Linus Torvalds [Fri, 7 Jan 2011 22:53:42 +0000 (14:53 -0800)]
Merge branch 'edac-for-linus' of git://git./linux/kernel/git/bp/bp
* 'edac-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
amd64_edac: Disable DRAM ECC injection on K8
EDAC: Fixup scrubrate manipulation
amd64_edac: Remove two-stage initialization
amd64_edac: Check ECC capabilities initially
amd64_edac: Carve out ECC-related hw settings
amd64_edac: Remove PCI ECS enabling functions
amd64_edac: Remove explicit Kconfig PCI dependency
amd64_edac: Allocate driver instances dynamically
amd64_edac: Rework printk macros
amd64_edac: Rename CPU PCI devices
amd64_edac: Concentrate per-family init even more
amd64_edac: Cleanup the CPU PCI device reservation
amd64_edac: Simplify CPU family detection
amd64_edac: Add per-family init function
amd64_edac: Use cached extended CPU model
amd64_edac: Remove F11h support
Linus Torvalds [Fri, 7 Jan 2011 22:50:50 +0000 (14:50 -0800)]
Merge branch 'for-linus' of git://git390.marist.edu/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (65 commits)
[S390] prevent unneccesary loops_per_jiffy recalculation
[S390] cpuinfo: use get_online_cpus() instead of preempt_disable()
[S390] smp: remove cpu hotplug messages
[S390] mutex: enable spinning mutex on s390
[S390] mutex: Introduce arch_mutex_cpu_relax()
[S390] cio: fix ccwgroup unregistration race condition
[S390] perf: add DWARF register lookup for s390
[S390] cleanup ftrace backend functions
[S390] ptrace cleanup
[S390] smp/idle: call init_idle() before starting a new cpu
[S390] smp: delay idle task creation
[S390] dasd: Correct retry counter for terminated I/O.
[S390] dasd: Add support for raw ECKD access.
[S390] dasd: Prevent deadlock during suspend/resume.
[S390] dasd: Improve handling of stolen DASD reservation
[S390] dasd: do path verification for paths added at runtime
[S390] dasd: add High Performance FICON multitrack support
[S390] cio: reduce memory consumption of itcw structures
[S390] nmi: enable machine checks early
[S390] qeth: buffer count imbalance
...
Linus Torvalds [Fri, 7 Jan 2011 22:50:14 +0000 (14:50 -0800)]
Merge branch 'rmobile-latest' of git://git./linux/kernel/git/lethal/sh-2.6
* 'rmobile-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (67 commits)
ARM: mach-shmobile: update for SMP changes.
ARM: mach-shmobile: update for GIC changes.
ARM: mach-shmobile: Fix up clkdev fallout for SH73A0.
dma: shdma: don't register the global die notifier multiple times
ARM: mach-shmobile: Rely on run-time IRQ handlers
ARM: mach-shmobile: Run-time IRQ handler for GIC
ARM: mach-shmobile: Run-time IRQ handler for INTCA
ARM: mach-shmobile: Enable CONFIG_MULTI_IRQ_HANDLER
ARM: mach-shmobile: Use shared GIC entry macros
ARM: mach-shmobile: mackerel: Add zboot support
ARM: mach-shmobile: mackerel: Add HDMI sound support
ARM: mach-shmobile: mackerel: add HDMI video support
ARM: mach-shmobile: ap4evb: fixup clk_put timing of fsib_clk
ARM: mach-shmobile: sh73a0: fix div4 table
ARM: mach-shmobile: ap4/mackerel: modify wrong comment out of USB
ARM: mach-shmobile: Mackerel VGA camera support
mmc: sh_mmcif: make DMA support by the driver unconditional
ARM: mach-shmobile: Add eMMC support through MMCIF on AG5EVM
ARM: mach-shmobile: Use pullups for AG5EVM KEYSC pins
ARM: mach-shmobile: sh73a0 GPIO pullup improvement
...
Linus Torvalds [Fri, 7 Jan 2011 22:45:47 +0000 (14:45 -0800)]
Merge branch 'for-linus' of git://git./linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (58 commits)
Input: wacom_w8001 - support pen or touch only devices
Input: wacom_w8001 - use __set_bit to set keybits
Input: bu21013_ts - fix misuse of logical operation in place of bitop
Input: i8042 - add Acer Aspire 5100 to the Dritek list
Input: wacom - add support for digitizer in Lenovo W700
Input: psmouse - disable the synaptics extension on OLPC machines
Input: psmouse - fix up Synaptics comment
Input: synaptics - ignore bogus mt packet
Input: synaptics - add multi-finger and semi-mt support
Input: synaptics - report clickpad property
input: mt: Document interface updates
Input: fix double equality sign in uevent
Input: introduce device properties
hid: egalax: Add support for Wetab (726b)
Input: include MT library as source for kerneldoc
MAINTAINERS: Update input-mt entry
hid: egalax: Add support for Samsung NB30 netbook
hid: egalax: Document the new devices in Kconfig
hid: egalax: Add support for Wetab
hid: egalax: Convert to MT slots
...
Fixed up trivial conflict in drivers/input/keyboard/Kconfig
Linus Torvalds [Fri, 7 Jan 2011 22:39:20 +0000 (14:39 -0800)]
Merge branch 'tty-next' of git://git./linux/kernel/git/gregkh/tty-2.6
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
serial: apbuart: Fixup apbuart_console_init()
TTY: Add tty ioctl to figure device node of the system console.
tty: add 'active' sysfs attribute to tty0 and console device
drivers: serial: apbuart: Handle OF failures gracefully
Serial: Avoid unbalanced IRQ wake disable during resume
tty: fix typos/errors in tty_driver.h comments
pch_uart : fix warnings for 64bit compile
8250: fix uninitialized FIFOs
ip2: fix compiler warning on ip2main_pci_tbl
specialix: fix compiler warning on specialix_pci_tbl
rocket: fix compiler warning on rocket_pci_ids
8250: add a UPIO_DWAPB32 for 32 bit accesses
8250: use container_of() instead of casting
serial: omap-serial: Add support for kernel debugger
serial: fix pch_uart kconfig & build
drivers: char: hvc: add arm JTAG DCC console support
RS485 documentation: add 16C950 UART description
serial: ifx6x60: fix memory leak
serial: ifx6x60: free IRQ on error
Serial: EG20T: add PCH_UART driver
...
Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).
Linus Torvalds [Fri, 7 Jan 2011 21:16:28 +0000 (13:16 -0800)]
Merge branch 'usb-next' of git://git./linux/kernel/git/gregkh/usb-2.6
* 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (144 commits)
USB: add support for Dream Cheeky DL100B Webmail Notifier (1d34:0004)
USB: serial: ftdi_sio: add support for TIOCSERGETLSR
USB: ehci-mxc: Setup portsc register prior to accessing OTG viewport
USB: atmel_usba_udc: fix freeing irq in usba_udc_remove()
usb: ehci-omap: fix tll channel enable mask
usb: ohci-omap3: fix trivial typo
USB: gadget: ci13xxx: don't assume that PAGE_SIZE is 4096
USB: gadget: ci13xxx: fix complete() callback for no_interrupt rq's
USB: gadget: update ci13xxx to work with g_ether
USB: gadgets: ci13xxx: fix probing of compiled-in gadget drivers
Revert "USB: musb: pm: don't rely fully on clock support"
Revert "USB: musb: blackfin: pm: make it work"
USB: uas: Use GFP_NOIO instead of GFP_KERNEL in I/O submission path
USB: uas: Ensure we only bind to a UAS interface
USB: uas: Rename sense pipe and sense urb to status pipe and status urb
USB: uas: Use kzalloc instead of kmalloc
USB: uas: Fix up the Sense IU
usb: musb: core: kill unneeded #include's
DA8xx: assign name to MUSB IRQ resource
usb: gadget: g_ncm added
...
Manually fix up trivial conflicts in USB Kconfig changes in:
arch/arm/mach-omap2/Kconfig
arch/sh/Kconfig
drivers/usb/Kconfig
drivers/usb/host/ehci-hcd.c
and annoying chip clock data conflicts in:
arch/arm/mach-omap2/clock3xxx_data.c
arch/arm/mach-omap2/clock44xx_data.c
Linus Torvalds [Fri, 7 Jan 2011 20:47:02 +0000 (12:47 -0800)]
Merge git://git./linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (147 commits)
[SCSI] arcmsr: fix write to device check
[SCSI] lpfc: lower stack use in lpfc_fc_frame_check
[SCSI] eliminate an unnecessary local variable from scsi_remove_target()
[SCSI] libiscsi: use bh locking instead of irq with session lock
[SCSI] libiscsi: do not take host lock in queuecommand
[SCSI] be2iscsi: fix null ptr when accessing task hdr
[SCSI] be2iscsi: fix gfp use in alloc_pdu
[SCSI] libiscsi: add more informative failure message during iscsi scsi eh
[SCSI] gdth: Add missing call to gdth_ioctl_free
[SCSI] bfa: remove unused defintions and misc cleanups
[SCSI] bfa: remove inactive functions
[SCSI] bfa: replace bfa_assert with WARN_ON
[SCSI] qla2xxx: Use sg_next to fetch next sg element while walking sg list.
[SCSI] qla2xxx: Fix to avoid recursive lock failure during BSG timeout.
[SCSI] qla2xxx: Remove code to not reset ISP82xx on failure.
[SCSI] qla2xxx: Display mailbox register 4 during 8012 AEN for ISP82XX parts.
[SCSI] qla2xxx: Don't perform a BIG_HAMMER if Get-ID (0x20) mailbox command fails on CNAs.
[SCSI] qla2xxx: Remove redundant module parameter permission bits
[SCSI] qla2xxx: Add sysfs node for displaying board temperature.
[SCSI] qla2xxx: Code cleanup to remove unwanted comments and code.
...
Dan Carpenter [Fri, 7 Jan 2011 19:47:37 +0000 (20:47 +0100)]
input/tc3589x: fix compile error
There was a semi-colon missing and it broke the compile.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Fri, 7 Jan 2011 16:56:33 +0000 (08:56 -0800)]
Merge branch 'vfs-scale-working' of git://git./linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
fs: scale mntget/mntput
fs: rename vfsmount counter helpers
fs: implement faster dentry memcmp
fs: prefetch inode data in dcache lookup
fs: improve scalability of pseudo filesystems
fs: dcache per-inode inode alias locking
fs: dcache per-bucket dcache hash locking
bit_spinlock: add required includes
kernel: add bl_list
xfs: provide simple rcu-walk ACL implementation
btrfs: provide simple rcu-walk ACL implementation
ext2,3,4: provide simple rcu-walk ACL implementation
fs: provide simple rcu-walk generic_check_acl implementation
fs: provide rcu-walk aware permission i_ops
fs: rcu-walk aware d_revalidate method
fs: cache optimise dentry and inode for rcu-walk
fs: dcache reduce branches in lookup path
fs: dcache remove d_mounted
fs: fs_struct use seqlock
fs: rcu-walk for path lookup
...
Borislav Petkov [Fri, 26 Nov 2010 18:24:44 +0000 (19:24 +0100)]
amd64_edac: Disable DRAM ECC injection on K8
K8 does not allow for an atomic RMW to a cacheline as F10h does so
disable the error injection interface for it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 24 Nov 2010 18:52:09 +0000 (19:52 +0100)]
EDAC: Fixup scrubrate manipulation
Make the ->{get|set}_sdram_scrub_rate return the actual scrub rate
bandwidth it succeeded setting and remove superfluous arg pointer used
for that. A negative value returned still means that an error occurred
while setting the scrubrate. Document this for future reference.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 15 Oct 2010 17:25:38 +0000 (19:25 +0200)]
amd64_edac: Remove two-stage initialization
Now that all prerequisites are in place, drop the two-stage driver
instances initialization in favor of the following simple init sequence:
1. Probe PCI device: we only test ECC capabilities here and if none exit
early.
2. If the hw supports ECC and it is/can be enabled, we init the per-node
instance.
Remove "amd64_" prefix from static functions touched, while at it.
There actually should be no visible functional change resulting from
this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 15 Oct 2010 15:44:04 +0000 (17:44 +0200)]
amd64_edac: Check ECC capabilities initially
Rework the code to check the hardware ECC capabilities at PCI probing
time. We do all further initialization only if we actually can/have ECC
enabled.
While at it:
0. Fix function naming.
1. Simplify/clarify debug output.
2. Remove amd64_ prefix from the static functions
3. Reorganize code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Thu, 14 Oct 2010 14:01:30 +0000 (16:01 +0200)]
amd64_edac: Carve out ECC-related hw settings
This is in preparation for the init path reorganization where we want
only to
1) test whether a particular node supports ECC
2) can it be enabled
and only then do the necessary allocation/initialization. For that,
we need to decouple the ECC settings of the node from the instance's
descriptor.
The should be no functional change introduced by this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Thu, 14 Oct 2010 12:37:13 +0000 (14:37 +0200)]
amd64_edac: Remove PCI ECS enabling functions
PCI ECS is being enabled by default since 2.6.26 on AMD so this code is
just superfluous now, remove it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 13 Oct 2010 20:12:15 +0000 (22:12 +0200)]
amd64_edac: Remove explicit Kconfig PCI dependency
AMD_NB pulls in the dependency on PCI. Clarify/fix help text while at it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 13 Oct 2010 14:11:59 +0000 (16:11 +0200)]
amd64_edac: Allocate driver instances dynamically
Remove static allocation in favor of dynamically allocating space for as
many driver instances as northbridges present on the system.
There should be no functional change resulting from this patch.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Thu, 7 Oct 2010 16:29:15 +0000 (18:29 +0200)]
amd64_edac: Rework printk macros
Add a macro per printk level, shorten up error messages. Add relevant
information to KERN_INFO level. No functional change.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 18:11:07 +0000 (20:11 +0200)]
amd64_edac: Rename CPU PCI devices
Rename variables representing PCI devices to their BKDG names for faster
search and shorter, clearer code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 17:35:38 +0000 (19:35 +0200)]
amd64_edac: Concentrate per-family init even more
Move the remaining per-family init code into the proper place and
simplify the rest of the initialization. Reorganize error handling in
amd64_init_one_instance().
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 17:27:58 +0000 (19:27 +0200)]
amd64_edac: Cleanup the CPU PCI device reservation
Shorten code and clarify comments, return proper -E* values on error.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 17:20:05 +0000 (19:20 +0200)]
amd64_edac: Simplify CPU family detection
Concentrate CPU family detection in the per-family init function.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 16:38:19 +0000 (18:38 +0200)]
amd64_edac: Add per-family init function
Run a per-family init function which does all the settings based on
the family this driver instance is running on. Move the scrubrate
calculation in it and simplify code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 17:44:53 +0000 (19:44 +0200)]
amd64_edac: Use cached extended CPU model
... instead of computing it needlessly again.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 1 Oct 2010 16:19:06 +0000 (18:19 +0200)]
amd64_edac: Remove F11h support
F11h doesn't support DRAM ECC so whack it away.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Nick Piggin [Fri, 7 Jan 2011 06:50:11 +0000 (17:50 +1100)]
fs: scale mntget/mntput
The problem that this patch aims to fix is vfsmount refcounting scalability.
We need to take a reference on the vfsmount for every successful path lookup,
which often go to the same mount point.
The fundamental difficulty is that a "simple" reference count can never be made
scalable, because any time a reference is dropped, we must check whether that
was the last reference. To do that requires communication with all other CPUs
that may have taken a reference count.
We can make refcounts more scalable in a couple of ways, involving keeping
distributed counters, and checking for the global-zero condition less
frequently.
- check the global sum once every interval (this will delay zero detection
for some interval, so it's probably a showstopper for vfsmounts).
- keep a local count and only taking the global sum when local reaches 0 (this
is difficult for vfsmounts, because we can't hold preempt off for the life of
a reference, so a counter would need to be per-thread or tied strongly to a
particular CPU which requires more locking).
- keep a local difference of increments and decrements, which allows us to sum
the total difference and hence find the refcount when summing all CPUs. Then,
keep a single integer "long" refcount for slow and long lasting references,
and only take the global sum of local counters when the long refcount is 0.
This last scheme is what I implemented here. Attached mounts and process root
and working directory references are "long" references, and everything else is
a short reference.
This allows scalable vfsmount references during path walking over mounted
subtrees and unattached (lazy umounted) mounts with processes still running
in them.
This results in one fewer atomic op in the fastpath: mntget is now just a
per-CPU inc, rather than an atomic inc; and mntput just requires a spinlock
and non-atomic decrement in the common case. However code is otherwise bigger
and heavier, so single threaded performance is basically a wash.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:10 +0000 (17:50 +1100)]
fs: rename vfsmount counter helpers
Suggested by Andreas, mnt_ prefix is clearer namespace, follows kernel
conventions better, and is easier for tab complete. I introduced these
names so I'll admit they were not good choices.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:09 +0000 (17:50 +1100)]
fs: implement faster dentry memcmp
The standard memcmp function on a Westmere system shows up hot in
profiles in the `git diff` workload (both parallel and single threaded),
and it is likely due to the costs associated with trapping into
microcode, and little opportunity to improve memory access (dentry
name is not likely to take up more than a cacheline).
So replace it with an open-coded byte comparison. This increases code
size by 8 bytes in the critical __d_lookup_rcu function, but the
speedup is huge, averaging 10 runs of each:
git diff st user sys elapsed CPU
before 1.15 2.57 3.82 97.1
after 1.14 2.35 3.61 96.8
git diff mt user sys elapsed CPU
before 1.27 3.85 1.46 349
after 1.26 3.54 1.43 333
Elapsed time for single threaded git diff at 95.0% confidence:
-0.21 +/- 0.01
-5.45% +/- 0.24%
It's -0.66% +/- 0.06% elapsed time on my Opteron, so rep cmp costs on the
fam10h seem to be relatively smaller, but there is still a win.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:08 +0000 (17:50 +1100)]
fs: prefetch inode data in dcache lookup
This makes single threaded git diff -1.25% +/- 0.05% elapsed time on my
2s12c24t Westmere system, and -0.86% +/- 0.05% on my 2s8c Barcelona, by
prefetching the important first cacheline of the inode in while we do the
actual name compare and other operations on the dentry.
There was no measurable slowdown in the single file stat case, or the creat
case (where negative dentries would be common).
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:07 +0000 (17:50 +1100)]
fs: improve scalability of pseudo filesystems
Regardless of how much we possibly try to scale dcache, there is likely
always going to be some fundamental contention when adding or removing children
under the same parent. Pseudo filesystems do not seem need to have connected
dentries because by definition they are disconnected.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:06 +0000 (17:50 +1100)]
fs: dcache per-inode inode alias locking
dcache_inode_lock can be replaced with per-inode locking. Use existing
inode->i_lock for this. This is slightly non-trivial because we sometimes
need to find the inode from the dentry, which requires d_inode to be
stabilised (either with refcount or d_lock).
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:05 +0000 (17:50 +1100)]
fs: dcache per-bucket dcache hash locking
We can turn the dcache hash locking from a global dcache_hash_lock into
per-bucket locking.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:04 +0000 (17:50 +1100)]
bit_spinlock: add required includes
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:03 +0000 (17:50 +1100)]
kernel: add bl_list
Introduce a type of hlist that can support the use of the lowest bit in the
hlist_head. This will be subsequently used to implement per-bucket bit spinlock
for inode and dentry hashes, and may be useful in other cases such as network
hashes.
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:02 +0000 (17:50 +1100)]
xfs: provide simple rcu-walk ACL implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:01 +0000 (17:50 +1100)]
btrfs: provide simple rcu-walk ACL implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:50:00 +0000 (17:50 +1100)]
ext2,3,4: provide simple rcu-walk ACL implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:59 +0000 (17:49 +1100)]
fs: provide simple rcu-walk generic_check_acl implementation
This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.
This could easily be extended to put acls under RCU and check them
under seqlock, if need be. But this implementation is enough to show
the rcu-walk aware permissions code for path lookups is working, and
will handle cases where there are no ACLs or ACLs in just the final
element.
This patch implicity converts tmpfs to rcu-aware permission check.
Subsequent patches onvert ext*, xfs, and, btrfs. Each of these uses
acl/permission code in a different way, so convert them all to provide
templates and proof of concept.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:58 +0000 (17:49 +1100)]
fs: provide rcu-walk aware permission i_ops
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:57 +0000 (17:49 +1100)]
fs: rcu-walk aware d_revalidate method
Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:56 +0000 (17:49 +1100)]
fs: cache optimise dentry and inode for rcu-walk
Put dentry and inode fields into top of data structure. This allows RCU path
traversal to perform an RCU dentry lookup in a path walk by touching only the
first 56 bytes of the dentry.
We also fit in 8 bytes of inline name in the first 64 bytes, so for short
names, only 64 bytes needs to be touched to perform the lookup. We should
get rid of the hash->prev pointer from the first 64 bytes, and fit 16 bytes
of name in there, which will take care of 81% rather than 32% of the kernel
tree.
inode is also rearranged so that RCU lookup will only touch a single cacheline
in the inode, plus one in the i_ops structure.
This is important for directory component lookups in RCU path walking. In the
kernel source, directory names average is around 6 chars, so this works.
When we reach the last element of the lookup, we need to lock it and take its
refcount which requires another cacheline access.
Align dentry and inode operations structs, so members will be at predictable
offsets and we can group common operations into head of structure.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:55 +0000 (17:49 +1100)]
fs: dcache reduce branches in lookup path
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:54 +0000 (17:49 +1100)]
fs: dcache remove d_mounted
Rather than keep a d_mounted count in the dentry, set a dentry flag instead.
The flag can be cleared by checking the hash table to see if there are any
mounts left, which is not time critical because it is performed at detach time.
The mounted state of a dentry is only used to speculatively take a look in the
mount hash table if it is set -- before following the mount, vfsmount lock is
taken and mount re-checked without races.
This saves 4 bytes on 32-bit, nothing on 64-bit but it does provide a hole I
might use later (and some configs have larger than 32-bit spinlocks which might
make use of the hole).
Autofs4 conversion and changelog by Ian Kent <raven@themaw.net>:
In autofs4, when expring direct (or offset) mounts we need to ensure that we
block user path walks into the autofs mount, which is covered by another mount.
To do this we clear the mounted status so that follows stop before walking into
the mount and are essentially blocked until the expire is completed. The
automount daemon still finds the correct dentry for the umount due to the
follow mount logic in fs/autofs4/root.c:autofs4_follow_link(), which is set as
an inode operation for direct and offset mounts only and is called following
the lookup that stopped at the covered mount.
At the end of the expire the covering mount probably has gone away so the
mounted status need not be restored. But we need to check this and only restore
the mounted status if the expire failed.
XXX: autofs may not work right if we have other mounts go over the top of it?
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:53 +0000 (17:49 +1100)]
fs: fs_struct use seqlock
Use a seqlock in the fs_struct to enable us to take an atomic copy of the
complete cwd and root paths. Use this in the RCU lookup path to avoid a
thread-shared spinlock in RCU lookup operations.
Multi-threaded apps may now perform path lookups with scalability matching
multi-process apps. Operations such as stat(2) become very scalable for
multi-threaded workload.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:52 +0000 (17:49 +1100)]
fs: rcu-walk for path lookup
Perform common cases of path lookups without any stores or locking in the
ancestor dentry elements. This is called rcu-walk, as opposed to the current
algorithm which is a refcount based walk, or ref-walk.
This results in far fewer atomic operations on every path element,
significantly improving path lookup performance. It also avoids cacheline
bouncing on common dentries, significantly improving scalability.
The overall design is like this:
* LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk.
* Take the RCU lock for the entire path walk, starting with the acquiring
of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are
not required for dentry persistence.
* synchronize_rcu is called when unregistering a filesystem, so we can
access d_ops and i_ops during rcu-walk.
* Similarly take the vfsmount lock for the entire path walk. So now mnt
refcounts are not required for persistence. Also we are free to perform mount
lookups, and to assume dentry mount points and mount roots are stable up and
down the path.
* Have a per-dentry seqlock to protect the dentry name, parent, and inode,
so we can load this tuple atomically, and also check whether any of its
members have changed.
* Dentry lookups (based on parent, candidate string tuple) recheck the parent
sequence after the child is found in case anything changed in the parent
during the path walk.
* inode is also RCU protected so we can load d_inode and use the inode for
limited things.
* i_mode, i_uid, i_gid can be tested for exec permissions during path walk.
* i_op can be loaded.
When we reach the destination dentry, we lock it, recheck lookup sequence,
and increment its refcount and mountpoint refcount. RCU and vfsmount locks
are dropped. This is termed "dropping rcu-walk". If the dentry refcount does
not match, we can not drop rcu-walk gracefully at the current point in the
lokup, so instead return -ECHILD (for want of a better errno). This signals the
path walking code to re-do the entire lookup with a ref-walk.
Aside from the final dentry, there are other situations that may be encounted
where we cannot continue rcu-walk. In that case, we drop rcu-walk (ie. take
a reference on the last good dentry) and continue with a ref-walk. Again, if
we can drop rcu-walk gracefully, we return -ECHILD and do the whole lookup
using ref-walk. But it is very important that we can continue with ref-walk
for most cases, particularly to avoid the overhead of double lookups, and to
gain the scalability advantages on common path elements (like cwd and root).
The cases where rcu-walk cannot continue are:
* NULL dentry (ie. any uncached path element)
* parent with d_inode->i_op->permission or ACLs
* dentries with d_revalidate
* Following links
In future patches, permission checks and d_revalidate become rcu-walk aware. It
may be possible eventually to make following links rcu-walk aware.
Uncached path elements will always require dropping to ref-walk mode, at the
very least because i_mutex needs to be grabbed, and objects allocated.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:51 +0000 (17:49 +1100)]
kernel: optimise seqlock
Add branch annotations for seqlock read fastpath, and introduce
__read_seqcount_begin and __read_seqcount_end functions, that can avoid the
smp_rmb() if used carefully. These will be used by store-free path walking
algorithm performance is critical and seqlocks are in use.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:50 +0000 (17:49 +1100)]
fs: avoid inode RCU freeing for pseudo fs
Pseudo filesystems that don't put inode on RCU list or reachable by
rcu-walk dentries do not need to RCU free their inodes.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:49 +0000 (17:49 +1100)]
fs: icache RCU free inodes
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:48 +0000 (17:49 +1100)]
fs: consolidate dentry kill sequence
The tricky locking for disposing of a dentry is duplicated 3 times in the
dcache (dput, pruning a dentry from the LRU, and pruning its ancestors).
Consolidate them all into a single function dentry_kill.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:47 +0000 (17:49 +1100)]
fs: use RCU in shrink_dentry_list to reduce lock nesting
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:46 +0000 (17:49 +1100)]
fs: reduce dcache_inode_lock width in lru scanning
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:45 +0000 (17:49 +1100)]
fs: dcache reduce prune_one_dentry locking
prune_one_dentry can avoid quite a bit of locking in the common case where
ancestors have an elevated refcount. Alternatively, we could have gone the
other way and made fewer trylocks in the case where d_count goes to zero, but
is probably less common.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:44 +0000 (17:49 +1100)]
fs: dcache reduce d_parent locking
Use RCU to simplify locking in dget_parent.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:43 +0000 (17:49 +1100)]
fs: dcache rationalise dget variants
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:42 +0000 (17:49 +1100)]
fs: dcache reduce dcache_inode_lock
dcache_inode_lock can be avoided in d_delete() and d_materialise_unique()
in cases where it is not required.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:41 +0000 (17:49 +1100)]
fs: dcache reduce locking in d_alloc
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:40 +0000 (17:49 +1100)]
fs: dcache reduce dput locking
It is possible to run dput without taking data structure locks up-front. In
many cases where we don't kill the dentry anyway, these locks are not required.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:39 +0000 (17:49 +1100)]
fs: dcache avoid starvation in dcache multi-step operations
Long lived dcache "multi-step" operations which retry on rename seq can
be starved with a lot of rename activity. If they fail after the 1st pass,
take the rename_lock for writing to avoid further starvation.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:38 +0000 (17:49 +1100)]
fs: dcache remove dcache_lock
dcache_lock no longer protects anything. remove it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:37 +0000 (17:49 +1100)]
fs: Use rename lock and RCU for multi-step operations
The remaining usages for dcache_lock is to allow atomic, multi-step read-side
operations over the directory tree by excluding modifications to the tree.
Also, to walk in the leaf->root direction in the tree where we don't have
a natural d_lock ordering.
This could be accomplished by taking every d_lock, but this would mean a
huge number of locks and actually gets very tricky.
Solve this instead by using the rename seqlock for multi-step read-side
operations, retry in case of a rename so we don't walk up the wrong parent.
Concurrent dentry insertions are not serialised against. Concurrent deletes
are tricky when walking up the directory: our parent might have been deleted
when dropping locks so also need to check and retry for that.
We can also use the rename lock in cases where livelock is a worry (and it
is introduced in subsequent patch).
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:36 +0000 (17:49 +1100)]
fs: increase d_name lock coverage
Cover d_name with d_lock in more cases, where there may be concurrent
modification to it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:35 +0000 (17:49 +1100)]
fs: scale inode alias list
Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:34 +0000 (17:49 +1100)]
fs: dcache scale subdirs
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).
Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:33 +0000 (17:49 +1100)]
fs: dcache scale d_unhashed
Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:32 +0000 (17:49 +1100)]
fs: dcache scale dentry refcount
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:31 +0000 (17:49 +1100)]
fs: dcache scale lru
Add a new lock, dcache_lru_lock, to protect the dcache LRU list from concurrent
modification. d_lru is also protected by d_lock, which allows LRU lists to be
accessed without the lru lock, using RCU in future patches.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:30 +0000 (17:49 +1100)]
fs: dcache scale hash
Add a new lock, dcache_hash_lock, to protect the dcache hash table from
concurrent modification. d_hash is also protected by d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:29 +0000 (17:49 +1100)]
hostfs: simplify locking
Remove dcache_lock locking from hostfs filesystem, and move it into dcache
helpers. All that is required is a coherent path name. Protection from
concurrent modification of the namespace after path name generation is not
provided in current code, because dcache_lock is dropped before the path is
used.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:28 +0000 (17:49 +1100)]
fs: change d_hash for rcu-walk
Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:27 +0000 (17:49 +1100)]
fs: change d_compare for rcu-walk
Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:26 +0000 (17:49 +1100)]
fs: name case update method
smpfs and ncpfs want to update a live dentry name in-place. Rather than
have them open code the locking, provide a documented dcache API.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:25 +0000 (17:49 +1100)]
jfs: dont overwrite dentry name in d_revalidate
Use vfat's method for dealing with negative dentries to preserve case,
rather than overwrite dentry name in d_revalidate, which is a bit ugly
and also gets in the way of doing lock-free path walking.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:24 +0000 (17:49 +1100)]
cifs: dont overwrite dentry name in d_revalidate
Use vfat's method for dealing with negative dentries to preserve case,
rather than overwrite dentry name in d_revalidate, which is a bit ugly
and also gets in the way of doing lock-free path walking.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:23 +0000 (17:49 +1100)]
fs: change d_delete semantics
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.
This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:22 +0000 (17:49 +1100)]
fs: dcache documentation cleanup
Remove redundant (and incorrect, since dcache RCU lookup) dentry locking
documentation and point to the canonical document.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:21 +0000 (17:49 +1100)]
config fs: avoid switching ->d_op on live dentry
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix configfs so as not to do this.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:20 +0000 (17:49 +1100)]
cgroup fs: avoid switching ->d_op on live dentry
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix cgroupfs so as not to do this.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:19 +0000 (17:49 +1100)]
fs: use fast counters for vfs caches
percpu_counter library generates quite nasty code, so unless you need
to dynamically allocate counters or take fast approximate value, a
simple per cpu set of counters is much better.
The percpu_counter can never be made to work as well, because it has an
indirection from pointer to percpu memory, and it can't use direct
this_cpu_inc interfaces because it doesn't use static PER_CPU data, so
code will always be worse.
In the fastpath, it is the difference between this:
incl %gs:nr_dentry # nr_dentry
and this:
movl percpu_counter_batch(%rip), %edx # percpu_counter_batch,
movl $1, %esi #,
movq $nr_dentry, %rdi #,
call __percpu_counter_add # (plus I clobber registers)
__percpu_counter_add:
pushq %rbp #
movq %rsp, %rbp #,
subq $32, %rsp #,
movq %rbx, -24(%rbp) #,
movq %r12, -16(%rbp) #,
movq %r13, -8(%rbp) #,
movq %rdi, %rbx # fbc, fbc
#APP
# 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1
movq %gs:kernel_stack,%rax #, pfo_ret__
# 0 "" 2
#NO_APP
incl -8124(%rax) # <variable>.preempt_count
movq 32(%rdi), %r12 # <variable>.counters, tcp_ptr__
#APP
# 78 "lib/percpu_counter.c" 1
add %gs:this_cpu_off, %r12 # this_cpu_off, tcp_ptr__
# 0 "" 2
#NO_APP
movslq (%r12),%r13 #* tcp_ptr__, tmp73
movslq %edx,%rax # batch, batch
addq %rsi, %r13 # amount, count
cmpq %rax, %r13 # batch, count
jge .L27 #,
negl %edx # tmp76
movslq %edx,%rdx # tmp76, tmp77
cmpq %rdx, %r13 # tmp77, count
jg .L28 #,
.L27:
movq %rbx, %rdi # fbc,
call _raw_spin_lock #
addq %r13, 8(%rbx) # count, <variable>.count
movq %rbx, %rdi # fbc,
movl $0, (%r12) #,* tcp_ptr__
call _raw_spin_unlock #
.L29:
#APP
# 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1
movq %gs:kernel_stack,%rax #, pfo_ret__
# 0 "" 2
#NO_APP
decl -8124(%rax) # <variable>.preempt_count
movq -8136(%rax), %rax #, D.14625
testb $8, %al #, D.14625
jne .L32 #,
.L31:
movq -24(%rbp), %rbx #,
movq -16(%rbp), %r12 #,
movq -8(%rbp), %r13 #,
leave
ret
.p2align 4,,10
.p2align 3
.L28:
movl %r13d, (%r12) # count,*
jmp .L29 #
.L32:
call preempt_schedule #
.p2align 4,,6
jmp .L31 #
.size __percpu_counter_add, .-__percpu_counter_add
.p2align 4,,15
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:18 +0000 (17:49 +1100)]
vfs: revert per-cpu nr_unused counters for dentry and inodes
The nr_unused counters count the number of objects on an LRU, and as such they
are synchronized with LRU object insertion and removal and scanning, and
protected under the LRU lock.
Making it per-cpu does not actually get any concurrency improvements because of
this lock, and summing the counter is much slower, and
incrementing/decrementing it costs more code size and is slower too.
These counters should stay per-LRU, which currently means global.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:17 +0000 (17:49 +1100)]
kernel: kmem_ptr_validate considered harmful
This is a nasty and error prone API. It is no longer used, remove it.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Nick Piggin [Fri, 7 Jan 2011 06:49:16 +0000 (17:49 +1100)]
fs: d_validate fixes
d_validate has been broken for a long time.
kmem_ptr_validate does not guarantee that a pointer can be dereferenced
if it can go away at any time. Even rcu_read_lock doesn't help, because
the pointer might be queued in RCU callbacks but not executed yet.
So the parent cannot be checked, nor the name hashed. The dentry pointer
can not be touched until it can be verified under lock. Hashing simply
cannot be used.
Instead, verify the parent/child relationship by traversing parent's
d_child list. It's slow, but only ncpfs and the destaged smbfs care
about it, at this point.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Dmitry Torokhov [Fri, 7 Jan 2011 06:34:59 +0000 (22:34 -0800)]
Merge branch 'next' into for-linus
Conflicts:
include/linux/input.h
Linus Torvalds [Fri, 7 Jan 2011 03:13:58 +0000 (19:13 -0800)]
Merge branch 'omap-for-linus' of git://git./linux/kernel/git/tmlind/linux-omap-2.6
* 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (243 commits)
omap2: Make OMAP2PLUS select OMAP_DM_TIMER
OMAP4: hwmod data: Fix alignment and end of line in structurefields
OMAP4: hwmod data: Move the DMA structures
OMAP4: hwmod data: Move the smartreflex structures
OMAP4: hwmod data: Fix missing SIDLE_SMART_WKUP in smartreflexsysc
arm: omap: tusb6010: add name for MUSB IRQ
arm: omap: craneboard: Add USB EHCI support
omap2+: Initialize serial port for dynamic remuxing for n8x0
omap2+: Add struct omap_board_data and use it for platform level serial init
omap2+: Allow hwmod state changes to mux pads based on the state changes
omap2+: Add support for hwmod specific muxing of devices
omap2+: Add omap_mux_get_by_name
OMAP2: PM: fix compile error when !CONFIG_SUSPEND
MAINTAINERS: OMAP: hwmod: update hwmod code, data maintainership
OMAP4: Smartreflex framework extensions
OMAP4: hwmod: Add inital data for smartreflex modules.
OMAP4: PM: Program correct init voltages for scalable VDDs
OMAP4: Adding voltage driver support
OMAP4: Register voltage PMIC parameters with the voltage layer
OMAP3: PM: Program correct init voltages for VDD1 and VDD2
...
Fix up trivial conflict in arch/arm/plat-omap/Kconfig
Paul Mundt [Fri, 7 Jan 2011 03:03:22 +0000 (12:03 +0900)]
ARM: mach-shmobile: update for SMP changes.
There have likewise been some API updates, so we refactor to use the
consolidated smp_prepare_cpus().
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Paul Mundt [Fri, 7 Jan 2011 03:02:11 +0000 (12:02 +0900)]
ARM: mach-shmobile: update for GIC changes.
This fixes up the SMP support to use the refactored GIC APIs.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Paul Mundt [Fri, 7 Jan 2011 02:49:49 +0000 (11:49 +0900)]
ARM: mach-shmobile: Fix up clkdev fallout for SH73A0.
Use the new linux/clkdev.h to get it building again.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Linus Torvalds [Fri, 7 Jan 2011 02:32:12 +0000 (18:32 -0800)]
Merge branch 'v4l_for_linus' of git://git./linux/kernel/git/mchehab/linux-2.6
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (255 commits)
[media] radio-aimslab.c: Fix gcc 4.5+ bug
[media] cx25821: Fix compilation breakage due to BKL dependency
[media] v4l2-compat-ioctl32: fix compile warning
[media] zoran: fix compiler warning
[media] tda18218: fix compile warning
[media] ngene: fix compile warning
[media] DVB: IR support for TechnoTrend CT-3650
[media] cx23885, cimax2.c: Fix case of two CAM insertion irq
[media] ir-nec-decoder: fix repeat key issue
[media] staging: se401 depends on USB
[media] staging: usbvideo/vicam depends on USB
[media] soc_camera: Add the ability to bind regulators to soc_camedra devices
[media] V4L2: Add a v4l2-subdev (soc-camera) driver for OmniVision OV2640 sensor
[media] v4l: soc-camera: switch to .unlocked_ioctl
[media] v4l: ov772x: simplify pointer dereference
[media] ov9640: fix OmniVision OV9640 sensor driver's priv data retrieving
[media] ov9640: use macro to request OmniVision OV9640 sensor private data
[media] ivtv-i2c: Fix two warnings
[media] staging/lirc: Update lirc TODO files
[media] cx88: Remove the obsolete i2c_adapter.id field
...
Paul Mundt [Fri, 7 Jan 2011 02:03:37 +0000 (11:03 +0900)]
Merge branch 'common/dma' into rmobile-latest
Guennadi Liakhovetski [Thu, 6 Jan 2011 17:04:50 +0000 (17:04 +0000)]
dma: shdma: don't register the global die notifier multiple times
A recent patch has added a die notifier to the shdma driver, however,
it registers a static die-notifier object in the probe routine, i.e.,
for each device instance. This is wrong and leads to a system lockup.
This patch moves the die notifier registration to module init and
exit routines respectively.
Reported-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Paul Mundt [Fri, 7 Jan 2011 01:51:35 +0000 (10:51 +0900)]
Merge branch 'rmobile/smp' into rmobile-latest
Conflicts:
arch/arm/Kconfig
arch/arm/mach-shmobile/include/mach/entry-macro-intc.S
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Tue, 28 Dec 2010 08:27:19 +0000 (08:27 +0000)]
ARM: mach-shmobile: Rely on run-time IRQ handlers
Remove now unused IRQ demux code. All R-Mobile and
SH-Mobile processors should register IRQ demux
handlers during run-time.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Tue, 28 Dec 2010 08:27:10 +0000 (08:27 +0000)]
ARM: mach-shmobile: Run-time IRQ handler for GIC
Break-out GIC specific IRQ demux code from the file
entry-macro-intc.S and register during run-time.
Covers sh73a0.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Tue, 28 Dec 2010 08:27:01 +0000 (08:27 +0000)]
ARM: mach-shmobile: Run-time IRQ handler for INTCA
Break-out INTC specific IRQ demux code from the file
entry-macro-intc.S and register during run-time.
Covers sh7367, sh7377 and sh7372.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Tue, 28 Dec 2010 08:26:52 +0000 (08:26 +0000)]
ARM: mach-shmobile: Enable CONFIG_MULTI_IRQ_HANDLER
Always enable MULTI_IRQ_HANDLER on SH-Mobile.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Wed, 22 Dec 2010 12:17:09 +0000 (12:17 +0000)]
ARM: mach-shmobile: Use shared GIC entry macros
Use the GIC demux code in asm/hardware/entry-macro-gic.S
on the R-Mobile / SH-Mobile processors.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Simon Horman [Thu, 9 Dec 2010 00:47:15 +0000 (00:47 +0000)]
ARM: mach-shmobile: mackerel: Add zboot support
When CONFIG_ZBOOT_ROM is selected, the resulting zImage file will be small
boot loader and may be burned to rom or flash.
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Paul Mundt [Fri, 7 Jan 2011 01:29:26 +0000 (10:29 +0900)]
Merge branch 'master' of /linux/kernel/git/torvalds/linux-2.6 into rmobile-latest
Conflicts:
arch/arm/mach-shmobile/Kconfig
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Linus Torvalds [Fri, 7 Jan 2011 00:50:35 +0000 (16:50 -0800)]
Merge branch 'devel' of /home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
Linus Torvalds [Thu, 6 Jan 2011 23:30:54 +0000 (15:30 -0800)]
Merge git://git./linux/kernel/git/davem/sparc-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6: (25 commits)
atyfb: Fix bootup hangs on sparc64.
sparc: update copyright in piggyback.c
sparc: unify strip command in boot/Makefile
sparc: rename piggyback_32 to piggyback
sparc: fix tftpboot.img for sparc64 on little-endian host
sparc: add $BITS to piggyback arguments
sparc: remove obsolete ELF support in piggyback_32.c
sparc: additional comments to piggyback_32.c
sparc: use _start for the start entry (like 64 bit does)
sparc: use trapbase in setup_arch
sparc: refactor piggy_32.c
Added support for ampopts in APBUART driver. Used in AMP systems.
APBUART: added raw AMBA vendor/device number to match against.
SPARC/LEON: avoid AMBAPP name duplicates in openprom fs when REG is missing
SPARC/LEON: added support for selecting Timer Core and Timer within core
LEON: added raw AMBA vendor/device number to find TIMER, IRQCTRL
SPARC/LEON: added support for IRQAMP IRQ Controller
SPARC/LEON: find IRQCTRL and Timer via OF-Tree, instead of hardcoded.
sparc: fix sparse warnings in arch/sparc/prom for 32 bit build
sparc: remove unused prom tree functions
...
Russell King [Thu, 6 Jan 2011 22:33:32 +0000 (22:33 +0000)]
Merge branch 'devel-stable' into devel
Conflicts:
arch/arm/mach-pxa/clock.c
arch/arm/mach-pxa/clock.h