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2011-01-07Merge branch 'rmobile-latest' of ↵Linus Torvalds40-220/+6904
git://git.kernel.org/pub/scm/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 ...
2011-01-07Merge branch 'for-linus' of ↵Linus Torvalds64-753/+3209
git://git.kernel.org/pub/scm/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
2011-01-07Merge branch 'tty-next' of ↵Linus Torvalds45-189/+4538
git://git.kernel.org/pub/scm/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).
2011-01-07Merge branch 'usb-next' of ↵Linus Torvalds136-1999/+15389
git://git.kernel.org/pub/scm/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
2011-01-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds161-7312/+11139
* 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. ...
2011-01-07input/tc3589x: fix compile errorDan Carpenter1-1/+1
There was a semi-colon missing and it broke the compile. Signed-off-by: Dan Carpenter <[email protected]> Cc: Dmitry Torokhov <[email protected]> Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-01-07spi/omap: Fix DMA API usage in OMAP MCSPI driverRussell King - ARM Linux1-8/+3
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 <[email protected]> Acked-by: Tony Lindgren <[email protected]> Signed-off-by: Grant Likely <[email protected]>
2011-01-07spi/imx: correct the test on platform_get_irq() return valueRichard Genoud1-1/+1
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 <[email protected]> Signed-off-by: Grant Likely <[email protected]>
2011-01-07Merge branch 'vfs-scale-working' of ↵Linus Torvalds212-2014/+4774
git://git.kernel.org/pub/scm/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 ...
2011-01-07sched: Constify function scope static struct sched_param usagePeter Zijlstra4-4/+4
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 <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: Message-ID: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-01-07sched: Fix strncmp operationHillf Danton1-1/+1
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 <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-01-07sched: Move sched_autogroup_exit() to free_signal_struct()Mike Galbraith1-4/+3
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 <[email protected]> Reviewed-by: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-01-07sched: Fix struct autogroup memory leakMike Galbraith1-0/+1
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 <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-01-07sched: Mark autogroup_init() __initYong Zhang1-1/+1
autogroup_init() is only called at boot time. Signed-off-by: Yong Zhang <[email protected]> Cc: Mike Galbraith <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-01-07sched: Consolidate the name of root_task_group and init_task_groupYong Zhang3-26/+24
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 <[email protected]> Signed-off-by: Yong Zhang <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-01-07Merge branch 'linus' into x86/apic-cleanupsIngo Molnar1847-17977/+32473
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 <[email protected]>
2011-01-07EDAC, MCE: Fix NB error formattingBorislav Petkov1-7/+10
Minor formatting fixup since the information which core was associated with the MCE is not always valid. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Use BIT_64() to eliminate warnings on 32-bitRandy Dunlap1-2/+2
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 <[email protected]> Cc: Doug Thompson <[email protected]> Cc: [email protected] Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Enable MCE decoding on F15hBorislav Petkov1-6/+8
Now that everything is inplace, enable MCE decoding on F15h. Make initcall routine a bit more readable. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Allow F15h bank 6 MCE injectionBorislav Petkov1-4/+5
F15h adds a sixth MCE bank: adjust bank number check in the injection code. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Shorten error report formattingBorislav Petkov1-22/+32
Shorten up MCi_STATUS flags and add BD's new deferred and poison types. Also, simplify formatting. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Overhaul error fields extraction macrosBorislav Petkov3-54/+43
Make macro names shorter thus making code shorter and more clear. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Add F15h FP MCE decoderBorislav Petkov1-0/+44
Add decoder for FP MCEs. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Add F15 EX MCE decoderBorislav Petkov1-7/+34
Integrate the single FIROB signature into an expanded table along with the new BD MCE types. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Add an F15h NB MCE decoderBorislav Petkov1-0/+10
by (almost) reusing the F10h one since the signatures are the same. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: No F15h LS MCE decoderBorislav Petkov1-1/+1
F15h BD doesn't generate LS MCEs so warn about it. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Add F15h CU MCE decoderBorislav Petkov1-1/+61
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 <[email protected]>
2011-01-07EDAC, MCE: Add F15h IC MCE decoderBorislav Petkov2-4/+51
Add support for decoding F15h IC MCEs. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07EDAC, MCE: Add F15h DC MCE decoderBorislav Petkov2-19/+62
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 <[email protected]>
2011-01-07EDAC, MCE: Select extended error code maskBorislav Petkov1-4/+9
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 <[email protected]>
2011-01-07amd64_edac: Disable DRAM ECC injection on K8Borislav Petkov1-2/+3
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 <[email protected]>
2011-01-07EDAC: Fixup scrubrate manipulationBorislav Petkov7-63/+52
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 <[email protected]>
2011-01-07amd64_edac: Remove two-stage initializationBorislav Petkov1-100/+68
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 <[email protected]>
2011-01-07amd64_edac: Check ECC capabilities initiallyBorislav Petkov1-66/+75
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 <[email protected]>
2011-01-07amd64_edac: Carve out ECC-related hw settingsBorislav Petkov2-24/+49
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 <[email protected]>
2011-01-07amd64_edac: Remove PCI ECS enabling functionsBorislav Petkov2-59/+0
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 <[email protected]>
2011-01-07amd64_edac: Remove explicit Kconfig PCI dependencyBorislav Petkov1-4/+4
AMD_NB pulls in the dependency on PCI. Clarify/fix help text while at it. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07amd64_edac: Allocate driver instances dynamicallyBorislav Petkov2-18/+29
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 <[email protected]>
2011-01-07amd64_edac: Rework printk macrosBorislav Petkov5-107/+87
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 <[email protected]>
2011-01-07amd64_edac: Rename CPU PCI devicesBorislav Petkov3-95/+77
Rename variables representing PCI devices to their BKDG names for faster search and shorter, clearer code. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07amd64_edac: Concentrate per-family init even moreBorislav Petkov2-29/+17
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 <[email protected]>
2011-01-07amd64_edac: Cleanup the CPU PCI device reservationBorislav Petkov1-30/+12
Shorten code and clarify comments, return proper -E* values on error. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07amd64_edac: Simplify CPU family detectionBorislav Petkov2-32/+32
Concentrate CPU family detection in the per-family init function. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07amd64_edac: Add per-family init functionBorislav Petkov2-19/+28
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 <[email protected]>
2011-01-07amd64_edac: Use cached extended CPU modelBorislav Petkov1-3/+2
... instead of computing it needlessly again. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07amd64_edac: Remove F11h supportBorislav Petkov2-49/+3
F11h doesn't support DRAM ECC so whack it away. Signed-off-by: Borislav Petkov <[email protected]>
2011-01-07fs: scale mntget/mntputNick Piggin13-98/+283
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 <[email protected]>
2011-01-07fs: rename vfsmount counter helpersNick Piggin1-11/+11
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 <[email protected]>
2011-01-07fs: implement faster dentry memcmpNick Piggin2-9/+24
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 <[email protected]>
2011-01-07fs: prefetch inode data in dcache lookupNick Piggin1-0/+3
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 <[email protected]>
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