltage regulator
regulator: Move regulator drivers to subsys_initcall()
regulator: build fix for powerpc - renamed show_state
regulator: add userspace-consumer driver
Maxim 1586 regulator driver
ad6561dffa ("module: trim exception table on init
free.") put a bogus trim_init_extable() function into ia64 which didn't compile.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (22 commits)
nilfs2: support contiguous lookup of blocks
nilfs2: add sync_page method to page caches of meta data
nilfs2: use device's backing_dev_info for btree node caches
nilfs2: return EBUSY against delete request on snapshot
nilfs2: modify list of unsupported features in caveats
nilfs2: enable sync_page method
nilfs2: set bio unplug flag for the last bio in segment
nilfs2: allow future expansion of metadata read out via get info ioctl
NILFS2: Pagecache usage optimization on NILFS2
nilfs2: remove nilfs_btree_operations from btree mapping
nilfs2: remove nilfs_direct_operations from direct mapping
nilfs2: remove bmap pointer operations
nilfs2: remove useless b_low and b_high fields from nilfs_bmap struct
nilfs2: remove pointless NULL check of bpop_commit_alloc_ptr function
nilfs2: move get block functions in bmap.c into btree codes
nilfs2: remove nilfs_bmap_delete_block
nilfs2: remove nilfs_bmap_put_block
nilfs2: remove header file for segment list operations
nilfs2: eliminate removal list of segments
nilfs2: add sufile function that can modify multiple segment usages
...
On Thu, May 28, 2009 at 10:59 AM, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote:
> On Thu, May 28, 2009 at 07:15:16AM +0200, Philipp Zabel wrote:
>> The V3 regulator can be configured with an external resistor
>> connected to the feedback pin (R24 in the data sheet) to
>> increase the voltage range.
>>
>> For example, hx4700 has R24 = 3.32 kOhm to achieve a maximum
>> V3 voltage of 1.55 V which is needed for 624 MHz CPU frequency.
>>
>> Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
>
> Looks good.
>
> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Thanks, but it turns out I hit a 32 bit integer overflow in
the gain calculation. I'd like to mend that with the following
patch. Now max_uV could be increased up to 4.294 V, enough to
charge LiPo cells.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
The V3 regulator can be configured with an external resistor
connected to the feedback pin (R24 in the data sheet) to
increase the voltage range.
For example, hx4700 has R24 = 3.32 kOhm to achieve a maximum
V3 voltage of 1.55 V which is needed for 624 MHz CPU frequency.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
lp3971_i2c_remove' referenced in section `.data' of drivers/built-in.o:
defined in discarded section `.devexit.text' of drivers/built-in.o
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This patch adds regulator drivers for National Semiconductors LP3971 PMIC.
This LP3971 PMIC controller has 3 DC/DC voltage converters and 5 low
drop-out (LDO) regulators. LP3971 PMIC controller uses I2C interface.
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
In the near future, the driver core is going to not allow direct access
to the driver_data pointer in struct device. Instead, the functions
dev_get_drvdata() and dev_set_drvdata() should be used. These functions
have been around since the beginning, so are backwards compatible with
all older kernel versions.
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Several of the regulator drivers didn't have MODULE_ALIAS so couldn't be
auto loaded. Add the MODULE_ALIAS in case they do get built as modules.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Regulators need to be available early in init in order to allow them
to be available for consumers when requested. This is generally done
by registering them at subsys_initcall() time but not all regulator
drivers have done that. Convert these drivers to do so in order to
mimimise future support.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This patch fixes the follwing build failure on powerpc:-
> Today's linux-next build (powerpc allyesconfig) failed like this:
>
> drivers/regulator/userspace-consumer.c:43: error: conflicting types
> for 'show_state'
> include/linux/sched.h:273: note: previous definition of 'show_state'
> was here
>
> Caused by commit 5defa2bce704ca4151cfe24e4297aa7797cafd22 ("regulator:
> add userspace-consumer driver") which I have reverted for today.
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
The userspace-consumer driver allows control of voltage and current
regulator state from userspace. This is required for fine-grained
power management of devices that are completely controller by userspace
applications, e.g. a GPS transciever connected to a serial port.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
The Maxim 1586 regulator is a voltage regulator with 2
voltage outputs, specially suitable for Marvell PXA
chips. One output is in the range of required VCC_CORE by
the PXA27x chips, the other in the VCC_USIM required as well
by PXA27x chips.
The chip is controlled through the I2C bus.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Let's use TICKS instead of US, so PSCHED_TICKS2NS and PSCHED_NS2TICKS
(like in PSCHED_TICKS_PER_SEC already) to avoid misleading.
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While doing trie_rebalance(): resize(), inflate(), halve() RCU free
tnodes before updating their parents. It depends on RCU delaying the
real destruction, but if RCU readers start after call_rcu() and before
parent update they could access freed memory.
It is currently prevented with preempt_disable() on the update side,
but it's not safe, except maybe classic RCU, plus it conflicts with
memory allocations with GFP_KERNEL flag used from these functions.
This patch explicitly delays freeing of tnodes by adding them to the
list, which is flushed after the update is finished.
Reported-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On systems where CONFIG_SHMEM is disabled, mounting tmpfs filesystems can
fail when tmpfs options are used. This is because tmpfs creates a small
wrapper around ramfs which rejects unknown options, and ramfs itself only
supports a tiny subset of what tmpfs supports. This makes it pretty hard
to use the same userspace systems across different configuration systems.
As such, ramfs should ignore the tmpfs options when tmpfs is merely a
wrapper around ramfs.
This used to work before commit c3b1b1cbf0 as previously, ramfs would
ignore all options. But now, we get:
ramfs: bad mount option: size=10M
mount: mounting mdev on /dev failed: Invalid argument
Another option might be to restore the previous behavior, where ramfs
simply ignored all unknown mount options ... which is what Hugh prefers.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Matt Mackall <mpm@selenic.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (53 commits)
.gitignore: ignore *.lzma files
kbuild: add generic --set-str option to scripts/config
kbuild: simplify argument loop in scripts/config
kbuild: handle non-existing options in scripts/config
kallsyms: generalize text region handling
kallsyms: support kernel symbols in Blackfin on-chip memory
documentation: make version fix
kbuild: fix a compile warning
gitignore: Add GNU GLOBAL files to top .gitignore
kbuild: fix delay in setlocalversion on readonly source
README: fix misleading pointer to the defconf directory
vmlinux.lds.h update
kernel-doc: cleanup perl script
Improve vmlinux.lds.h support for arch specific linker scripts
kbuild: fix headers_exports with boolean expression
kbuild/headers_check: refine extern check
kbuild: fix "Argument list too long" error for "make headers_check",
ignore *.patch files
Remove bashisms from scripts
menu: fix embedded menu presentation
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
mlx4_core: Don't double-free IRQs when falling back from MSI-X to INTx
IB/mthca: Don't double-free IRQs when falling back from MSI-X to INTx
IB/mlx4: Add strong ordering to local inval and fast reg work requests
IB/ehca: Remove superfluous bitmasks from QP control block
RDMA/cxgb3: Limit fast register size based on T3 limitations
RDMA/cxgb3: Report correct port state and MTU
mlx4_core: Add module parameter for number of MTTs per segment
IB/mthca: Add module parameter for number of MTTs per segment
RDMA/nes: Fix off-by-one bugs in reset_adapter_ne020() and init_serdes()
infiniband: Remove void casts
IB/ehca: Increment version number
IB/ehca: Remove unnecessary memory operations for userspace queue pairs
IB/ehca: Fall back to vmalloc() for big allocations
IB/ehca: Replace vmalloc() with kmalloc() for queue allocation
In addition to KT_DEAD which has limited support for diacriticals,
there is KT_DEAD2 that can support 256 criticals, so let's advertise
it in <linux/keyboard.h>.
This lets userland know abut the drivers/char/keyboard.c function
k_dead2, which supports more than the few trivial ones that k_dead
supports.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If an option does not exist in .config, set it at the end of the file.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc: (25 commits)
atmel-mci: add MCI2 register definitions
atmel-mci: Integrate AT91 specific definition in header file
tmio_mmc: allow compilation for ASIC3
mmc_block: do not DMA to stack
sdhci: Print ADMA status and pointer on debug
tmio_mmc: fix clock setup
tmio_mmc: map SD control registers after enabling the MFD cell
tmio_mmc: correct probe return value for num_resources != 3
tmio_mmc: don't use set_irq_type
tmio_mmc: add bus_shift support
MFD,mmc: tmio_mmc: make HCLK configurable
mmc_spi: don't use EINVAL for possible transmission errors
cb710: more cleanup for the DEBUG case.
sdhci: platform driver for SDHCI
mxcmmc: remove frequency workaround
cb710: handle DEBUG define in Makefile
cb710: add missing parenthesis
cb710: fix printk format string
mmc: Driver for CB710/720 memory card reader (MMC part)
pxamci: add regulator support.
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: fix inverted wheel for bluetooth version of apple mighty mouse
HID: no more reinitializtion is needed in post_reset
HID: hidraw -- fix comment about accepted devices
HID: Multitouch support for the N-Trig touchscreen
HID: add new multitouch and digitizer contants
HID: autocentering support for Logitech Force 3D Pro
HID: fix hid-ff drivers so that devices work even without ff support
HID: force feedback support for SmartJoy PLUS PS2/USB adapter
HID: Wacom Graphire Bluetooth driver
HID: autocentering support for Logitech G25 Racing Wheel
The Blackfin arch has a discontiguous .text layout due to having on-chip
instruction memory and no virtual memory support. As such, we need to
add explicit checks for these additional .text regions.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (417 commits)
MAINTAINERS: EB110ATX is not ebsa110
MAINTAINERS: update Eric Miao's email address and status
fb: add support of LCD display controller on pxa168/910 (base layer)
[ARM] 5552/1: ep93xx get_uart_rate(): use EP93XX_SYSCON_PWRCNT and EP93XX_SYSCON_PWRCN
[ARM] pxa/sharpsl_pm: zaurus needs generic pxa suspend/resume routines
[ARM] 5544/1: Trust PrimeCell resource sizes
[ARM] pxa/sharpsl_pm: cleanup of gpio-related code.
[ARM] pxa/sharpsl_pm: drop set_irq_type calls
[ARM] pxa/sharpsl_pm: merge pxa-specific code into generic one
[ARM] pxa/sharpsl_pm: merge the two sharpsl_pm.c since it's now pxa specific
[ARM] sa1100: remove unused collie_pm.c
[ARM] pxa: fix the conflicting non-static declarations of global_gpios[]
[ARM] 5550/1: Add default configure file for w90p910 platform
[ARM] 5549/1: Add clock api for w90p910 platform.
[ARM] 5548/1: Add gpio api for w90p910 platform
[ARM] 5551/1: Add multi-function pin api for w90p910 platform.
[ARM] Make ARM_VIC_NR depend on ARM_VIC
[ARM] 5546/1: ARM PL022 SSP/SPI driver v3
ARM: OMAP4: SMP: Update defconfig for OMAP4430
ARM: OMAP4: SMP: Enable SMP support for OMAP4430
...
The Makefiles in the build directories use the internal make variable
MAKEFILE_LIST which is available from make 3.80 only. (The patch would be
valid back to 2.6.25)
Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
gcc-4.4.1:
HOSTCC scripts/basic/fixdep
scripts/basic/fixdep.c: In function 'traps':
scripts/basic/fixdep.c:377: warning: dereferencing type-punned pointer will break strict-aliasing rules
scripts/basic/fixdep.c:379: warning: dereferencing type-punned pointer will break strict-aliasing rules
(Apparently -fno-strict-aliasing will fix this too)
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
When both MSI-X and legacy INTx fail to generate an interrupt, the
driver frees the MSI-X interrupts twice. Fix this by clearing the
have_irq flag for the MSI-X interrupts when they are freed the first
time. This is the same bug that was reported in ib_mthca by Yinghai
Lu <yhlu.kernel@gmail.com>.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Ignore GPATH, GRTAGS, GSYMS, and GTAGS generated by GNU GLOBAL.
Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Do not update index on read only media.
Idea published by Christian Kujau <lists@nerdbynature.de>.
Cc: Nico Schottelius <nico@ikn.schottelius.org>
Cc: Christian Kujau <lists@nerdbynature.de>
Updated after review by Tim Abbott.
- Use HEAD_TEXT_SECTION
- Drop use of section-names.h and delete file
- Introduce EXIT_CALL
Deleting section-names.h required a few simple
updates of init.h
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Tim Abbott <tabbott@ksplice.com>
