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Jeff Layton [Fri, 7 Jan 2011 16:30:28 +0000 (11:30 -0500)]
cifs: remove unnecessary locking around sequence_number
The server->sequence_number is already protected by the srv_mutex. The
GlobalMid_lock is unneeded here.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Steve French [Sun, 9 Jan 2011 23:26:56 +0000 (23:26 +0000)]
[CIFS] Fix minor merge conflict in fs/cifs/dir.c
Signed-off-by: Steve French <sfrench@us.ibm.com>
Steve French [Sun, 9 Jan 2011 23:18:16 +0000 (23:18 +0000)]
Merge branch 'master' of /linux/kernel/git/torvalds/linux-2.6
Conflicts:
fs/cifs/dir.c
Linus Torvalds [Sat, 8 Jan 2011 01:16:27 +0000 (17:16 -0800)]
Merge branch 'for-next' of git://git./linux/kernel/git/hch/hfsplus
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus:
hfsplus: %L-to-%ll, macro correction, and remove unneeded braces
hfsplus: spaces/indentation clean-up
hfsplus: C99 comments clean-up
hfsplus: over 80 character lines clean-up
hfsplus: fix an artifact in ioctl flag checking
hfsplus: flush disk caches in sync and fsync
hfsplus: optimize fsync
hfsplus: split up inode flags
hfsplus: write up fsync for directories
hfsplus: simplify fsync
hfsplus: avoid useless work in hfsplus_sync_fs
hfsplus: make sure sync writes out all metadata
hfsplus: use raw bio access for partition tables
hfsplus: use raw bio access for the volume headers
hfsplus: always use hfsplus_sync_fs to write the volume header
hfsplus: silence a few debug printks
hfsplus: fix option parsing during remount
Fix up conflicts due to VFS changes in fs/hfsplus/{hfsplus_fs.h,unicode.c}
Linus Torvalds [Sat, 8 Jan 2011 01:08:46 +0000 (17:08 -0800)]
Merge branch 'next-spi' of git://git.secretlab.ca/git/linux-2.6
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6: (77 commits)
spi/omap: Fix DMA API usage in OMAP MCSPI driver
spi/imx: correct the test on platform_get_irq() return value
spi/topcliff: Typo fix threhold to threshold
spi/dw_spi Typo change diable to disable.
spi/fsl_espi: change the read behaviour of the SPIRF
spi/mpc52xx-psc-spi: move probe/remove to proper sections
spi/dw_spi: add DMA support
spi/dw_spi: change to EXPORT_SYMBOL_GPL for exported APIs
spi/dw_spi: Fix too short timeout in spi polling loop
spi/pl022: convert running variable
spi/pl022: convert busy flag to a bool
spi/pl022: pass the returned sglen to the DMA engine
spi/pl022: map the buffers on the DMA engine
spi/topcliff_pch: Fix data transfer issue
spi/imx: remove autodetection
spi/pxa2xx: pass of_node to spi device and set a parent device
spi/pxa2xx: Modify RX-Tresh instead of busy-loop for the remaining RX bytes.
spi/pxa2xx: Add chipselect support for Sodaville
spi/pxa2xx: Consider CE4100's FIFO depth
spi/pxa2xx: Add CE4100 support
...
Linus Torvalds [Sat, 8 Jan 2011 01:02:58 +0000 (17:02 -0800)]
Merge branch 'for-2.6.38' of git://git./linux/kernel/git/tj/percpu
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
Linus Torvalds [Sat, 8 Jan 2011 00:58:04 +0000 (16:58 -0800)]
Merge branch 'for-2.6.38' of git://git./linux/kernel/git/tj/wq
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits)
usb: don't use flush_scheduled_work()
speedtch: don't abuse struct delayed_work
media/video: don't use flush_scheduled_work()
media/video: explicitly flush request_module work
ioc4: use static work_struct for ioc4_load_modules()
init: don't call flush_scheduled_work() from do_initcalls()
s390: don't use flush_scheduled_work()
rtc: don't use flush_scheduled_work()
mmc: update workqueue usages
mfd: update workqueue usages
dvb: don't use flush_scheduled_work()
leds-wm8350: don't use flush_scheduled_work()
mISDN: don't use flush_scheduled_work()
macintosh/ams: don't use flush_scheduled_work()
vmwgfx: don't use flush_scheduled_work()
tpm: don't use flush_scheduled_work()
sonypi: don't use flush_scheduled_work()
hvsi: don't use flush_scheduled_work()
xen: don't use flush_scheduled_work()
gdrom: don't use flush_scheduled_work()
...
Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c
as per Tejun.
Linus Torvalds [Fri, 7 Jan 2011 22:55:48 +0000 (14:55 -0800)]
Merge branch 'sched-fixes-for-linus' of git://git./linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Constify function scope static struct sched_param usage
sched: Fix strncmp operation
sched: Move sched_autogroup_exit() to free_signal_struct()
sched: Fix struct autogroup memory leak
sched: Mark autogroup_init() __init
sched: Consolidate the name of root_task_group and init_task_group
Linus Torvalds [Fri, 7 Jan 2011 22:55:31 +0000 (14:55 -0800)]
Merge branch 'x86-apic-cleanups-for-linus' of git://git./linux/kernel/git/tip/linux-2.6-tip
* 'x86-apic-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: apic: Cleanup and simplify setup_local_APIC()
x86: Further simplify mp_irq info handling
x86: Unify 3 similar ways of saving mp_irqs info
x86, ioapic: Avoid writing io_apic id if already correct
x86, x2apic: Don't map lapic addr for preenabled x2apic systems
x86, sfi: Use register_lapic_address()
x86, apic: Use register_lapic_address() in init_apic_mapping()
x86, apic: Remove early_init_lapic_mapping()
x86, apic: Unify identical register_lapic_address() functions
Linus Torvalds [Fri, 7 Jan 2011 22:54:03 +0000 (14:54 -0800)]
Merge branch 'mce-for-linus' of git://git./linux/kernel/git/bp/bp
* 'mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
EDAC, MCE: Fix NB error formatting
EDAC, MCE: Use BIT_64() to eliminate warnings on 32-bit
EDAC, MCE: Enable MCE decoding on F15h
EDAC, MCE: Allow F15h bank 6 MCE injection
EDAC, MCE: Shorten error report formatting
EDAC, MCE: Overhaul error fields extraction macros
EDAC, MCE: Add F15h FP MCE decoder
EDAC, MCE: Add F15 EX MCE decoder
EDAC, MCE: Add an F15h NB MCE decoder
EDAC, MCE: No F15h LS MCE decoder
EDAC, MCE: Add F15h CU MCE decoder
EDAC, MCE: Add F15h IC MCE decoder
EDAC, MCE: Add F15h DC MCE decoder
EDAC, MCE: Select extended error code mask
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>
Russell King - ARM Linux [Fri, 7 Jan 2011 15:49:20 +0000 (15:49 +0000)]
spi/omap: Fix DMA API usage in OMAP MCSPI driver
Running the latest kernel on the 4430SDP board with DMA API debugging
enabled results in this:
WARNING: at lib/dma-debug.c:803 check_unmap+0x19c/0x6f0()
NULL NULL: DMA-API: device driver tries to free DMA memory it has not allocated
[device address=0x000000008129901a] [size=260 bytes]
Modules linked in:
Backtrace:
[<
c003cbe0>] (dump_backtrace+0x0/0x10c) from [<
c0278da8>] (dump_stack+0x18/0x1c)
r7:
c1839dc0 r6:
c0198578 r5:
c0304b17 r4:
00000323
[<
c0278d90>] (dump_stack+0x0/0x1c) from [<
c005b158>] (warn_slowpath_common+0x58/0x70)
[<
c005b100>] (warn_slowpath_common+0x0/0x70) from [<
c005b214>] (warn_slowpath_fmt+0x38/0x40)
r8:
c1839e40 r7:
00000000 r6:
00000104 r5:
00000000 r4:
8129901a
[<
c005b1dc>] (warn_slowpath_fmt+0x0/0x40) from [<
c0198578>] (check_unmap+0x19c/0x6f0)
r3:
c03110de r2:
c0304e6b
[<
c01983dc>] (check_unmap+0x0/0x6f0) from [<
c0198cd8>] (debug_dma_unmap_page+0x74/0x80)
[<
c0198c64>] (debug_dma_unmap_page+0x0/0x80) from [<
c01d5ad8>] (omap2_mcspi_work+0x514/0xbf0)
[<
c01d55c4>] (omap2_mcspi_work+0x0/0xbf0) from [<
c006dfb0>] (process_one_work+0x294/0x400)
[<
c006dd1c>] (process_one_work+0x0/0x400) from [<
c006e50c>] (worker_thread+0x220/0x3f8)
[<
c006e2ec>] (worker_thread+0x0/0x3f8) from [<
c00738d0>] (kthread+0x88/0x90)
[<
c0073848>] (kthread+0x0/0x90) from [<
c005e924>] (do_exit+0x0/0x5fc)
r7:
00000013 r6:
c005e924 r5:
c0073848 r4:
c1829ee0
---[ end trace
1b75b31a2719ed20 ]---
I've no idea why this driver uses NULL for dma_unmap_single instead of
the &spi->dev that is laying around just waiting to be used in that
function - but it's an easy fix.
Also replace this comment with a FIXME comment:
/* Do DMA mapping "early" for better error reporting and
* dcache use. Note that if dma_unmap_single() ever starts
* to do real work on ARM, we'd need to clean up mappings
* for previous transfers on *ALL* exits of this loop...
*/
as the comment is not true - we do work in dma_unmap() functions,
particularly on ARMv6 and above. I've corrected the existing unmap
functions but if any others are required they must be added ASAP.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Richard Genoud [Fri, 7 Jan 2011 14:26:01 +0000 (15:26 +0100)]
spi/imx: correct the test on platform_get_irq() return value
The test "if (spi_imx->irq <= 0)" is not testing the IRQ value, but
the return value of platform_get_irq(). As platform_get_irq() can
return an error (-ENXIO) or the IRQ value it found, the test should be
"if (spi_imx->irq < 0)"
[grant.likely: Note: In general, Linux irq number 0 should also mean
no irq, but arm still allows devices to be assigned 0, and the imx
platform uses 0 for one of the spi devices, so this patch is needed
for the device to work]
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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
...
Peter Zijlstra [Fri, 7 Jan 2011 12:41:40 +0000 (13:41 +0100)]
sched: Constify function scope static struct sched_param usage
Function-scope statics are discouraged because they are
easily overlooked and can cause subtle bugs/races due to
their global (non-SMP safe) nature.
Linus noticed that we did this for sched_param - at minimum
make the const.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: Message-ID: <AANLkTinotRxScOHEb0HgFgSpGPkq_6jKTv5CfvnQM=ee@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Hillf Danton [Thu, 6 Jan 2011 12:58:12 +0000 (20:58 +0800)]
sched: Fix strncmp operation
One of the operands, buf, is incorrect, since it is stripped and the
correct address for subsequent string comparing could change if
leading white spaces, if any, are removed from buf.
It is fixed by replacing buf with cmp.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <AANLkTinOPuYsVovrZpbuCCmG5deEyc8WgA_A1RJx_YK7@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mike Galbraith [Wed, 5 Jan 2011 10:16:04 +0000 (11:16 +0100)]
sched: Move sched_autogroup_exit() to free_signal_struct()
Per Oleg's suggestion, undo fork failure free/put_signal_struct change,
and move sched_autogroup_exit() to free_signal_struct() instead.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <
1294222564.8369.6.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mike Galbraith [Wed, 5 Jan 2011 10:11:25 +0000 (11:11 +0100)]
sched: Fix struct autogroup memory leak
Seems I lost a change somewhere, leaking memory.
sched: fix struct autogroup memory leak
Add missing change to actually use autogroup_free().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <
1294222285.8369.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Yong Zhang [Fri, 7 Jan 2011 04:43:45 +0000 (12:43 +0800)]
sched: Mark autogroup_init() __init
autogroup_init() is only called at boot time.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <
1294375425-31065-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Yong Zhang [Fri, 7 Jan 2011 07:17:36 +0000 (15:17 +0800)]
sched: Consolidate the name of root_task_group and init_task_group
root_task_group is the leftover of USER_SCHED, now it's always
same to init_task_group.
But as Mike suggested, root_task_group is maybe the suitable name
to keep for a tree.
So in this patch:
init_task_group --> root_task_group
init_task_group_load --> root_task_group_load
INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD
Suggested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <
20110107071736.GA32635@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo Molnar [Fri, 7 Jan 2011 13:14:15 +0000 (14:14 +0100)]
Merge branch 'linus' into x86/apic-cleanups
Conflicts:
arch/x86/include/asm/io_apic.h
Merge reason: Resolve the conflict, update to a more recent -rc base
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Borislav Petkov [Thu, 25 Nov 2010 14:40:27 +0000 (15:40 +0100)]
EDAC, MCE: Fix NB error formatting
Minor formatting fixup since the information which core was associated
with the MCE is not always valid.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Randy Dunlap [Sat, 13 Nov 2010 16:44:26 +0000 (11:44 -0500)]
EDAC, MCE: Use BIT_64() to eliminate warnings on 32-bit
Building for X86_32 produces shift count warnings, so use BIT_64() to
eliminate the warnings.
drivers/edac/mce_amd.c:778: warning: left shift count >= width of type
drivers/edac/mce_amd.c:778: warning: left shift count >= width of type
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: bluesmoke-devel@lists.sourceforge.net
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 15:44:51 +0000 (17:44 +0200)]
EDAC, MCE: Enable MCE decoding on F15h
Now that everything is inplace, enable MCE decoding on F15h. Make
initcall routine a bit more readable.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Tue, 9 Nov 2010 18:41:49 +0000 (19:41 +0100)]
EDAC, MCE: Allow F15h bank 6 MCE injection
F15h adds a sixth MCE bank: adjust bank number check in the injection
code.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 15:42:27 +0000 (17:42 +0200)]
EDAC, MCE: Shorten error report formatting
Shorten up MCi_STATUS flags and add BD's new deferred and poison types.
Also, simplify formatting.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 14:08:37 +0000 (16:08 +0200)]
EDAC, MCE: Overhaul error fields extraction macros
Make macro names shorter thus making code shorter and more clear.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 13:37:58 +0000 (15:37 +0200)]
EDAC, MCE: Add F15h FP MCE decoder
Add decoder for FP MCEs.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 13:28:59 +0000 (15:28 +0200)]
EDAC, MCE: Add F15 EX MCE decoder
Integrate the single FIROB signature into an expanded table along with
the new BD MCE types.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 13:06:24 +0000 (15:06 +0200)]
EDAC, MCE: Add an F15h NB MCE decoder
by (almost) reusing the F10h one since the signatures are the same.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Wed, 22 Sep 2010 09:53:32 +0000 (11:53 +0200)]
EDAC, MCE: No F15h LS MCE decoder
F15h BD doesn't generate LS MCEs so warn about it.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Tue, 21 Sep 2010 18:45:10 +0000 (20:45 +0200)]
EDAC, MCE: Add F15h CU MCE decoder
MCE bank 2 is redefined from a BU to a CU (Combined Unit) bank on F15h.
Add a decoder function for CU MCEs.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Mon, 8 Nov 2010 14:03:35 +0000 (15:03 +0100)]
EDAC, MCE: Add F15h IC MCE decoder
Add support for decoding F15h IC MCEs.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 17 Sep 2010 17:22:34 +0000 (19:22 +0200)]
EDAC, MCE: Add F15h DC MCE decoder
Add a decoder for F15h DC MCEs to support the new types of DC MCEs
introduced by the BD microarchitecture.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Borislav Petkov [Fri, 17 Sep 2010 17:11:47 +0000 (19:11 +0200)]
EDAC, MCE: Select extended error code mask
F15h enlarges the extended error code of an MCE to a 5-bit field
(MCi_STATUS[20:16]). Add a mask variable which default 0xf is overridden
on F15h.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
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>