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* cgroup/cpuset: remove circular dependency deadlockPrateek Sood2017-09-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove circular dependency deadlock in a scenario where hotplug of CPU is being done while there is updation in cgroup and cpuset triggered from userspace. Process A => kthreadd => Process B => Process C => Process A Process A cpu_subsys_offline(); cpu_down(); _cpu_down(); mutex_lock(&cpuhotplug.lock); //held __cpu_notify(); workqueue_cpu_down_callback(); queue_work_on(system_highpri_wq); __queue_work(); insert_work(); wake_up_worker(); //pool->nr_running = 0 flush_work(); wait_for_completion(); worker_thread(); need_more_worker(); // returns true manage_workers(); maybe_create_worker(); create_worker(); kthread_create_on_node(); wake_up_process(kthreadd_task); kthreadd kthreadd(); kernel_thread(); do_fork(); copy_process(); percpu_down_read(&cgroup_threadgroup_rwsem); __rwsem_down_read_failed_common(); //waiting Process B kernfs_fop_write(); cgroup_file_write(); cgroup_tasks_write(); percpu_down_write(&cgroup_threadgroup_rwsem); //held cgroup_attach_task(); cgroup_migrate(); cgroup_taskset_migrate(); cpuset_can_attach(); mutex_lock(&cpuset_mutex); //waiting Process C kernfs_fop_write(); cgroup_file_write(); cpuset_write_resmask(); mutex_lock(&cpuset_mutex); //held update_cpumask(); update_cpumasks_hier(); rebuild_sched_domains_locked(); get_online_cpus(); mutex_lock(&cpuhotplug.lock); //waiting Eliminate this dependecy by reordering locking of cpuset_mutex and cpuhotplug.lock. Change-Id: Ifd76373d717c53b531623a3be76b7d32e0d959fd Signed-off-by: Prateek Sood <prsood@codeaurora.org>
* Merge tag 'lsk-v4.4-17.02-android' into branch 'msm-4.4'Runmin Wang2017-03-18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-26c8156: Linux 4.4.49 drm/i915: fix use-after-free in page_flip_completed() ALSA: seq: Don't handle loop timeout at snd_seq_pool_done() ALSA: seq: Fix race at creating a queue xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend() scsi: mpt3sas: disable ASPM for MPI2 controllers scsi: aacraid: Fix INTx/MSI-x issue with older controllers scsi: zfcp: fix use-after-free by not tracing WKA port open/close on failed send netvsc: Set maximum GSO size in the right place mac80211: Fix adding of mesh vendor IEs ARM: 8642/1: LPAE: catch pending imprecise abort on unmask target: Fix COMPARE_AND_WRITE ref leak for non GOOD status target: Fix early transport_generic_handle_tmr abort scenario target: Use correct SCSI status during EXTENDED_COPY exception target: Don't BUG_ON during NodeACL dynamic -> explicit conversion ARM: 8643/3: arm/ptrace: Preserve previous registers for short regset write hns: avoid stack overflow with CONFIG_KASAN cpumask: use nr_cpumask_bits for parsing functions Revert "x86/ioapic: Restore IO-APIC irq_chip retrigger callback" selinux: fix off-by-one in setprocattr ARC: [arcompact] brown paper bag bug in unaligned access delay slot fixup Linux 4.4.48 base/memory, hotplug: fix a kernel oops in show_valid_zones() x86/irq: Make irq activate operations symmetric USB: serial: option: add device ID for HP lt2523 (Novatel E371) usb: gadget: f_fs: Assorted buffer overflow checks. USB: Add quirk for WORLDE easykey.25 MIDI keyboard USB: serial: pl2303: add ATEN device ID USB: serial: qcserial: add Dell DW5570 QDL KVM: x86: do not save guest-unsupported XSAVE state HID: wacom: Fix poor prox handling in 'wacom_pl_irq' percpu-refcount: fix reference leak during percpu-atomic transition mmc: sdhci: Ignore unexpected CARD_INT interrupts can: bcm: fix hrtimer/tasklet termination in bcm op removal mm, fs: check for fatal signals in do_generic_file_read() mm/memory_hotplug.c: check start_pfn in test_pages_in_a_zone() cifs: initialize file_info_lock zswap: disable changing params if init fails svcrpc: fix oops in absence of krb5 module NFSD: Fix a null reference case in find_or_create_lock_stateid() powerpc: Add missing error check to prom_find_boot_cpu() powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe() libata: apply MAX_SEC_1024 to all CX1-JB*-HP devices ata: sata_mv:- Handle return value of devm_ioremap. perf/core: Fix PERF_RECORD_MMAP2 prot/flags for anonymous memory crypto: arm64/aes-blk - honour iv_out requirement in CBC and CTR modes crypto: api - Clear CRYPTO_ALG_DEAD bit before registering an alg drm/nouveau/nv1a,nv1f/disp: fix memory clock rate retrieval drm/nouveau/disp/gt215: Fix HDA ELD handling (thus, HDMI audio) on gt215 ext4: validate s_first_meta_bg at mount time PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies ANDROID: security: export security_path_chown() Linux 4.4.47 net: dsa: Bring back device detaching in dsa_slave_suspend() qmi_wwan/cdc_ether: add device ID for HP lt2523 (Novatel E371) WWAN card af_unix: move unix_mknod() out of bindlock r8152: don't execute runtime suspend if the tx is not empty bridge: netlink: call br_changelink() during br_dev_newlink() tcp: initialize max window for a new fastopen socket ipv6: addrconf: Avoid addrconf_disable_change() using RCU read-side lock net: phy: bcm63xx: Utilize correct config_intr function net: fix harmonize_features() vs NETIF_F_HIGHDMA ax25: Fix segfault after sock connection timeout ravb: do not use zero-length alignment DMA descriptor openvswitch: maintain correct checksum state in conntrack actions tcp: fix tcp_fastopen unaligned access complaints on sparc net: systemport: Decouple flow control from __bcm_sysport_tx_reclaim net: ipv4: fix table id in getroute response net: lwtunnel: Handle lwtunnel_fill_encap failure mlxsw: pci: Fix EQE structure definition mlxsw: switchx2: Fix memory leak at skb reallocation mlxsw: spectrum: Fix memory leak at skb reallocation r8152: fix the sw rx checksum is unavailable ANDROID: sdcardfs: Switch strcasecmp for internal call ANDROID: sdcardfs: switch to full_name_hash and qstr ANDROID: sdcardfs: Add GID Derivation to sdcardfs ANDROID: sdcardfs: Remove redundant operation ANDROID: sdcardfs: add support for user permission isolation ANDROID: sdcardfs: Refactor configfs interface ANDROID: sdcardfs: Allow non-owners to touch ANDROID: binder: fix format specifier for type binder_size_t ANDROID: fs: Export vfs_rmdir2 ANDROID: fs: Export free_fs_struct and set_fs_pwd ANDROID: mnt: remount should propagate to slaves of slaves ANDROID: sdcardfs: Switch ->d_inode to d_inode() ANDROID: sdcardfs: Fix locking issue with permision fix up ANDROID: sdcardfs: Change magic value ANDROID: sdcardfs: Use per mount permissions ANDROID: sdcardfs: Add gid and mask to private mount data ANDROID: sdcardfs: User new permission2 functions ANDROID: vfs: Add setattr2 for filesystems with per mount permissions ANDROID: vfs: Add permission2 for filesystems with per mount permissions ANDROID: vfs: Allow filesystems to access their private mount data ANDROID: mnt: Add filesystem private data to mount points ANDROID: sdcardfs: Move directory unlock before touch ANDROID: sdcardfs: fix external storage exporting incorrect uid ANDROID: sdcardfs: Added top to sdcardfs_inode_info ANDROID: sdcardfs: Switch package list to RCU ANDROID: sdcardfs: Fix locking for permission fix up ANDROID: sdcardfs: Check for other cases on path lookup ANDROID: sdcardfs: override umask on mkdir and create Linux 4.4.46 mm, memcg: do not retry precharge charges platform/x86: intel_mid_powerbtn: Set IRQ_ONESHOT pinctrl: broxton: Use correct PADCFGLOCK offset s5k4ecgx: select CRC32 helper IB/umem: Release pid in error and ODP flow IB/ipoib: move back IB LL address into the hard header drm/i915: Don't leak edid in intel_crt_detect_ddc() SUNRPC: cleanup ida information when removing sunrpc module NFSv4.0: always send mode in SETATTR after EXCLUSIVE4 nfs: Don't increment lock sequence ID after NFS4ERR_MOVED parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header ARC: [arcompact] handle unaligned access delay slot corner case ARC: udelay: fix inline assembler by adding LP_COUNT to clobber list can: ti_hecc: add missing prepare and unprepare of the clock can: c_can_pci: fix null-pointer-deref in c_can_start() - set device pointer s390/ptrace: Preserve previous registers for short regset write RDMA/cma: Fix unknown symbol when CONFIG_IPV6 is not enabled ISDN: eicon: silence misleading array-bounds warning sysctl: fix proc_doulongvec_ms_jiffies_minmax() mm/mempolicy.c: do not put mempolicy before using its nodemask drm: Fix broken VT switch with video=1366x768 option tile/ptrace: Preserve previous registers for short regset write fbdev: color map copying bounds checking Linux 4.4.45 arm64: avoid returning from bad_mode selftest/powerpc: Wrong PMC initialized in pmc56_overflow test dmaengine: pl330: Fix runtime PM support for terminated transfers ite-cir: initialize use_demodulator before using it blackfin: check devm_pinctrl_get() for errors ARM: 8613/1: Fix the uaccess crash on PB11MPCore ARM: ux500: fix prcmu_is_cpu_in_wfi() calculation ARM: dts: imx6qdl-nitrogen6_max: fix sgtl5000 pinctrl init arm64/ptrace: Reject attempts to set incomplete hardware breakpoint fields arm64/ptrace: Avoid uninitialised struct padding in fpr_set() arm64/ptrace: Preserve previous registers for short regset write - 3 arm64/ptrace: Preserve previous registers for short regset write - 2 arm64/ptrace: Preserve previous registers for short regset write ARM: dts: da850-evm: fix read access to SPI flash ceph: fix bad endianness handling in parse_reply_info_extra ARM: 8634/1: hw_breakpoint: blacklist Scorpion CPUs svcrdma: avoid duplicate dma unmapping during error recovery clocksource/exynos_mct: Clear interrupt when cpu is shut down ubifs: Fix journal replay wrt. xattr nodes qla2xxx: Fix crash due to null pointer access x86/ioapic: Restore IO-APIC irq_chip retrigger callback mtd: nand: xway: disable module support ieee802154: atusb: do not use the stack for buffers to make them DMA able mmc: mxs-mmc: Fix additional cycles after transmission stop HID: corsair: fix control-transfer error handling HID: corsair: fix DMA buffers on stack PCI: Enumerate switches below PCI-to-PCIe bridges fuse: clear FR_PENDING flag when moving requests out of pending queue svcrpc: don't leak contexts on PROC_DESTROY x86/PCI: Ignore _CRS on Supermicro X8DTH-i/6/iF/6F tmpfs: clear S_ISGID when setting posix ACLs ARM: dts: imx31: fix AVIC base address ARM: dts: imx31: move CCM device node to AIPS2 bus devices ARM: dts: imx31: fix clock control module interrupts description perf scripting: Avoid leaking the scripting_context variable IB/IPoIB: Remove can't use GFP_NOIO warning IB/mlx4: When no DMFS for IPoIB, don't allow NET_IF QPs IB/mlx4: Fix port query for 56Gb Ethernet links IB/mlx4: Fix out-of-range array index in destroy qp flow IB/mlx4: Set traffic class in AH IB/mlx5: Wait for all async command completions to complete ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it Linux 4.4.44 pinctrl: sh-pfc: Do not unconditionally support PIN_CONFIG_BIAS_DISABLE powerpc/ibmebus: Fix device reference leaks in sysfs interface powerpc/ibmebus: Fix further device reference leaks bus: vexpress-config: fix device reference leak blk-mq: Always schedule hctx->next_cpu ACPI / APEI: Fix NMI notification handling block: cfq_cpd_alloc() should use @gfp cpufreq: powernv: Disable preemption while checking CPU throttling state NFSv4.1: nfs4_fl_prepare_ds must be careful about reporting success. NFS: Fix a performance regression in readdir pNFS: Fix race in pnfs_wait_on_layoutreturn pinctrl: meson: fix gpio request disabling other modes btrfs: fix error handling when run_delayed_extent_op fails btrfs: fix locking when we put back a delayed ref that's too new x86/cpu: Fix bootup crashes by sanitizing the argument of the 'clearcpuid=' command-line option USB: serial: ch341: fix modem-control and B0 handling USB: serial: ch341: fix resume after reset drm/radeon: drop verde dpm quirks sysctl: Drop reference added by grab_header in proc_sys_readdir sysrq: attach sysrq handler correctly for 32-bit kernel tty/serial: atmel_serial: BUG: stop DMA from transmitting in stop_tx mnt: Protect the mountpoint hashtable with mount_lock vme: Fix wrong pointer utilization in ca91cx42_slave_get xhci: fix deadlock at host remove by running watchdog correctly i2c: fix kernel memory disclosure in dev interface i2c: print correct device invalid address Input: elants_i2c - avoid divide by 0 errors on bad touchscreen data USB: serial: ch341: fix open and resume after B0 USB: serial: ch341: fix control-message error handling USB: serial: ch341: fix open error handling USB: serial: ch341: fix initial modem-control state USB: serial: kl5kusb105: fix line-state error handling nl80211: fix sched scan netlink socket owner destruction KVM: x86: Introduce segmented_write_std KVM: x86: emulate FXSAVE and FXRSTOR KVM: x86: add asm_safe wrapper KVM: x86: add Align16 instruction flag KVM: x86: flush pending lapic jump label updates on module unload jump_labels: API for flushing deferred jump label updates KVM: eventfd: fix NULL deref irqbypass consumer KVM: x86: fix emulation of "MOV SS, null selector" mm/hugetlb.c: fix reservation race when freeing surplus pages ocfs2: fix crash caused by stale lvb with fsdlm plugin mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done} selftests: do not require bash for the generated test selftests: do not require bash to run netsocktests testcase Input: i8042 - add Pegatron touchpad to noloop table Input: xpad - use correct product id for x360w controllers DEBUG: sched/fair: Fix sched_load_avg_cpu events for task_groups DEBUG: sched/fair: Fix missing sched_load_avg_cpu events net: socket: don't set sk_uid to garbage value in ->setattr() ANDROID: configs: CONFIG_ARM64_SW_TTBR0_PAN=y UPSTREAM: arm64: Disable PAN on uaccess_enable() UPSTREAM: arm64: Enable CONFIG_ARM64_SW_TTBR0_PAN UPSTREAM: arm64: xen: Enable user access before a privcmd hvc call UPSTREAM: arm64: Handle faults caused by inadvertent user access with PAN enabled BACKPORT: arm64: Disable TTBR0_EL1 during normal kernel execution BACKPORT: arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1 BACKPORT: arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro BACKPORT: arm64: Factor out PAN enabling/disabling into separate uaccess_* macros UPSTREAM: arm64: alternative: add auto-nop infrastructure UPSTREAM: arm64: barriers: introduce nops and __nops macros for NOP sequences Revert "FROMLIST: arm64: Factor out PAN enabling/disabling into separate uaccess_* macros" Revert "FROMLIST: arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro" Revert "FROMLIST: arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1" Revert "FROMLIST: arm64: Disable TTBR0_EL1 during normal kernel execution" Revert "FROMLIST: arm64: Handle faults caused by inadvertent user access with PAN enabled" Revert "FROMLIST: arm64: xen: Enable user access before a privcmd hvc call" Revert "FROMLIST: arm64: Enable CONFIG_ARM64_SW_TTBR0_PAN" ANDROID: sched/walt: fix build failure if FAIR_GROUP_SCHED=n Linux 4.4.43 mm/init: fix zone boundary creation ALSA: usb-audio: Add a quirk for Plantronics BT600 spi: mvebu: fix baudrate calculation for armada variant ARM: OMAP4+: Fix bad fallthrough for cpuidle ARM: zynq: Reserve correct amount of non-DMA RAM powerpc: Fix build warning on 32-bit PPC ALSA: firewire-tascam: Fix to handle error from initialization of stream data HID: hid-cypress: validate length of report net: vrf: do not allow table id 0 net: ipv4: Fix multipath selection with vrf gro: Disable frag0 optimization on IPv6 ext headers gro: use min_t() in skb_gro_reset_offset() gro: Enter slow-path if there is no tailroom r8152: fix rx issue for runtime suspend r8152: split rtl8152_suspend function ipv4: Do not allow MAIN to be alias for new LOCAL w/ custom rules igmp: Make igmp group member RFC 3376 compliant drop_monitor: consider inserted data in genlmsg_end drop_monitor: add missing call to genlmsg_end net/mlx5: Avoid shadowing numa_node net/mlx5: Check FW limitations on log_max_qp before setting it net: stmmac: Fix race between stmmac_drv_probe and stmmac_open net, sched: fix soft lockup in tc_classify ipv6: handle -EFAULT from skb_copy_bits net: vrf: Drop conntrack data after pass through VRF device on Tx ser_gigaset: return -ENOMEM on error instead of success netvsc: reduce maximum GSO size Linux 4.4.42 usb: gadget: composite: always set ep->mult to a sensible value Revert "usb: gadget: composite: always set ep->mult to a sensible value" tick/broadcast: Prevent NULL pointer dereference drm/radeon: Always store CRTC relative radeon_crtc->cursor_x/y values cx23885-dvb: move initialization of a8293_pdata net: vxge: avoid unused function warnings net: ti: cpmac: Fix compiler warning due to type confusion cred/userns: define current_user_ns() as a function staging: comedi: dt282x: tidy up register bit defines powerpc/pci/rpadlpar: Fix device reference leaks md: MD_RECOVERY_NEEDED is set for mddev->recovery crypto: arm64/aes-ce - fix for big endian crypto: arm64/aes-xts-ce: fix for big endian crypto: arm64/sha1-ce - fix for big endian crypto: arm64/aes-neon - fix for big endian crypto: arm64/aes-ccm-ce: fix for big endian crypto: arm/aes-ce - fix for big endian crypto: arm64/ghash-ce - fix for big endian crypto: arm64/sha2-ce - fix for big endian s390/crypto: unlock on error in prng_tdes_read() mmc: mmc_test: Uninitialized return value PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend irqchip/bcm7038-l1: Implement irq_cpu_offline() callback target/iscsi: Fix double free in lio_target_tiqn_addtpg() scsi: mvsas: fix command_active typo ASoC: samsung: i2s: Fixup last IRQ unsafe spin lock call iommu/vt-d: Flush old iommu caches for kdump when the device gets context mapped iommu/vt-d: Fix pasid table size encoding iommu/amd: Fix the left value check of cmd buffer iommu/amd: Missing error code in amd_iommu_init_device() clk: imx31: fix rewritten input argument of mx31_clocks_init() clk: clk-wm831x: fix a logic error hwmon: (g762) Fix overflows and crash seen when writing limit attributes hwmon: (nct7802) Fix overflows seen when writing into limit attributes hwmon: (ds620) Fix overflows seen when writing temperature limits hwmon: (amc6821) sign extension temperature hwmon: (scpi) Fix module autoload cris: Only build flash rescue image if CONFIG_ETRAX_AXISFLASHMAP is selected ath10k: use the right length of "background" stable-fixup: hotplug: fix unused function warning usb: dwc3: ep0: explicitly call dwc3_ep0_prepare_one_trb() usb: dwc3: ep0: add dwc3_ep0_prepare_one_trb() usb: dwc3: gadget: always unmap EP0 requests staging: iio: ad7606: fix improper setting of oversampling pins mei: bus: fix mei_cldev_enable KDoc USB: serial: io_ti: bind to interface after fw download USB: phy: am335x-control: fix device and of_node leaks ARM: dts: r8a7794: Correct hsusb parent clock USB: serial: kl5kusb105: abort on open exception path ALSA: usb-audio: Fix bogus error return in snd_usb_create_stream() usb: musb: blackfin: add bfin_fifo_offset in bfin_ops usb: hub: Move hub_port_disable() to fix warning if PM is disabled usb: musb: Fix trying to free already-free IRQ 4 usb: dwc3: pci: add Intel Gemini Lake PCI ID xhci: Fix race related to abort operation xhci: Use delayed_work instead of timer for command timeout usb: xhci-mem: use passed in GFP flags instead of GFP_KERNEL USB: serial: mos7720: fix parallel probe USB: serial: mos7720: fix parport use-after-free on probe errors USB: serial: mos7720: fix use-after-free on probe errors USB: serial: mos7720: fix NULL-deref at open USB: serial: mos7840: fix NULL-deref at open USB: serial: kobil_sct: fix NULL-deref in write USB: serial: cyberjack: fix NULL-deref at open USB: serial: oti6858: fix NULL-deref at open USB: serial: io_edgeport: fix NULL-deref at open USB: serial: ti_usb_3410_5052: fix NULL-deref at open USB: serial: garmin_gps: fix memory leak on failed URB submit USB: serial: iuu_phoenix: fix NULL-deref at open USB: serial: io_ti: fix I/O after disconnect USB: serial: io_ti: fix another NULL-deref at open USB: serial: io_ti: fix NULL-deref at open USB: serial: spcp8x5: fix NULL-deref at open USB: serial: keyspan_pda: verify endpoints at probe USB: serial: pl2303: fix NULL-deref at open USB: serial: quatech2: fix sleep-while-atomic in close USB: serial: omninet: fix NULL-derefs at open and disconnect usb: xhci: hold lock over xhci_abort_cmd_ring() xhci: Handle command completion and timeout race usb: host: xhci: Fix possible wild pointer when handling abort command usb: xhci: fix return value of xhci_setup_device() xhci: free xhci virtual devices with leaf nodes first usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Apollo Lake xhci: workaround for hosts missing CAS bit usb: xhci: fix possible wild pointer usb: dwc3: core: avoid Overflow events usb: gadget: composite: Test get_alt() presence instead of set_alt() USB: dummy-hcd: fix bug in stop_activity (handle ep0) USB: fix problems with duplicate endpoint addresses USB: gadgetfs: fix checks of wTotalLength in config descriptors USB: gadgetfs: fix use-after-free bug USB: gadgetfs: fix unbounded memory allocation bug usb: gadgetfs: restrict upper bound on device configuration size usb: storage: unusual_uas: Add JMicron JMS56x to unusual device usb: musb: dsps: implement clear_ep_rxintr() callback usb: musb: core: add clear_ep_rxintr() to musb_platform_ops KVM: MIPS: Flush KVM entry code from icache globally KVM: x86: reset MMU on KVM_SET_VCPU_EVENTS mac80211: initialize fast-xmit 'info' later ARM: davinci: da850: don't add emac clock to lookup table twice ALSA: usb-audio: Fix irq/process data synchronization ALSA: hda - Apply asus-mode8 fixup to ASUS X71SL ALSA: hda - Fix up GPIO for ASUS ROG Ranger Linux 4.4.41 net: mvpp2: fix dma unmapping of TX buffers for fragments sg_write()/bsg_write() is not fit to be called under KERNEL_DS kconfig/nconf: Fix hang when editing symbol with a long prompt target/user: Fix use-after-free of tcmu_cmds if they are expired powerpc: Convert cmp to cmpd in idle enter sequence powerpc/ps3: Fix system hang with GCC 5 builds nfs_write_end(): fix handling of short copies libceph: verify authorize reply on connect PCI: Check for PME in targeted sleep state Input: drv260x - fix input device's parent assignment media: solo6x10: fix lockup by avoiding delayed register write IB/cma: Fix a race condition in iboe_addr_get_sgid() IB/multicast: Check ib_find_pkey() return value IPoIB: Avoid reading an uninitialized member variable IB/mad: Fix an array index check fgraph: Handle a case where a tracer ignores set_graph_notrace platform/x86: asus-nb-wmi.c: Add X45U quirk ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it kvm: nVMX: Allow L1 to intercept software exceptions (#BP and #OF) KVM: PPC: Book3S HV: Don't lose hardware R/C bit updates in H_PROTECT KVM: PPC: Book3S HV: Save/restore XER in checkpointed register state md/raid5: limit request size according to implementation limits sc16is7xx: Drop bogus use of IRQF_ONESHOT s390/vmlogrdr: fix IUCV buffer allocation firmware: fix usermode helper fallback loading ARC: mm: arc700: Don't assume 2 colours for aliasing VIPT dcache scsi: avoid a permanent stop of the scsi device's request queue scsi: zfcp: fix rport unblock race with LUN recovery scsi: zfcp: do not trace pure benign residual HBA responses at default level scsi: zfcp: fix use-after-"free" in FC ingress path after TMF scsi: megaraid_sas: Do not set MPI2_TYPE_CUDA for JBOD FP path for FW which does not support JBOD sequence map scsi: megaraid_sas: For SRIOV enabled firmware, ensure VF driver waits for 30secs before reset vt: fix Scroll Lock LED trigger name block: protect iterate_bdevs() against concurrent close mei: request async autosuspend at the end of enumeration drivers/gpu/drm/ast: Fix infinite loop if read fails drm/gma500: Add compat ioctl drm/radeon: add additional pci revision to dpm workaround drm/radeon: Hide the HW cursor while it's out of bounds drm/radeon: Also call cursor_move_locked when the cursor size changes drm/nouveau/i2c/gk110b,gm10x: use the correct implementation drm/nouveau/fifo/gf100-: protect channel preempt with subdev mutex drm/nouveau/ltc: protect clearing of comptags with mutex drm/nouveau/bios: require checksum to match for fast acpi shadow method drm/nouveau/kms: lvds panel strap moved again on maxwell ACPI / video: Add force_native quirk for HP Pavilion dv6 ACPI / video: Add force_native quirk for Dell XPS 17 L702X staging: comedi: ni_mio_common: fix E series ni_ai_insn_read() data staging: comedi: ni_mio_common: fix M Series ni_ai_insn_read() data mask thermal: hwmon: Properly report critical temperature in sysfs clk: bcm2835: Avoid overwriting the div info when disabling a pll_div clk timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion regulator: stw481x-vmmc: fix ages old enable error mmc: sdhci: Fix recovery from tuning timeout ath9k: Really fix LED polarity for some Mini PCI AR9220 MB92 cards. cfg80211/mac80211: fix BSS leaks when abandoning assoc attempts rtlwifi: Fix enter/exit power_save ssb: Fix error routine when fallback SPROM fails Linux 4.4.40 ppp: defer netns reference release for ppp channel driver core: fix race between creating/querying glue dir and its cleanup xfs: set AGI buffer type in xlog_recover_clear_agi_bucket arm/xen: Use alloc_percpu rather than __alloc_percpu xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing tpm xen: Remove bogus tpm_chip_unregister kernel/debug/debug_core.c: more properly delay for secondary CPUs kernel/watchdog: use nmi registers snapshot in hardlockup handler CIFS: Fix a possible memory corruption in push locks CIFS: Fix missing nls unload in smb2_reconnect() CIFS: Fix a possible memory corruption during reconnect ASoC: intel: Fix crash at suspend/resume without card registration dm space map metadata: fix 'struct sm_metadata' leak on failed create dm crypt: mark key as invalid until properly loaded dm flakey: return -EINVAL on interval bounds error in flakey_ctr() blk-mq: Do not invoke .queue_rq() for a stopped queue usb: gadget: composite: always set ep->mult to a sensible value exec: Ensure mm->user_ns contains the execed files fs: exec: apply CLOEXEC before changing dumpable task flags mm/vmscan.c: set correct defer count for shrinker loop: return proper error from loop_queue_rq() f2fs: set ->owner for debugfs status file's file_operations ext4: do not perform data journaling when data is encrypted ext4: return -ENOMEM instead of success ext4: reject inodes with negative size ext4: add sanity checking to count_overhead() ext4: fix in-superblock mount options processing ext4: use more strict checks for inodes_per_block on mount ext4: fix stack memory corruption with 64k block size ext4: fix mballoc breakage with 64k block size crypto: caam - fix AEAD givenc descriptors ptrace: Capture the ptracer's creds not PT_PTRACE_CAP mm: Add a user_ns owner to mm_struct and fix ptrace permission checks block_dev: don't test bdev->bd_contains when it is not stable btrfs: make file clone aware of fatal signals Btrfs: don't BUG() during drop snapshot Btrfs: fix memory leak in do_walk_down Btrfs: don't leak reloc root nodes on error Btrfs: return gracefully from balance if fs tree is corrupted Btrfs: bail out if block group has different mixed flag Btrfs: fix memory leak in reading btree blocks clk: ti: omap36xx: Work around sprz319 advisory 2.1 ALSA: hda: when comparing pin configurations, ignore assoc in addition to seq ALSA: hda - Gate the mic jack on HP Z1 Gen3 AiO ALSA: hda - fix headset-mic problem on a Dell laptop ALSA: hda - ignore the assoc and seq when comparing pin configurations ALSA: hda/ca0132 - Add quirk for Alienware 15 R2 2016 ALSA: hiface: Fix M2Tech hiFace driver sampling rate change ALSA: usb-audio: Add QuickCam Communicate Deluxe/S7500 to volume_control_quirks USB: UHCI: report non-PME wakeup signalling for Intel hardware usb: gadget: composite: correctly initialize ep->maxpacket usb: gadget: f_uac2: fix error handling at afunc_bind usb: hub: Fix auto-remount of safely removed or ejected USB-3 devices USB: cdc-acm: add device id for GW Instek AFG-125 USB: serial: kl5kusb105: fix open error path USB: serial: option: add dlink dwm-158 USB: serial: option: add support for Telit LE922A PIDs 0x1040, 0x1041 Btrfs: fix qgroup rescan worker initialization btrfs: store and load values of stripes_min/stripes_max in balance status item Btrfs: fix tree search logic when replaying directory entry deletes btrfs: limit async_work allocation and worker func duration ANDROID: trace: net: use %pK for kernel pointers ANDROID: android-base: Enable QUOTA related configs net: ipv4: Don't crash if passing a null sk to ip_rt_update_pmtu. net: inet: Support UID-based routing in IP protocols. Revert "net: ipv6: fix virtual tunneling build" net: core: add UID to flows, rules, and routes net: core: Add a UID field to struct sock. Revert "net: core: Support UID-based routing." Revert "net: core: Handle 'sk' being NULL in UID-based routing" Revert "ANDROID: net: fix 'const' warnings" Revert "ANDROID: net: fib: remove duplicate assignment" Revert "ANDROID: net: core: fix UID-based routing" UPSTREAM: efi/arm64: Don't apply MEMBLOCK_NOMAP to UEFI memory map mapping UPSTREAM: arm64: enable CONFIG_DEBUG_RODATA by default goldfish: enable CONFIG_INET_DIAG_DESTROY sched/walt: kill {min,max}_capacity sched: fix wrong truncation of walt_avg ANDROID: dm verity: add minimum prefetch size Linux 4.4.39 crypto: rsa - Add Makefile dependencies to fix parallel builds hotplug: Make register and unregister notifier API symmetric batman-adv: Check for alloc errors when preparing TT local data m68k: Fix ndelay() macro arm64: futex.h: Add missing PAN toggling can: peak: fix bad memory access and free sequence can: raw: raw_setsockopt: limit number of can_filter that can be set crypto: mcryptd - Check mcryptd algorithm compatibility perf/x86: Fix full width counter, counter overflow locking/rtmutex: Use READ_ONCE() in rt_mutex_owner() locking/rtmutex: Prevent dequeue vs. unlock race zram: restrict add/remove attributes to root only parisc: Fix TLB related boot crash on SMP machines parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm parisc: Purge TLB before setting PTE powerpc/eeh: Fix deadlock when PE frozen state can't be cleared Conflicts: arch/arm64/kernel/traps.c drivers/usb/dwc3/core.h drivers/usb/dwc3/ep0.c drivers/usb/gadget/function/f_fs.c drivers/usb/host/xhci-mem.c drivers/usb/host/xhci-ring.c drivers/usb/host/xhci.c drivers/video/fbdev/core/fbcmap.c include/trace/events/sched.h mm/vmscan.c Change-Id: I3faa0010ecb98972cd8e6470377a493b56d95f89 Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org> Signed-off-by: Runmin Wang <runminw@codeaurora.org>
| * Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidAlex Shi2016-12-20
| |\
| | * hotplug: Make register and unregister notifier API symmetricMichal Hocko2016-12-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 777c6e0daebb3fcefbbd6f620410a946b07ef6d0 upstream. Yu Zhao has noticed that __unregister_cpu_notifier only unregisters its notifiers when HOTPLUG_CPU=y while the registration might succeed even when HOTPLUG_CPU=n if MODULE is enabled. This means that e.g. zswap might keep a stale notifier on the list on the manual clean up during the pool tear down and thus corrupt the list. Resulting in the following [ 144.964346] BUG: unable to handle kernel paging request at ffff880658a2be78 [ 144.971337] IP: [<ffffffffa290b00b>] raw_notifier_chain_register+0x1b/0x40 <snipped> [ 145.122628] Call Trace: [ 145.125086] [<ffffffffa28e5cf8>] __register_cpu_notifier+0x18/0x20 [ 145.131350] [<ffffffffa2a5dd73>] zswap_pool_create+0x273/0x400 [ 145.137268] [<ffffffffa2a5e0fc>] __zswap_param_set+0x1fc/0x300 [ 145.143188] [<ffffffffa2944c1d>] ? trace_hardirqs_on+0xd/0x10 [ 145.149018] [<ffffffffa2908798>] ? kernel_param_lock+0x28/0x30 [ 145.154940] [<ffffffffa2a3e8cf>] ? __might_fault+0x4f/0xa0 [ 145.160511] [<ffffffffa2a5e237>] zswap_compressor_param_set+0x17/0x20 [ 145.167035] [<ffffffffa2908d3c>] param_attr_store+0x5c/0xb0 [ 145.172694] [<ffffffffa290848d>] module_attr_store+0x1d/0x30 [ 145.178443] [<ffffffffa2b2b41f>] sysfs_kf_write+0x4f/0x70 [ 145.183925] [<ffffffffa2b2a5b9>] kernfs_fop_write+0x149/0x180 [ 145.189761] [<ffffffffa2a99248>] __vfs_write+0x18/0x40 [ 145.194982] [<ffffffffa2a9a412>] vfs_write+0xb2/0x1a0 [ 145.200122] [<ffffffffa2a9a732>] SyS_write+0x52/0xa0 [ 145.205177] [<ffffffffa2ff4d97>] entry_SYSCALL_64_fastpath+0x12/0x17 This can be even triggered manually by changing /sys/module/zswap/parameters/compressor multiple times. Fix this issue by making unregister APIs symmetric to the register so there are no surprises. Fixes: 47e627bc8c9a ("[PATCH] hotplug: Allow modules to use the cpu hotplug notifiers even if !CONFIG_HOTPLUG_CPU") Reported-and-tested-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Streetman <ddstreet@ieee.org> Link: http://lkml.kernel.org/r/20161207135438.4310-1-mhocko@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | sched: add hook for platform-specific CPU power informationSteve Muckle2016-03-23
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To enable power-aware scheduling, provide a hook/infrastructure for platforms to communicate CPU power requirements for each supported CPU frequency. This information is then used to estimate the cost of running a task on a given CPU. Currently, an assumption is made that the task will be running by itself on the CPU. Given the current policy tries to spread tasks as much as possible this assumption should not be too far off. Change-Id: I19f1fa760a0d43222d2880f8aec0508c468b39bb Signed-off-by: Steve Muckle <smuckle@codeaurora.org> Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org> [joonwoop@codeaurora.org: return rq->capacity as power cost with sched_use_pelt=1. se.avg.runnable_avg_period is deprecated and power_cost() will be changed by subsequent change anyway./ Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
* / Move x86_64 idle notifiers to genericTodd Poynor2016-02-16
|/ | | | | | | | | Move the x86_64 idle notifiers originally by Andi Kleen and Venkatesh Pallipadi to generic. Change-Id: Idf29cda15be151f494ff245933c12462643388d5 Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Todd Poynor <toddpoynor@google.com>
* cpu: Remove try_get_online_cpus()Paul E. McKenney2015-10-07
| | | | | | | | | | Now that synchronize_sched_expedited() no longer uses it, there are no users of try_get_online_cpus() in mainline. This commit therefore removes it. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* include, lib: add __printf attributes to several function prototypesNicolas Iooss2015-07-17
| | | | | | | | | | | | | | | | | | | | | | Using __printf attributes helps to detect several format string issues at compile time (even though -Wformat-security is currently disabled in Makefile). For example it can detect when formatting a pointer as a number, like the issue fixed in commit a3fa71c40f18 ("wl18xx: show rx_frames_per_rates as an array as it really is"), or when the arguments do not match the format string, c.f. for example commit 5ce1aca81435 ("reiserfs: fix __RASSERT format string"). To prevent similar bugs in the future, add a __printf attribute to every function prototype which needs one in include/linux/ and lib/. These functions were mostly found by using gcc's -Wsuggest-attribute=format flag. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Felipe Balbi <balbi@ti.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpu: Provide smpboot_thread_init() on !CONFIG_SMP kernels as wellIngo Molnar2015-04-13
| | | | | | | | | | | | | | | | Now that we are using smpboot_thread_init() in init/main.c as well, provide it for !CONFIG_SMP as well. This addresses a !CONFIG_SMP build failure. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* cpu: Defer smpboot kthread unparking until CPU known to schedulerPaul E. McKenney2015-04-13
| | | | | | | | | | | | | | | | | | | | | | | | | Currently, smpboot_unpark_threads() is invoked before the incoming CPU has been added to the scheduler's runqueue structures. This might potentially cause the unparked kthread to run on the wrong CPU, since the correct CPU isn't fully set up yet. That causes a sporadic, hard to debug boot crash triggering on some systems, reported by Borislav Petkov, and bisected down to: 2a442c9c6453 ("x86: Use common outgoing-CPU-notification code") This patch places smpboot_unpark_threads() in a CPU hotplug notifier with priority set so that these kthreads are unparked just after the CPU has been added to the runqueues. Reported-and-tested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* rcu: Handle outgoing CPUs on exit from idle loopPaul E. McKenney2015-03-12
| | | | | | | | | | | | | This commit informs RCU of an outgoing CPU just before that CPU invokes arch_cpu_idle_dead() during its last pass through the idle loop (via a new CPU_DYING_IDLE notifier value). This change means that RCU need not deal with outgoing CPUs passing through the scheduler after informing RCU that they are no longer online. Note that removing the CPU from the rcu_node ->qsmaskinit bit masks is done at CPU_DYING_IDLE time, and orphaning callbacks is still done at CPU_DEAD time, the reason being that at CPU_DEAD time we have another CPU that can adopt them. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* smpboot: Add common code for notification from dying CPUPaul E. McKenney2015-03-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RCU ignores offlined CPUs, so they cannot safely run RCU read-side code. (They -can- use SRCU, but not RCU.) This means that any use of RCU during or after the call to arch_cpu_idle_dead(). Unfortunately, commit 2ed53c0d6cc99 added a complete() call, which will contain RCU read-side critical sections if there is a task waiting to be awakened. Which, as it turns out, there almost never is. In my qemu/KVM testing, the to-be-awakened task is not yet asleep more than 99.5% of the time. In current mainline, failure is even harder to reproduce, requiring a virtualized environment that delays the outgoing CPU by at least three jiffies between the time it exits its stop_machine() task at CPU_DYING time and the time it calls arch_cpu_idle_dead() from the idle loop. However, this problem really can occur, especially in virtualized environments, and therefore really does need to be fixed This suggests moving back to the polling loop, but using a much shorter wait, with gentle exponential backoff instead of the old 100-millisecond wait. Most of the time, the loop will exit without waiting at all, and almost all of the remaining uses will wait only five microseconds. If the outgoing CPU is preempted, a loop will wait one jiffy, then increase the wait by a factor of 11/10ths, rounding up. As before, there is a five-second timeout. This commit therefore provides common-code infrastructure to do the dying-to-surviving CPU handoff in a safe manner. This code also provides an indication at CPU-online of whether the CPU to be onlined previously timed out on offline. The new cpu_check_up_prepare() function returns -EBUSY if this CPU previously took more than five seconds to go offline, or -EAGAIN if it has not yet managed to go offline. The rationale for -EAGAIN is that it might still be preempted, so an additional wait might well find it correctly offlined. Architecture-specific code can decide how to handle these conditions. Systems in which CPUs take themselves completely offline might respond to an -EBUSY return as if it was a zero (success) return. Systems in which the surviving CPU must take some action might take it at this time, or might simply mark the other CPU as unusable. Note that architectures that take the easy way out and simply pass the -EBUSY and -EAGAIN upwards will change the sysfs API. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> [ paulmck: Fixed state machine for architectures that don't check earlier CPU-hotplug results as suggested by James Hogan. ]
* drivers: base: add cpu_device_create to support per-cpu devicesSudeep Holla2014-11-07
| | | | | | | | | | | | | | | | | | | | | This patch adds a new function to create per-cpu devices. This helps in: 1. reusing the device infrastructure to create any cpu related attributes and corresponding sysfs instead of creating and dealing with raw kobjects directly 2. retaining the legacy path(/sys/devices/system/cpu/..) to support existing sysfs ABI 3. avoiding to create links in the bus directory pointing to the device as there would be per-cpu instance of these devices with the same name since dev->bus is not populated to cpu_sysbus on purpose Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* rcu: Eliminate deadlock between CPU hotplug and expedited grace periodsPaul E. McKenney2014-09-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the expedited grace-period primitives do get_online_cpus(). This greatly simplifies their implementation, but means that calls to them holding locks that are acquired by CPU-hotplug notifiers (to say nothing of calls to these primitives from CPU-hotplug notifiers) can deadlock. But this is starting to become inconvenient, as can be seen here: https://lkml.org/lkml/2014/8/5/754. The problem in this case is that some developers need to acquire a mutex from a CPU-hotplug notifier, but also need to hold it across a synchronize_rcu_expedited(). As noted above, this currently results in deadlock. This commit avoids the deadlock and retains the simplicity by creating a try_get_online_cpus(), which returns false if the get_online_cpus() reference count could not immediately be incremented. If a call to try_get_online_cpus() returns true, the expedited primitives operate as before. If a call returns false, the expedited primitives fall back to normal grace-period operations. This falling back of course results in increased grace-period latency, but only during times when CPU hotplug operations are actually in flight. The effect should therefore be negligible during normal operation. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Tested-by: Lan Tianyu <tianyu.lan@intel.com>
* idle: remove cpu_idle() forward declarationsGeert Uytterhoeven2014-06-06
| | | | | | | | | | | | After all architectures were converted to the generic idle framework, commit d190e8195b90 ("idle: Remove GENERIC_IDLE_LOOP config switch") removed the last caller of cpu_idle(). The forward declarations in header files were forgotten. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'cpu-hotplug-3.15-rc1' of ↵Linus Torvalds2014-04-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull CPU hotplug notifiers registration fixes from Rafael Wysocki: "The purpose of this single series of commits from Srivatsa S Bhat (with a small piece from Gautham R Shenoy) touching multiple subsystems that use CPU hotplug notifiers is to provide a way to register them that will not lead to deadlocks with CPU online/offline operations as described in the changelog of commit 93ae4f978ca7f ("CPU hotplug: Provide lockless versions of callback registration functions"). The first three commits in the series introduce the API and document it and the rest simply goes through the users of CPU hotplug notifiers and converts them to using the new method" * tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) net/iucv/iucv.c: Fix CPU hotplug callback registration net/core/flow.c: Fix CPU hotplug callback registration mm, zswap: Fix CPU hotplug callback registration mm, vmstat: Fix CPU hotplug callback registration profile: Fix CPU hotplug callback registration trace, ring-buffer: Fix CPU hotplug callback registration xen, balloon: Fix CPU hotplug callback registration hwmon, via-cputemp: Fix CPU hotplug callback registration hwmon, coretemp: Fix CPU hotplug callback registration thermal, x86-pkg-temp: Fix CPU hotplug callback registration octeon, watchdog: Fix CPU hotplug callback registration oprofile, nmi-timer: Fix CPU hotplug callback registration intel-idle: Fix CPU hotplug callback registration clocksource, dummy-timer: Fix CPU hotplug callback registration drivers/base/topology.c: Fix CPU hotplug callback registration acpi-cpufreq: Fix CPU hotplug callback registration zsmalloc: Fix CPU hotplug callback registration scsi, fcoe: Fix CPU hotplug callback registration scsi, bnx2fc: Fix CPU hotplug callback registration scsi, bnx2i: Fix CPU hotplug callback registration ...
| * CPU hotplug: Provide lockless versions of callback registration functionsSrivatsa S. Bhat2014-03-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following method of CPU hotplug callback registration is not safe due to the possibility of an ABBA deadlock involving the cpu_add_remove_lock and the cpu_hotplug.lock. get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); The deadlock is shown below: CPU 0 CPU 1 ----- ----- Acquire cpu_hotplug.lock [via get_online_cpus()] CPU online/offline operation takes cpu_add_remove_lock [via cpu_maps_update_begin()] Try to acquire cpu_add_remove_lock [via register_cpu_notifier()] CPU online/offline operation tries to acquire cpu_hotplug.lock [via cpu_hotplug_begin()] *** DEADLOCK! *** The problem here is that callback registration takes the locks in one order whereas the CPU hotplug operations take the same locks in the opposite order. To avoid this issue and to provide a race-free method to register CPU hotplug callbacks (along with initialization of already online CPUs), introduce new variants of the callback registration APIs that simply register the callbacks without holding the cpu_add_remove_lock during the registration. That way, we can avoid the ABBA scenario. However, we will need to hold the cpu_add_remove_lock throughout the entire critical section, to protect updates to the callback/notifier chain. This can be achieved by writing the callback registration code as follows: cpu_maps_update_begin(); [ or cpu_notifier_register_begin(); see below ] for_each_online_cpu(cpu) init_cpu(cpu); /* This doesn't take the cpu_add_remove_lock */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_maps_update_done(); [ or cpu_notifier_register_done(); see below ] Note that we can't use get_online_cpus() here instead of cpu_maps_update_begin() because the cpu_hotplug.lock is dropped during the invocation of CPU_POST_DEAD notifiers, and hence get_online_cpus() cannot provide the necessary synchronization to protect the callback/notifier chains against concurrent reads and writes. On the other hand, since the cpu_add_remove_lock protects the entire hotplug operation (including CPU_POST_DEAD), we can use cpu_maps_update_begin/done() to guarantee proper synchronization. Also, since cpu_maps_update_begin/done() is like a super-set of get/put_online_cpus(), the former naturally protects the critical sections from concurrent hotplug operations. Since the names cpu_maps_update_begin/done() don't make much sense in CPU hotplug callback registration scenarios, we'll introduce new APIs named cpu_notifier_register_begin/done() and map them to cpu_maps_update_begin/done(). In summary, introduce the lockless variants of un/register_cpu_notifier() and also export the cpu_notifier_register_begin/done() APIs for use by modules. This way, we provide a race-free way to register hotplug callbacks as well as perform initialization for the CPUs that are already online. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | x86: align x86 arch with generic CPU modalias handlingArd Biesheuvel2014-02-18
|/ | | | | | | | | | | | | | The x86 CPU feature modalias handling existed before it was reimplemented generically. This patch aligns the x86 handling so that it (a) reuses some more code that is now generic; (b) uses the generic format for the modalias module metadata entry, i.e., it now uses 'cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:,XXXX,YYYY' instead of the 'x86cpu:vendor:VVVV:family:FFFF:model:MMMM:feature:,XXXX,YYYY' that was used before. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'pm+acpi-3.13-rc1' of ↵Linus Torvalds2013-11-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael J Wysocki: - New power capping framework and the the Intel Running Average Power Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan. - Addition of the in-kernel switching feature to the arm_big_little cpufreq driver from Viresh Kumar and Nicolas Pitre. - cpufreq support for iMac G5 from Aaro Koskinen. - Baytrail processors support for intel_pstate from Dirk Brandewie. - cpufreq support for Midway/ECX-2000 from Mark Langsdorf. - ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha. - ACPI power management support for the I2C and SPI bus types from Mika Westerberg and Lv Zheng. - cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat, Stratos Karafotis, Xiaoguang Chen, Lan Tianyu. - cpufreq drivers updates (mostly fixes and cleanups) from Viresh Kumar, Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz Majewski, Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev. - intel_pstate updates from Dirk Brandewie and Adrian Huang. - ACPICA update to version 20130927 includig fixes and cleanups and some reduction of divergences between the ACPICA code in the kernel and ACPICA upstream in order to improve the automatic ACPICA patch generation process. From Bob Moore, Lv Zheng, Tomasz Nowicki, Naresh Bhat, Bjorn Helgaas, David E Box. - ACPI IPMI driver fixes and cleanups from Lv Zheng. - ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani, Zhang Yanfei, Rafael J Wysocki. - Conversion of the ACPI AC driver to the platform bus type and multiple driver fixes and cleanups related to ACPI from Zhang Rui. - ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu, Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki. - Fixes and cleanups and new blacklist entries related to the ACPI video support from Aaron Lu, Felipe Contreras, Lennart Poettering, Kirill Tkhai. - cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi. - cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han, Bartlomiej Zolnierkiewicz, Prarit Bhargava. - devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe. - Operation Performance Points (OPP) core updates from Nishanth Menon. - Runtime power management core fix from Rafael J Wysocki and update from Ulf Hansson. - Hibernation fixes from Aaron Lu and Rafael J Wysocki. - Device suspend/resume lockup detection mechanism from Benoit Goby. - Removal of unused proc directories created for various ACPI drivers from Lan Tianyu. - ACPI LPSS driver fix and new device IDs for the ACPI platform scan handler from Heikki Krogerus and Jarkko Nikula. - New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa. - Assorted fixes and cleanups related to ACPI from Andy Shevchenko, Al Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter, Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause, Liu Chuansheng. - Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding, Jean-Christophe Plagniol-Villard. * tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (386 commits) cpufreq: conservative: fix requested_freq reduction issue ACPI / hotplug: Consolidate deferred execution of ACPI hotplug routines PM / runtime: Use pm_runtime_put_sync() in __device_release_driver() ACPI / event: remove unneeded NULL pointer check Revert "ACPI / video: Ignore BIOS initial backlight value for HP 250 G1" ACPI / video: Quirk initial backlight level 0 ACPI / video: Fix initial level validity test intel_pstate: skip the driver if ACPI has power mgmt option PM / hibernate: Avoid overflow in hibernate_preallocate_memory() ACPI / hotplug: Do not execute "insert in progress" _OST ACPI / hotplug: Carry out PCI root eject directly ACPI / hotplug: Merge device hot-removal routines ACPI / hotplug: Make acpi_bus_hot_remove_device() internal ACPI / hotplug: Simplify device ejection routines ACPI / hotplug: Fix handle_root_bridge_removal() ACPI / hotplug: Refuse to hot-remove all objects with disabled hotplug ACPI / scan: Start matching drivers after trying scan handlers ACPI: Remove acpi_pci_slot_init() headers from internal.h ACPI / blacklist: fix name of ThinkPad Edge E530 PowerCap: Fix build error with option -Werror=format-security ... Conflicts: arch/arm/mach-omap2/opp.c drivers/Kconfig drivers/spi/spi.c
| * hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock()Toshi Kani2013-09-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpu_hotplug_driver_lock() serializes CPU online/offline operations when ARCH_CPU_PROBE_RELEASE is set. This lock interface is no longer necessary with the following reason: - lock_device_hotplug() now protects CPU online/offline operations, including the probe & release interfaces enabled by ARCH_CPU_PROBE_RELEASE. The use of cpu_hotplug_driver_lock() is redundant. - cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE is defined, which is misleading and is only enabled on powerpc. This patch removes the cpu_hotplug_driver_lock() interface. As a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu probe & release interface as intended. There is no functional change in this patch. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | of: Make cpu node handling more portable.David Miller2013-10-15
|/ | | | | | | | | | | | | | | | | Use for_each_node_by_type() to iterate all cpu nodes in the system. Provide and overridable function arch_find_n_match_cpu_physical_id, which sees if the given device node matches 'cpu' and if so sets '*thread' when non-NULL to the cpu thread number within the core. The default implementation behaves the same as the existing code. Add a sparc64 implementation. Signed-off-by: David S. Miller <davem@davemloft.net> Tested-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>
* Merge branch 'pm-cpufreq'Rafael J. Wysocki2013-08-27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-cpufreq: (60 commits) cpufreq: pmac32-cpufreq: remove device tree parsing for cpu nodes cpufreq: pmac64-cpufreq: remove device tree parsing for cpu nodes cpufreq: maple-cpufreq: remove device tree parsing for cpu nodes cpufreq: arm_big_little: remove device tree parsing for cpu nodes cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes cpufreq: spear-cpufreq: remove device tree parsing for cpu nodes cpufreq: highbank-cpufreq: remove device tree parsing for cpu nodes cpufreq: cpufreq-cpu0: remove device tree parsing for cpu nodes cpufreq: imx6q-cpufreq: remove device tree parsing for cpu nodes drivers/bus: arm-cci: avoid parsing DT for cpu device nodes ARM: mvebu: remove device tree parsing for cpu nodes ARM: topology: remove hwid/MPIDR dependency from cpu_capacity of/device: add helper to get cpu device node from logical cpu index driver/core: cpu: initialize of_node in cpu's device struture ARM: DT/kernel: define ARM specific arch_match_cpu_phys_id of: move of_get_cpu_node implementation to DT core library powerpc: refactor of_get_cpu_node to support other architectures openrisc: remove undefined of_get_cpu_node declaration microblaze: remove undefined of_get_cpu_node declaration cpufreq: fix bad unlock balance on !CONFIG_SMP ...
| * of: move of_get_cpu_node implementation to DT core librarySudeep KarkadaNagesha2013-08-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves the generalized implementation of of_get_cpu_node from PowerPC to DT core library, thereby adding support for retrieving cpu node for a given logical cpu index on any architecture. The CPU subsystem can now use this function to assign of_node in the cpu device while registering CPUs. It is recommended to use these helper function only in pre-SMP/early initialisation stages to retrieve CPU device node pointers in logical ordering. Once the cpu devices are registered, it can be retrieved easily from cpu device of_node which avoids unnecessary parsing and matching. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Grant Likely <grant.likely@linaro.org> Acked-by: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
* | ACPI / processor: Acquire writer lock to update CPU mapsToshi Kani2013-08-13
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPU system maps are protected with reader/writer locks. The reader lock, get_online_cpus(), assures that the maps are not updated while holding the lock. The writer lock, cpu_hotplug_begin(), is used to udpate the cpu maps along with cpu_maps_update_begin(). However, the ACPI processor handler updates the cpu maps without holding the the writer lock. acpi_map_lsapic() is called from acpi_processor_hotadd_init() to update cpu_possible_mask and cpu_present_mask. acpi_unmap_lsapic() is called from acpi_processor_remove() to update cpu_possible_mask. Currently, they are either unprotected or protected with the reader lock, which is not correct. For example, the get_online_cpus() below is supposed to assure that cpu_possible_mask is not changed while the code is iterating with for_each_possible_cpu(). get_online_cpus(); for_each_possible_cpu(cpu) { : } put_online_cpus(); However, this lock has no protection with CPU hotplug since the ACPI processor handler does not use the writer lock when it updates cpu_possible_mask. The reader lock does not serialize within the readers. This patch protects them with the writer lock with cpu_hotplug_begin() along with cpu_maps_update_begin(), which must be held before calling cpu_hotplug_begin(). It also protects arch_register_cpu() / arch_unregister_cpu(), which creates / deletes a sysfs cpu device interface. For this purpose it changes cpu_hotplug_begin() and cpu_hotplug_done() to global and exports them in cpu.h. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* kernel: delete __cpuinit usage from all core kernel filesPaul Gortmaker2013-07-14
| | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the uses of the __cpuinit macros from C files in the core kernel directories (kernel, init, lib, mm, and include) that don't really have a specific maintainer. [1] https://lkml.org/lkml/2013/5/20/589 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-07-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "The usual stuff from trivial tree" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits) treewide: relase -> release Documentation/cgroups/memory.txt: fix stat file documentation sysctl/net.txt: delete reference to obsolete 2.4.x kernel spinlock_api_smp.h: fix preprocessor comments treewide: Fix typo in printk doc: device tree: clarify stuff in usage-model.txt. open firmware: "/aliasas" -> "/aliases" md: bcache: Fixed a typo with the word 'arithmetic' irq/generic-chip: fix a few kernel-doc entries frv: Convert use of typedef ctl_table to struct ctl_table sgi: xpc: Convert use of typedef ctl_table to struct ctl_table doc: clk: Fix incorrect wording Documentation/arm/IXP4xx fix a typo Documentation/networking/ieee802154 fix a typo Documentation/DocBook/media/v4l fix a typo Documentation/video4linux/si476x.txt fix a typo Documentation/virtual/kvm/api.txt fix a typo Documentation/early-userspace/README fix a typo Documentation/video4linux/soc-camera.txt fix a typo lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment ...
| * include/linux/cpu.h: Update comments to reflect realityRobert P. J. Day2013-05-28
| | | | | | | | | | | | | | | | | | | | Two minor changes to comments: * Remove reference to drivers/base/sys.c, removed in 0a962657. * CPUs are now exported by sysfs via devices/system/cpu. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | CPU hotplug: provide a generic helper to disable/enable CPU hotplugSrivatsa S. Bhat2013-06-12
|/ | | | | | | | | | | | | | | | | | | | | | | | There are instances in the kernel where we would like to disable CPU hotplug (from sysfs) during some important operation. Today the freezer code depends on this and the code to do it was kinda tailor-made for that. Restructure the code and make it generic enough to be useful for other usecases too. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idle: Implement generic idle functionThomas Gleixner2013-04-08
| | | | | | | | | | | | | | | | | | | | All idle functions in arch/* are more or less the same, plus minus a few bugs and extra instrumentation, tickless support and other optional items. Implement a generic idle function which resembles the functionality found in arch/. Provide weak arch_cpu_idle_* functions which can be overridden by the architecture code if needed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.646635455@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* idle: Provide a generic entry point for the idle codeThomas Gleixner2013-04-08
| | | | | | | | | | | | | | | For now this calls cpu_idle(), but in the long run we want to move the cpu bringup code to the core and therefor we add a state argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.583190032@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* workqueue: perform cpu down operations from low priority cpu_notifier()Tejun Heo2012-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, all workqueue cpu hotplug operations run off CPU_PRI_WORKQUEUE which is higher than normal notifiers. This is to ensure that workqueue is up and running while bringing up a CPU before other notifiers try to use workqueue on the CPU. Per-cpu workqueues are supposed to remain working and bound to the CPU for normal CPU_DOWN_PREPARE notifiers. This holds mostly true even with workqueue offlining running with higher priority because workqueue CPU_DOWN_PREPARE only creates a bound trustee thread which runs the per-cpu workqueue without concurrency management without explicitly detaching the existing workers. However, if the trustee needs to create new workers, it creates unbound workers which may wander off to other CPUs while CPU_DOWN_PREPARE notifiers are in progress. Furthermore, if the CPU down is cancelled, the per-CPU workqueue may end up with workers which aren't bound to the CPU. While reliably reproducible with a convoluted artificial test-case involving scheduling and flushing CPU burning work items from CPU down notifiers, this isn't very likely to happen in the wild, and, even when it happens, the effects are likely to be hidden by the following successful CPU down. Fix it by using different priorities for up and down notifiers - high priority for up operations and low priority for down operations. Workqueue cpu hotplug operations will soon go through further cleanup. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
* cpu: introduce clear_tasks_mm_cpumask() helperAnton Vorontsov2012-05-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many architectures clear tasks' mm_cpumask like this: read_lock(&tasklist_lock); for_each_process(p) { if (p->mm) cpumask_clear_cpu(cpu, mm_cpumask(p->mm)); } read_unlock(&tasklist_lock); Depending on the context, the code above may have several problems, such as: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. This patch implements a small helper function that does things correctly, i.e.: 1. We take the task's lock while whe handle its mm (we can't use get_task_mm()/mmput() pair as mmput() might sleep); 2. To catch exited main thread case, we use find_lock_task_mm(), which walks up all threads and returns an appropriate task (with task lock held). Also, Per Peter Zijlstra's idea, now we don't grab tasklist_lock in the new helper, instead we take the rcu read lock. We can do this because the function is called after the cpu is taken down and marked offline, so no new tasks will get this cpu set in their mm mask. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: Remove stale power aware scheduling remnants and dysfunctional knobsPeter Zijlstra2012-05-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's been broken forever (i.e. it's not scheduling in a power aware fashion), as reported by Suresh and others sending patches, and nobody cares enough to fix it properly ... so remove it to make space free for something better. There's various problems with the code as it stands today, first and foremost the user interface which is bound to topology levels and has multiple values per level. This results in a state explosion which the administrator or distro needs to master and almost nobody does. Furthermore large configuration state spaces aren't good, it means the thing doesn't just work right because it's either under so many impossibe to meet constraints, or even if there's an achievable state workloads have to be aware of it precisely and can never meet it for dynamic workloads. So pushing this kind of decision to user-space was a bad idea even with a single knob - it's exponentially worse with knobs on every node of the topology. There is a proposal to replace the user interface with a single 3 state knob: sched_balance_policy := { performance, power, auto } where 'auto' would be the preferred default which looks at things like Battery/AC mode and possible cpufreq state or whatever the hw exposes to show us power use expectations - but there's been no progress on it in the past many months. Aside from that, the actual implementation of the various knobs is known to be broken. There have been sporadic attempts at fixing things but these always stop short of reaching a mergable state. Therefore this wholesale removal with the hopes of spurring people who care to come forward once again and work on a coherent replacement. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge tag 'device-for-3.4' of ↵Linus Torvalds2012-03-24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull <linux/device.h> avoidance patches from Paul Gortmaker: "Nearly every subsystem has some kind of header with a proto like: void foo(struct device *dev); and yet there is no reason for most of these guys to care about the sub fields within the device struct. This allows us to significantly reduce the scope of headers including headers. For this instance, a reduction of about 40% is achieved by replacing the include with the simple fact that the device is some kind of a struct. Unlike the much larger module.h cleanup, this one is simply two commits. One to fix the implicit <linux/device.h> users, and then one to delete the device.h includes from the linux/include/ dir wherever possible." * tag 'device-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: device.h: audit and cleanup users in main include dir device.h: cleanup users outside of linux/include (C files)
| * device.h: audit and cleanup users in main include dirPaul Gortmaker2012-03-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The <linux/device.h> header includes a lot of stuff, and it in turn gets a lot of use just for the basic "struct device" which appears so often. Clean up the users as follows: 1) For those headers only needing "struct device" as a pointer in fcn args, replace the include with exactly that. 2) For headers not really using anything from device.h, simply delete the include altogether. 3) For headers relying on getting device.h implicitly before being included themselves, now explicitly include device.h 4) For files in which doing #1 or #2 uncovers an implicit dependency on some other header, fix by explicitly adding the required header(s). Any C files that were implicitly relying on device.h to be present have already been dealt with in advance. Total removals from #1 and #2: 51. Total additions coming from #3: 9. Total other implicit dependencies from #4: 7. As of 3.3-rc1, there were 110, so a net removal of 42 gives about a 38% reduction in device.h presence in include/* Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | CPU: Introduce ARCH_HAS_CPU_AUTOPROBE and X86 partsThomas Renninger2012-01-26
|/ | | | | | | | | | | | | | | | | | | | | | | | This patch is based on Andi Kleen's work: Implement autoprobing/loading of modules serving CPU specific features (x86cpu autoloading). And Kay Siever's work to get rid of sysdev cpu structures and making use of struct device instead. Before, the cpuid driver had to be loaded to get the x86cpu autoloading feature. With this patch autoloading works through the /sys/devices/system/cpu object Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Jones <davej@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Huang Ying <ying.huang@intel.com> Cc: Len Brown <lenb@kernel.org> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'driver-core-next' of ↵Linus Torvalds2012-01-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core * 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (73 commits) arm: fix up some samsung merge sysdev conversion problems firmware: Fix an oops on reading fw_priv->fw in sysfs loading file Drivers:hv: Fix a bug in vmbus_driver_unregister() driver core: remove __must_check from device_create_file debugfs: add missing #ifdef HAS_IOMEM arm: time.h: remove device.h #include driver-core: remove sysdev.h usage. clockevents: remove sysdev.h arm: convert sysdev_class to a regular subsystem arm: leds: convert sysdev_class to a regular subsystem kobject: remove kset_find_obj_hinted() m86k: gpio - convert sysdev_class to a regular subsystem mips: txx9_sram - convert sysdev_class to a regular subsystem mips: 7segled - convert sysdev_class to a regular subsystem sh: dma - convert sysdev_class to a regular subsystem sh: intc - convert sysdev_class to a regular subsystem power: suspend - convert sysdev_class to a regular subsystem power: qe_ic - convert sysdev_class to a regular subsystem power: cmm - convert sysdev_class to a regular subsystem s390: time - convert sysdev_class to a regular subsystem ... Fix up conflicts with 'struct sysdev' removal from various platform drivers that got changed: - arch/arm/mach-exynos/cpu.c - arch/arm/mach-exynos/irq-eint.c - arch/arm/mach-s3c64xx/common.c - arch/arm/mach-s3c64xx/cpu.c - arch/arm/mach-s5p64x0/cpu.c - arch/arm/mach-s5pv210/common.c - arch/arm/plat-samsung/include/plat/cpu.h - arch/powerpc/kernel/sysfs.c and fix up cpu_is_hotpluggable() as per Greg in include/linux/cpu.h
| * cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystemKay Sievers2011-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem and converts the devices to regular devices. The sysdev drivers are implemented as subsystem interfaces now. After all sysdev classes are ported to regular driver core entities, the sysdev implementation will be entirely removed from the kernel. Userspace relies on events and generic sysfs subsystem infrastructure from sysdev devices, which are made available with this conversion. Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@amd64.org> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Len Brown <lenb@kernel.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | driver-core/cpu: Expose hotpluggability to the rest of the kernelJosh Triplett2011-12-11
|/ | | | | | | | | | | | | | | | | | When architectures register CPUs, they indicate whether the CPU allows hotplugging; notably, x86 and ARM don't allow hotplugging CPU 0. Userspace can easily query the hotpluggability of a CPU via sysfs; however, the kernel has no convenient way of accessing that property in an architecture-independent way. While the kernel can simply try it and see, some code needs to distinguish between "hotplug failed" and "hotplug has no hope of working on this CPU"; for example, rcutorture's CPU hotplug tests want to avoid drowning out real hotplug failures with expected failures. Expose this property via a new cpu_is_hotpluggable function, so that the rest of the kernel can access it in an architecture-independent way. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* PM / Sleep: Remove unused symbol 'suspend_cpu_hotplug'Srivatsa S. Bhat2011-11-04
| | | | | | | | | | Remove the suspend_cpu_hotplug declaration, which doesn't correspond to an existing variable. [rjw: Added the changelog.] Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* notifiers: cpu: move cpu notifiers into cpu.hAmerigo Wang2011-07-25
| | | | | | | | | | | | | | | | | | | | | | | | We presently define all kinds of notifiers in notifier.h. This is not necessary at all, since different subsystems use different notifiers, they are almost non-related with each other. This can also save much build time. Suppose I add a new netdevice event, really I don't have to recompile all the source, just network related. Without this patch, all the source will be recompiled. I move the notify events near to their subsystem notifier registers, so that they can be found more easily. This patch: It is not necessary to share the same notifier.h. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* driver core: prune docs about device_interfaceBrandon Philips2010-11-10
| | | | | | | | drivers/base/intf.c was removed before the beginning of (git) time but its Documentation stuck around. Remove it. Signed-off-by: Brandon Philips <brandon@ifup.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* workqueue: reimplement CPU hotplugging support using trusteeTejun Heo2010-06-29
| | | | | | | | | | | | | | | | | | | | | | | | Reimplement CPU hotplugging support using trustee thread. On CPU down, a trustee thread is created and each step of CPU down is executed by the trustee and workqueue_cpu_callback() simply drives and waits for trustee state transitions. CPU down operation no longer waits for works to be drained but trustee sticks around till all pending works have been completed. If CPU is brought back up while works are still draining, workqueue_cpu_callback() tells trustee to step down and tell workers to rebind to the cpu. As it's difficult to tell whether cwqs are empty if it's freezing or frozen, trustee doesn't consider draining to be complete while a gcwq is freezing or frozen (tracked by new GCWQ_FREEZING flag). Also, workers which get unbound from their cpu are marked with WORKER_ROGUE. Trustee based implementation doesn't bring any new feature at this point but it will be used to manage worker pool when dynamic shared worker pool is implemented. Signed-off-by: Tejun Heo <tj@kernel.org>
* sched: adjust when cpu_active and cpuset configurations are updated during ↵Tejun Heo2010-06-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
* sched: define and use CPU_PRI_* enums for cpu notifier prioritiesTejun Heo2010-06-08
| | | | | | | | | | | | Instead of hardcoding priority 10 and 20 in sched and perf, collect them into CPU_PRI_* enums. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
* powerpc/pseries: Serialize cpu hotplug operations during deactivate Vs ↵Gautham R Shenoy2009-12-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | deallocate Currently the cpu-allocation/deallocation process comprises of two steps: - Set the indicators and to update the device tree with DLPAR node information. - Online/offline the allocated/deallocated CPU. This is achieved by writing to the sysfs tunables "probe" during allocation and "release" during deallocation. At the sametime, the userspace can independently online/offline the CPUs of the system using the sysfs tunable "online". It is quite possible that when a userspace tool offlines a CPU for the purpose of deallocation and is in the process of updating the device tree, some other userspace tool could bring the CPU back online by writing to the "online" sysfs tunable thereby causing the deallocate process to fail. The solution to this is to serialize writes to the "probe/release" sysfs tunable with the writes to the "online" sysfs tunable. This patch employs a mutex to provide this serialization, which is a no-op on all architectures except PPC_PSERIES Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* sysfs/cpu: Add probe/release filesNathan Fontenot2009-12-09
| | | | | | | | | | | | | | | | | | | | | | | Version 3 of this patch is updated with documentation added to Documentation/ABI. There are no changes to any of the C code from v2 of the patch. In order to support kernel DLPAR of CPU resources we need to provide an interface to add (probe) and remove (release) the resource from the system. This patch Creates new generic probe and release sysfs files to facilitate cpu probe/release. The probe/release interface provides for allowing each arch to supply their own routines for implementing the backend of adding and removing cpus to/from the system. This also creates the powerpc specific stubs to handle the arch callouts from writes to the sysfs files. The creation and use of these files is regulated by the CONFIG_ARCH_CPU_PROBE_RELEASE option so that only architectures that need the capability will have the files created. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* cpu hotplug: Introduce cpu_notifier() to handle !HOTPLUG_CPU casePaul E. McKenney2009-08-15
| | | | | | | | | | | | | | | | | | | | | | | This patch introduces a new cpu_notifier() API that is similar to hotcpu_notifier(), but which also notifies of CPUs coming online during boot in the !HOTPLUG_CPU case. Reported-by: Ingo Molnar <mingo@elte.hu> Reported-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Tested-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: josht@linux.vnet.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: benh@kernel.crashing.org LKML-Reference: <12503552312611-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* mm/init: cpu_hotplug_init() must be initialized before SLABLinus Torvalds2009-06-22
| | | | | | | | | | | | | | | | | | SLAB uses get/put_online_cpus() which use a mutex which is itself only initialized when cpu_hotplug_init() is called. Currently we hang suring boot in SLAB due to doing that too late. Reported by James Bottomley and Sachin Sant (and possibly others). Debugged by Benjamin Herrenschmidt. This just removes the dynamic initialization of the data structures, and replaces it with a static one, avoiding this dependency entirely, and removing one unnecessary special initcall. Tested-by: Sachin Sant <sachinp@in.ibm.com> Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpu hotplug: remove unused cpuhotplug_mutex_lock()Lai Jiangshan2009-04-02
| | | | | | | | | | | cpuhotplug_mutex_lock() is not used, remove it. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>