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178 commits

Author SHA1 Message Date
Runmin Wang
9cc5c789d9 Merge remote-tracking branch 'msm4.4/tmp-da9a92f' into msm-4.4
* origin/tmp-da9a92f:
  arm64: kaslr: increase randomization granularity
  arm64: relocatable: deal with physically misaligned kernel images
  arm64: don't map TEXT_OFFSET bytes below the kernel if we can avoid it
  arm64: kernel: replace early 64-bit literal loads with move-immediates
  arm64: introduce mov_q macro to move a constant into a 64-bit register
  arm64: kernel: perform relocation processing from ID map
  arm64: kernel: use literal for relocated address of __secondary_switched
  arm64: kernel: don't export local symbols from head.S
  arm64: simplify kernel segment mapping granularity
  arm64: cover the .head.text section in the .text segment mapping
  arm64: move early boot code to the .init segment
  arm64: use 'segment' rather than 'chunk' to describe mapped kernel regions
  arm64: mm: Mark .rodata as RO
  Linux 4.4.16
  ovl: verify upper dentry before unlink and rename
  drm/i915: Revert DisplayPort fast link training feature
  tmpfs: fix regression hang in fallocate undo
  tmpfs: don't undo fallocate past its last page
  crypto: qat - make qat_asym_algs.o depend on asn1 headers
  xen/acpi: allow xen-acpi-processor driver to load on Xen 4.7
  File names with trailing period or space need special case conversion
  cifs: dynamic allocation of ntlmssp blob
  Fix reconnect to not defer smb3 session reconnect long after socket reconnect
  53c700: fix BUG on untagged commands
  s390: fix test_fp_ctl inline assembly contraints
  scsi: fix race between simultaneous decrements of ->host_failed
  ovl: verify upper dentry in ovl_remove_and_whiteout()
  ovl: Copy up underlying inode's ->i_mode to overlay inode
  ARM: mvebu: fix HW I/O coherency related deadlocks
  ARM: dts: armada-38x: fix MBUS_ID for crypto SRAM on Armada 385 Linksys
  ARM: sunxi/dt: make the CHIP inherit from allwinner,sun5i-a13
  ALSA: hda: add AMD Stoney PCI ID with proper driver caps
  ALSA: hda - fix use-after-free after module unload
  ALSA: ctl: Stop notification after disconnection
  ALSA: pcm: Free chmap at PCM free callback, too
  ALSA: hda/realtek - add new pin definition in alc225 pin quirk table
  ALSA: hda - fix read before array start
  ALSA: hda - Add PCI ID for Kabylake-H
  ALSA: hda/realtek: Add Lenovo L460 to docking unit fixup
  ALSA: timer: Fix negative queue usage by racy accesses
  ALSA: echoaudio: Fix memory allocation
  ALSA: au88x0: Fix calculation in vortex_wtdma_bufshift()
  ALSA: hda / realtek - add two more Thinkpad IDs (5050,5053) for tpt460 fixup
  ALSA: hda - Fix the headset mic jack detection on Dell machine
  ALSA: dummy: Fix a use-after-free at closing
  hwmon: (dell-smm) Cache fan_type() calls and change fan detection
  hwmon: (dell-smm) Disallow fan_type() calls on broken machines
  hwmon: (dell-smm) Restrict fan control and serial number to CAP_SYS_ADMIN by default
  tty/vt/keyboard: fix OOB access in do_compute_shiftstate()
  tty: vt: Fix soft lockup in fbcon cursor blink timer.
  iio:ad7266: Fix probe deferral for vref
  iio:ad7266: Fix support for optional regulators
  iio:ad7266: Fix broken regulator error handling
  iio: accel: kxsd9: fix the usage of spi_w8r8()
  staging: iio: accel: fix error check
  iio: hudmidity: hdc100x: fix incorrect shifting and scaling
  iio: humidity: hdc100x: fix IIO_TEMP channel reporting
  iio: humidity: hdc100x: correct humidity integration time mask
  iio: proximity: as3935: fix buffer stack trashing
  iio: proximity: as3935: remove triggered buffer processing
  iio: proximity: as3935: correct IIO_CHAN_INFO_RAW output
  iio: light apds9960: Add the missing dev.parent
  iio:st_pressure: fix sampling gains (bring inline with ABI)
  iio: Fix error handling in iio_trigger_attach_poll_func
  xen/balloon: Fix declared-but-not-defined warning
  perf/x86: Fix undefined shift on 32-bit kernels
  memory: omap-gpmc: Fix omap gpmc EXTRADELAY timing
  drm/vmwgfx: Fix error paths when mapping framebuffer
  drm/vmwgfx: Delay pinning fbdev framebuffer until after mode set
  drm/vmwgfx: Check pin count before attempting to move a buffer
  drm/vmwgfx: Work around mode set failure in 2D VMs
  drm/vmwgfx: Add an option to change assumed FB bpp
  drm/ttm: Make ttm_bo_mem_compat available
  drm: atmel-hlcdc: actually disable scaling when no scaling is required
  drm: make drm_atomic_set_mode_prop_for_crtc() more reliable
  drm: add missing drm_mode_set_crtcinfo call
  drm/i915: Update CDCLK_FREQ register on BDW after changing cdclk frequency
  drm/i915: Update ifdeffery for mutex->owner
  drm/i915: Refresh cached DP port register value on resume
  drm/i915/ilk: Don't disable SSC source if it's in use
  drm/nouveau/disp/sor/gf119: select correct sor when poking training pattern
  drm/nouveau: fix for disabled fbdev emulation
  drm/nouveau/fbcon: fix out-of-bounds memory accesses
  drm/nouveau/gr/gf100-: update sm error decoding from gk20a nvgpu headers
  drm/nouveau/disp/sor/gf119: both links use the same training register
  virtio_balloon: fix PFN format for virtio-1
  drm/dp/mst: Always clear proposed vcpi table for port.
  drm/amdkfd: destroy dbgmgr in notifier release
  drm/amdkfd: unbind only existing processes
  ubi: Make recover_peb power cut aware
  drm/amdgpu/gfx7: fix broken condition check
  drm/radeon: fix asic initialization for virtualized environments
  btrfs: account for non-CoW'd blocks in btrfs_abort_transaction
  percpu: fix synchronization between synchronous map extension and chunk destruction
  percpu: fix synchronization between chunk->map_extend_work and chunk destruction
  af_unix: fix hard linked sockets on overlay
  vfs: add d_real_inode() helper
  arm64: Rework valid_user_regs
  ipmi: Remove smi_msg from waiting_rcv_msgs list before handle_one_recv_msg()
  drm/mgag200: Black screen fix for G200e rev 4
  iommu/amd: Fix unity mapping initialization race
  iommu/vt-d: Enable QI on all IOMMUs before setting root entry
  iommu/arm-smmu: Wire up map_sg for arm-smmu-v3
  base: make module_create_drivers_dir race-free
  tracing: Handle NULL formats in hold_module_trace_bprintk_format()
  HID: multitouch: enable palm rejection for Windows Precision Touchpad
  HID: hiddev: validate num_values for HIDIOCGUSAGES, HIDIOCSUSAGES commands
  HID: elo: kill not flush the work
  KVM: nVMX: VMX instructions: fix segment checks when L1 is in long mode.
  kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTES
  KEYS: potential uninitialized variable
  ARCv2: LLSC: software backoff is NOT needed starting HS2.1c
  ARCv2: Check for LL-SC livelock only if LLSC is enabled
  ipv6: Fix mem leak in rt6i_pcpu
  cdc_ncm: workaround for EM7455 "silent" data interface
  net_sched: fix mirrored packets checksum
  packet: Use symmetric hash for PACKET_FANOUT_HASH.
  sched/fair: Fix cfs_rq avg tracking underflow
  UBIFS: Implement ->migratepage()
  mm: Export migrate_page_move_mapping and migrate_page_copy
  MIPS: KVM: Fix modular KVM under QEMU
  ARM: 8579/1: mm: Fix definition of pmd_mknotpresent
  ARM: 8578/1: mm: ensure pmd_present only checks the valid bit
  ARM: imx6ul: Fix Micrel PHY mask
  NFS: Fix another OPEN_DOWNGRADE bug
  make nfs_atomic_open() call d_drop() on all ->open_context() errors.
  nfsd: check permissions when setting ACLs
  posix_acl: Add set_posix_acl
  nfsd: Extend the mutex holding region around in nfsd4_process_open2()
  nfsd: Always lock state exclusively.
  nfsd4/rpc: move backchannel create logic into rpc code
  writeback: use higher precision calculation in domain_dirty_limits()
  thermal: cpu_cooling: fix improper order during initialization
  uvc: Forward compat ioctls to their handlers directly
  Revert "gpiolib: Split GPIO flags parsing and GPIO configuration"
  x86/amd_nb: Fix boot crash on non-AMD systems
  kprobes/x86: Clear TF bit in fault on single-stepping
  x86, build: copy ldlinux.c32 to image.iso
  locking/static_key: Fix concurrent static_key_slow_inc()
  locking/qspinlock: Fix spin_unlock_wait() some more
  locking/ww_mutex: Report recursive ww_mutex locking early
  of: irq: fix of_irq_get[_byname]() kernel-doc
  of: fix autoloading due to broken modalias with no 'compatible'
  mnt: If fs_fully_visible fails call put_filesystem.
  mnt: Account for MS_RDONLY in fs_fully_visible
  mnt: fs_fully_visible test the proper mount for MNT_LOCKED
  usb: common: otg-fsm: add license to usb-otg-fsm
  USB: EHCI: declare hostpc register as zero-length array
  usb: dwc2: fix regression on big-endian PowerPC/ARM systems
  powerpc/tm: Always reclaim in start_thread() for exec() class syscalls
  powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
  powerpc/pseries: Fix PCI config address for DDW
  powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism
  IB/mlx4: Properly initialize GRH TClass and FlowLabel in AHs
  IB/cm: Fix a recently introduced locking bug
  EDAC, sb_edac: Fix rank lookup on Broadwell
  mac80211: Fix mesh estab_plinks counting in STA removal case
  mac80211_hwsim: Add missing check for HWSIM_ATTR_SIGNAL
  mac80211: mesh: flush mesh paths unconditionally
  mac80211: fix fast_tx header alignment
  Linux 4.4.15
  usb: dwc3: exynos: Fix deferred probing storm.
  usb: host: ehci-tegra: Grab the correct UTMI pads reset
  usb: gadget: fix spinlock dead lock in gadgetfs
  USB: mos7720: delete parport
  xhci: Fix handling timeouted commands on hosts in weird states.
  USB: xhci: Add broken streams quirk for Frescologic device id 1009
  usb: xhci-plat: properly handle probe deferral for devm_clk_get()
  xhci: Cleanup only when releasing primary hcd
  usb: musb: host: correct cppi dma channel for isoch transfer
  usb: musb: Ensure rx reinit occurs for shared_fifo endpoints
  usb: musb: Stop bulk endpoint while queue is rotated
  usb: musb: only restore devctl when session was set in backup
  usb: quirks: Add no-lpm quirk for Acer C120 LED Projector
  usb: quirks: Fix sorting
  USB: uas: Fix slave queue_depth not being set
  crypto: user - re-add size check for CRYPTO_MSG_GETALG
  crypto: ux500 - memmove the right size
  crypto: vmx - Increase priority of aes-cbc cipher
  AX.25: Close socket connection on session completion
  bpf: try harder on clones when writing into skb
  net: alx: Work around the DMA RX overflow issue
  net: macb: fix default configuration for GMAC on AT91
  neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit()
  bpf, perf: delay release of BPF prog after grace period
  sock_diag: do not broadcast raw socket destruction
  Bridge: Fix ipv6 mc snooping if bridge has no ipv6 address
  ipmr/ip6mr: Initialize the last assert time of mfc entries.
  netem: fix a use after free
  esp: Fix ESN generation under UDP encapsulation
  sit: correct IP protocol used in ipip6_err
  net: Don't forget pr_fmt on net_dbg_ratelimited for CONFIG_DYNAMIC_DEBUG
  net_sched: fix pfifo_head_drop behavior vs backlog
  sdcardfs: Truncate packages_gid.list on overflow
  UPSTREAM: cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind
  BACKPORT: proc: add /proc/<pid>/timerslack_ns interface
  BACKPORT: timer: convert timer_slack_ns from unsigned long to u64
  netfilter: xt_quota2: make quota2_log work well
  Revert "usb: gadget: prevent change of Host MAC address of 'usb0' interface"
  BACKPORT: PM / sleep: Go direct_complete if driver has no callbacks
  ANDROID: base-cfg: enable UID_CPUTIME
  UPSTREAM: USB: usbfs: fix potential infoleak in devio
  UPSTREAM: ALSA: timer: Fix leak in events via snd_timer_user_ccallback
  UPSTREAM: ALSA: timer: Fix leak in events via snd_timer_user_tinterrupt
  UPSTREAM: ALSA: timer: Fix leak in SNDRV_TIMER_IOCTL_PARAMS
  ANDROID: configs: remove unused configs
  ANDROID: cpu: send KOBJ_ONLINE event when enabling cpus
  ANDROID: dm verity fec: initialize recursion level
  ANDROID: dm verity fec: fix RS block calculation
  Linux 4.4.14
  netfilter: x_tables: introduce and use xt_copy_counters_from_user
  netfilter: x_tables: do compat validation via translate_table
  netfilter: x_tables: xt_compat_match_from_user doesn't need a retval
  netfilter: ip6_tables: simplify translate_compat_table args
  netfilter: ip_tables: simplify translate_compat_table args
  netfilter: arp_tables: simplify translate_compat_table args
  netfilter: x_tables: don't reject valid target size on some architectures
  netfilter: x_tables: validate all offsets and sizes in a rule
  netfilter: x_tables: check for bogus target offset
  netfilter: x_tables: check standard target size too
  netfilter: x_tables: add compat version of xt_check_entry_offsets
  netfilter: x_tables: assert minimum target size
  netfilter: x_tables: kill check_entry helper
  netfilter: x_tables: add and use xt_check_entry_offsets
  netfilter: x_tables: validate targets of jumps
  netfilter: x_tables: don't move to non-existent next rule
  drm/core: Do not preserve framebuffer on rmfb, v4.
  crypto: qat - fix adf_ctl_drv.c:undefined reference to adf_init_pf_wq
  netfilter: x_tables: fix unconditional helper
  netfilter: x_tables: make sure e->next_offset covers remaining blob size
  netfilter: x_tables: validate e->target_offset early
  MIPS: Fix 64k page support for 32 bit kernels.
  sparc64: Fix return from trap window fill crashes.
  sparc: Harden signal return frame checks.
  sparc64: Take ctx_alloc_lock properly in hugetlb_setup().
  sparc64: Reduce TLB flushes during hugepte changes
  sparc/PCI: Fix for panic while enabling SR-IOV
  sparc64: Fix sparc64_set_context stack handling.
  sparc64: Fix numa node distance initialization
  sparc64: Fix bootup regressions on some Kconfig combinations.
  sparc: Fix system call tracing register handling.
  fix d_walk()/non-delayed __d_free() race
  sched: panic on corrupted stack end
  proc: prevent stacking filesystems on top
  x86/entry/traps: Don't force in_interrupt() to return true in IST handlers
  wext: Fix 32 bit iwpriv compatibility issue with 64 bit Kernel
  ecryptfs: forbid opening files without mmap handler
  memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem()
  parisc: Fix pagefault crash in unaligned __get_user() call
  pinctrl: mediatek: fix dual-edge code defect
  powerpc/pseries: Add POWER8NVL support to ibm,client-architecture-support call
  powerpc: Use privileged SPR number for MMCR2
  powerpc: Fix definition of SIAR and SDAR registers
  powerpc/pseries/eeh: Handle RTAS delay requests in configure_bridge
  arm64: mm: always take dirty state from new pte in ptep_set_access_flags
  arm64: Provide "model name" in /proc/cpuinfo for PER_LINUX32 tasks
  crypto: ccp - Fix AES XTS error for request sizes above 4096
  crypto: public_key: select CRYPTO_AKCIPHER
  irqchip/gic-v3: Fix ICC_SGI1R_EL1.INTID decoding mask
  s390/bpf: reduce maximum program size to 64 KB
  s390/bpf: fix recache skb->data/hlen for skb_vlan_push/pop
  gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings
  ARM: fix PTRACE_SETVFPREGS on SMP systems
  ALSA: hda/realtek: Add T560 docking unit fixup
  ALSA: hda/realtek - Add support for new codecs ALC700/ALC701/ALC703
  ALSA: hda/realtek - ALC256 speaker noise issue
  ALSA: hda - Fix headset mic detection problem for Dell machine
  ALSA: hda - Add PCI ID for Kabylake
  KVM: irqfd: fix NULL pointer dereference in kvm_irq_map_gsi
  KVM: x86: fix OOPS after invalid KVM_SET_DEBUGREGS
  vxlan, gre, geneve: Set a large MTU on ovs-created tunnel devices
  geneve: Relax MTU constraints
  vxlan: Relax MTU constraints
  ipv6: Skip XFRM lookup if dst_entry in socket cache is valid
  l2tp: fix configuration passed to setup_udp_tunnel_sock()
  bridge: Don't insert unnecessary local fdb entry on changing mac address
  tcp: record TLP and ER timer stats in v6 stats
  vxlan: Accept user specified MTU value when create new vxlan link
  team: don't call netdev_change_features under team->lock
  sfc: on MC reset, clear PIO buffer linkage in TXQs
  bpf, inode: disallow userns mounts
  uapi glibc compat: fix compilation when !__USE_MISC in glibc
  udp: prevent skbs lingering in tunnel socket queues
  bpf: Use mount_nodev not mount_ns to mount the bpf filesystem
  tuntap: correctly wake up process during uninit
  switchdev: pass pointer to fib_info instead of copy
  tipc: fix nametable publication field in nl compat
  netlink: Fix dump skb leak/double free
  tipc: check nl sock before parsing nested attributes
  scsi: Add QEMU CD-ROM to VPD Inquiry Blacklist
  scsi_lib: correctly retry failed zero length REQ_TYPE_FS commands
  cs-etm: associating output packet with CPU they executed on
  cs-etm: removing unecessary structure field
  cs-etm: account for each trace buffer in the queue
  cs-etm: avoid casting variable
  perf tools: fixing Makefile problems
  perf tools: new naming convention for openCSD
  perf scripts: Add python scripts for CoreSight traces
  perf tools: decoding capailitity for CoreSight traces
  perf symbols: Check before overwriting build_id
  perf tools: pushing driver configuration down to the kernel
  perf tools: add infrastructure for PMU specific configuration
  coresight: etm-perf: incorporating sink definition from the cmd line
  coresight: adding sink parameter to function coresight_build_path()
  perf: passing struct perf_event to function setup_aux()
  perf/core: adding PMU driver specific configuration
  perf tools: adding coresight etm PMU record capabilities
  perf tools: making coresight PMU listable
  coresight: tmc: implementing TMC-ETR AUX space API
  coresight: Add support for Juno platform
  coresight: Handle build path error
  coresight: Fix erroneous memset in tmc_read_unprepare_etr
  coresight: Fix tmc_read_unprepare_etr
  coresight: Fix NULL pointer dereference in _coresight_build_path
  ANDROID: dm verity fec: add missing release from fec_ktype
  ANDROID: dm verity fec: limit error correction recursion
  ANDROID: restrict access to perf events
  FROMLIST: security,perf: Allow further restriction of perf_event_open
  BACKPORT: perf tools: Document the perf sysctls
  Revert "armv6 dcc tty driver"
  Revert "arm: dcc_tty: fix armv6 dcc tty build failure"
  ARM64: Ignore Image-dtb from git point of view
  arm64: add option to build Image-dtb
  ANDROID: usb: gadget: f_midi: set fi->f to NULL when free f_midi function
  Linux 4.4.13
  xfs: handle dquot buffer readahead in log recovery correctly
  xfs: print name of verifier if it fails
  xfs: skip stale inodes in xfs_iflush_cluster
  xfs: fix inode validity check in xfs_iflush_cluster
  xfs: xfs_iflush_cluster fails to abort on error
  xfs: Don't wrap growfs AGFL indexes
  xfs: disallow rw remount on fs with unknown ro-compat features
  gcov: disable tree-loop-im to reduce stack usage
  scripts/package/Makefile: rpmbuild add support of RPMOPTS
  dma-debug: avoid spinlock recursion when disabling dma-debug
  PM / sleep: Handle failures in device_suspend_late() consistently
  ext4: silence UBSAN in ext4_mb_init()
  ext4: address UBSAN warning in mb_find_order_for_block()
  ext4: fix oops on corrupted filesystem
  ext4: clean up error handling when orphan list is corrupted
  ext4: fix hang when processing corrupted orphaned inode list
  drm/imx: Match imx-ipuv3-crtc components using device node in platform data
  drm/i915: Don't leave old junk in ilk active watermarks on readout
  drm/atomic: Verify connector->funcs != NULL when clearing states
  drm/fb_helper: Fix references to dev->mode_config.num_connector
  drm/i915/fbdev: Fix num_connector references in intel_fb_initial_config()
  drm/amdgpu: Fix hdmi deep color support.
  drm/amdgpu: use drm_mode_vrefresh() rather than mode->vrefresh
  drm/vmwgfx: Fix order of operation
  drm/vmwgfx: use vmw_cmd_dx_cid_check for query commands.
  drm/vmwgfx: Enable SVGA_3D_CMD_DX_SET_PREDICATION
  drm/gma500: Fix possible out of bounds read
  sunrpc: fix stripping of padded MIC tokens
  xen: use same main loop for counting and remapping pages
  xen/events: Don't move disabled irqs
  powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()
  Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
  powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()
  powerpc/book3s64: Fix branching to OOL handlers in relocatable kernel
  pipe: limit the per-user amount of pages allocated in pipes
  QE-UART: add "fsl,t1040-ucc-uart" to of_device_id
  wait/ptrace: assume __WALL if the child is traced
  mm: use phys_addr_t for reserve_bootmem_region() arguments
  media: v4l2-compat-ioctl32: fix missing reserved field copy in put_v4l2_create32
  PCI: Disable all BAR sizing for devices with non-compliant BARs
  pinctrl: exynos5440: Use off-stack memory for pinctrl_gpio_range
  clk: bcm2835: divider value has to be 1 or more
  clk: bcm2835: pll_off should only update CM_PLL_ANARST
  clk: at91: fix check of clk_register() returned value
  clk: bcm2835: Fix PLL poweron
  cpuidle: Fix cpuidle_state_is_coupled() argument in cpuidle_enter()
  cpuidle: Indicate when a device has been unregistered
  PM / Runtime: Fix error path in pm_runtime_force_resume()
  mfd: intel_soc_pmic_core: Terminate panel control GPIO lookup table correctly
  mfd: intel-lpss: Save register context on suspend
  hwmon: (ads7828) Enable internal reference
  aacraid: Fix for KDUMP driver hang
  aacraid: Fix for aac_command_thread hang
  aacraid: Relinquish CPU during timeout wait
  rtlwifi: pci: use dev_kfree_skb_irq instead of kfree_skb in rtl_pci_reset_trx_ring
  rtlwifi: Fix logic error in enter/exit power-save mode
  rtlwifi: btcoexist: Implement antenna selection
  rtlwifi: rtl8723be: Add antenna select module parameter
  hwrng: exynos - Fix unbalanced PM runtime put on timeout error path
  ath5k: Change led pin configuration for compaq c700 laptop
  ath10k: fix kernel panic, move arvifs list head init before htt init
  ath10k: fix rx_channel during hw reconfigure
  ath10k: fix firmware assert in monitor mode
  ath10k: fix debugfs pktlog_filter write
  ath9k: Fix LED polarity for some Mini PCI AR9220 MB92 cards.
  ath9k: Add a module parameter to invert LED polarity.
  ARM: dts: imx35: restore existing used clock enumeration
  ARM: dts: exynos: Add interrupt line to MAX8997 PMIC on exynos4210-trats
  ARM: dts: at91: fix typo in sama5d2 PIN_PD24 description
  ARM: mvebu: fix GPIO config on the Linksys boards
  Input: uinput - handle compat ioctl for UI_SET_PHYS
  ASoC: ak4642: Enable cache usage to fix crashes on resume
  affs: fix remount failure when there are no options changed
  MIPS: VDSO: Build with `-fno-strict-aliasing'
  MIPS: lib: Mark intrinsics notrace
  MIPS: Build microMIPS VDSO for microMIPS kernels
  MIPS: Fix sigreturn via VDSO on microMIPS kernel
  MIPS: ptrace: Prevent writes to read-only FCSR bits
  MIPS: ptrace: Fix FP context restoration FCSR regression
  MIPS: Disable preemption during prctl(PR_SET_FP_MODE, ...)
  MIPS: Prevent "restoration" of MSA context in non-MSA kernels
  MIPS: Fix MSA ld_*/st_* asm macros to use PTR_ADDU
  MIPS: Use copy_s.fmt rather than copy_u.fmt
  MIPS: Loongson-3: Reserve 32MB for RS780E integrated GPU
  MIPS: Reserve nosave data for hibernation
  MIPS: ath79: make bootconsole wait for both THRE and TEMT
  MIPS: Sync icache & dcache in set_pte_at
  MIPS: Handle highmem pages in __update_cache
  MIPS: Flush highmem pages in __flush_dcache_page
  MIPS: Fix watchpoint restoration
  MIPS: Fix uapi include in exported asm/siginfo.h
  MIPS: Fix siginfo.h to use strict posix types
  MIPS: Avoid using unwind_stack() with usermode
  MIPS: Don't unwind to user mode with EVA
  MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC
  MIPS: math-emu: Fix jalr emulation when rd == $0
  MIPS64: R6: R2 emulation bugfix
  coresight: etb10: adjust read pointer only when needed
  coresight: configuring ETF in FIFO mode when acting as link
  coresight: tmc: implementing TMC-ETF AUX space API
  coresight: moving struct cs_buffers to header file
  coresight: tmc: keep track of memory width
  coresight: tmc: make sysFS and Perf mode mutually exclusive
  coresight: tmc: dump system memory content only when needed
  coresight: tmc: adding mode of operation for link/sinks
  coresight: tmc: getting rid of multiple read access
  coresight: tmc: allocating memory when needed
  coresight: tmc: making prepare/unprepare functions generic
  coresight: tmc: splitting driver in ETB/ETF and ETR components
  coresight: tmc: cleaning up header file
  coresight: tmc: introducing new header file
  coresight: tmc: clearly define number of transfers per burst
  coresight: tmc: re-implementing tmc_read_prepare/unprepare() functions
  coresight: tmc: waiting for TMCReady bit before programming
  coresight: tmc: modifying naming convention
  coresight: tmc: adding sysFS management entries
  coresight: etm4x: add tracer ID for A72 Maia processor.
  coresight: etb10: fixing the right amount of words to read
  coresight: stm: adding driver for CoreSight STM component
  coresight: adding path for STM device
  coresight: etm4x: modify q_support type
  coresight: no need to do the forced type conversion
  coresight: removing gratuitous boot time log messages
  coresight: etb10: splitting sysFS "status" entry
  coresight: moving coresight_simple_func() to header file
  coresight: etm4x: implementing the perf PMU API
  coresight: etm4x: implementing user/kernel mode tracing
  coresight: etm4x: moving etm_drvdata::enable to atomic field
  coresight: etm4x: unlocking tracers in default arch init
  coresight: etm4x: splitting etmv4 default configuration
  coresight: etm4x: splitting struct etmv4_drvdata
  coresight: etm4x: adding config and traceid registers
  coresight: etm4x: moving sysFS entries to a dedicated file
  stm class: Support devices that override software assigned masters
  stm class: Remove unnecessary pointer increment
  stm class: Fix stm device initialization order
  stm class: Do not leak the chrdev in error path
  stm class: Remove a pointless line
  stm class: stm_heartbeat: Make nr_devs parameter read-only
  stm class: dummy_stm: Make nr_dummies parameter read-only
  MAINTAINERS: Add a git tree for the stm class
  perf/ring_buffer: Document AUX API usage
  perf/core: Free AUX pages in unmap path
  perf/ring_buffer: Refuse to begin AUX transaction after rb->aux_mmap_count drops
  perf auxtrace: Add perf_evlist pointer to *info_priv_size()
  perf session: Simplify tool stubs
  perf inject: Hit all DSOs for AUX data in JIT and other cases
  perf tools: tracepoint_error() can receive e=NULL, robustify it
  perf evlist: Make perf_evlist__open() open evsels with their cpus and threads (like perf record does)
  perf evsel: Introduce disable() method
  perf cpumap: Auto initialize cpu__max_{node,cpu}
  drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
  drivers/hwtracing: make coresight-* explicitly non-modular
  coresight: introducing a global trace ID function
  coresight: etm-perf: new PMU driver for ETM tracers
  coresight: etb10: implementing AUX API
  coresight: etb10: adding operation mode for sink->enable()
  coresight: etb10: moving to local atomic operations
  coresight: etm3x: implementing perf_enable/disable() API
  coresight: etm3x: implementing user/kernel mode tracing
  coresight: etm3x: consolidating initial config
  coresight: etm3x: changing default trace configuration
  coresight: etm3x: set progbit to stop trace collection
  coresight: etm3x: adding operation mode for etm_enable()
  coresight: etm3x: splitting struct etm_drvdata
  coresight: etm3x: unlocking tracers in default arch init
  coresight: etm3x: moving sysFS entries to dedicated file
  coresight: etm3x: moving etm_readl/writel to header file
  coresight: moving PM runtime operations to core framework
  coresight: add API to get sink from path
  coresight: associating path with session rather than tracer
  coresight: etm4x: Check every parameter used by dma_xx_coherent.
  coresight: "DEVICE_ATTR_RO" should defined as static.
  coresight: implementing 'cpu_id()' API
  coresight: removing bind/unbind options from sysfs
  coresight: remove csdev's link from topology
  coresight: release reference taken by 'bus_find_device()'
  coresight: coresight_unregister() function cleanup
  coresight: fixing lockdep error
  coresight: fixing indentation problem
  coresight: Fix a typo in Kconfig
  coresight: checking for NULL string in coresight_name_match()
  perf/core: Disable the event on a truncated AUX record
  perf/core: Don't leak event in the syscall error path
  perf/core: Fix perf_sched_count derailment
  stm class: dummy_stm: Add link callback for fault injection
  stm class: Plug stm device's unlink callback
  stm class: Fix a race in unlinking
  stm class: Fix unbalanced module/device refcounting
  stm class: Guard output assignment against concurrency
  stm class: Fix unlocking braino in the error path
  stm class: Add heartbeat stm source device
  stm class: dummy_stm: Create multiple devices
  stm class: Support devices with multiple instances
  stm class: Use driver's packet callback return value
  stm class: Prevent user-controllable allocations
  stm class: Fix link list locking
  stm class: Fix locking in unbinding policy path
  stm class: Select CONFIG_SRCU
  stm class: Hide STM-specific options if STM is disabled
  perf: Synchronously free aux pages in case of allocation failure
  Linux 4.4.12
  kbuild: move -Wunused-const-variable to W=1 warning level
  Revert "scsi: fix soft lockup in scsi_remove_target() on module removal"
  scsi: Add intermediate STARGET_REMOVE state to scsi_target_state
  hpfs: implement the show_options method
  hpfs: fix remount failure when there are no options changed
  UBI: Fix static volume checks when Fastmap is used
  SIGNAL: Move generic copy_siginfo() to signal.h
  thunderbolt: Fix double free of drom buffer
  IB/srp: Fix a debug kernel crash
  ALSA: hda - Fix headset mic detection problem for one Dell machine
  ALSA: hda/realtek - Add support for ALC295/ALC3254
  ALSA: hda - Fix headphone noise on Dell XPS 13 9360
  ALSA: hda/realtek - New codecs support for ALC234/ALC274/ALC294
  mcb: Fixed bar number assignment for the gdd
  clk: bcm2835: add locking to pll*_on/off methods
  locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()
  serial: samsung: Reorder the sequence of clock control when call s3c24xx_serial_set_termios()
  serial: 8250_mid: recognize interrupt source in handler
  serial: 8250_mid: use proper bar for DNV platform
  serial: 8250_pci: fix divide error bug if baud rate is 0
  Fix OpenSSH pty regression on close
  tty/serial: atmel: fix hardware handshake selection
  TTY: n_gsm, fix false positive WARN_ON
  tty: vt, return error when con_startup fails
  xen/x86: actually allocate legacy interrupts on PV guests
  KVM: x86: mask CPUID(0xD,0x1).EAX against host value
  MIPS: KVM: Fix timer IRQ race when writing CP0_Compare
  MIPS: KVM: Fix timer IRQ race when freezing timer
  KVM: x86: fix ordering of cr0 initialization code in vmx_cpu_reset
  KVM: MTRR: remove MSR 0x2f8
  staging: comedi: das1800: fix possible NULL dereference
  usb: gadget: udc: core: Fix argument of dev_err() in usb_gadget_map_request()
  USB: leave LPM alone if possible when binding/unbinding interface drivers
  usb: misc: usbtest: fix pattern tests for scatterlists.
  usb: f_mass_storage: test whether thread is running before starting another
  usb: gadget: f_fs: Fix EFAULT generation for async read operations
  USB: serial: option: add even more ZTE device ids
  USB: serial: option: add more ZTE device ids
  USB: serial: option: add support for Cinterion PH8 and AHxx
  USB: serial: io_edgeport: fix memory leaks in probe error path
  USB: serial: io_edgeport: fix memory leaks in attach error path
  USB: serial: quatech2: fix use-after-free in probe error path
  USB: serial: keyspan: fix use-after-free in probe error path
  USB: serial: mxuport: fix use-after-free in probe error path
  mei: bus: call mei_cl_read_start under device lock
  mei: amthif: discard not read messages
  mei: fix NULL dereferencing during FW initiated disconnection
  Bluetooth: vhci: Fix race at creating hci device
  Bluetooth: vhci: purge unhandled skbs
  Bluetooth: vhci: fix open_timeout vs. hdev race
  mmc: sdhci-pci: Remove MMC_CAP_BUS_WIDTH_TEST for Intel controllers
  mmc: longer timeout for long read time quirk
  dell-rbtn: Ignore ACPI notifications if device is suspended
  ACPI / osi: Fix an issue that acpi_osi=!* cannot disable ACPICA internal strings
  mmc: sdhci-acpi: Remove MMC_CAP_BUS_WIDTH_TEST for Intel controllers
  mmc: mmc: Fix partition switch timeout for some eMMCs
  can: fix handling of unmodifiable configuration options
  irqchip/gic-v3: Configure all interrupts as non-secure Group-1
  irqchip/gic: Ensure ordering between read of INTACK and shared data
  Input: pwm-beeper - fix - scheduling while atomic
  mfd: omap-usb-tll: Fix scheduling while atomic BUG
  sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systems
  clk: qcom: msm8916: Fix crypto clock flags
  crypto: sun4i-ss - Replace spinlock_bh by spin_lock_irq{save|restore}
  crypto: talitos - fix ahash algorithms registration
  crypto: caam - fix caam_jr_alloc() ret code
  ring-buffer: Prevent overflow of size in ring_buffer_resize()
  ring-buffer: Use long for nr_pages to avoid overflow failures
  asix: Fix offset calculation in asix_rx_fixup() causing slow transmissions
  fs/cifs: correctly to anonymous authentication for the NTLM(v2) authentication
  fs/cifs: correctly to anonymous authentication for the NTLM(v1) authentication
  fs/cifs: correctly to anonymous authentication for the LANMAN authentication
  fs/cifs: correctly to anonymous authentication via NTLMSSP
  remove directory incorrectly tries to set delete on close on non-empty directories
  kvm: arm64: Fix EC field in inject_abt64
  arm/arm64: KVM: Enforce Break-Before-Make on Stage-2 page tables
  arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Implement ptep_set_access_flags() for hardware AF/DBM
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  ext4: iterate over buffer heads correctly in move_extent_per_page()
  perf test: Fix build of BPF and LLVM on older glibc libraries
  perf/core: Fix perf_event_open() vs. execve() race
  perf/x86/intel/pt: Generate PMI in the STOP region as well
  Btrfs: don't use src fd for printk
  UPSTREAM: mac80211: fix "warning: ‘target_metric’ may be used uninitialized"
  Revert "drivers: power: use 'current' instead of 'get_current()'"
  cpufreq: interactive: drop cpufreq_{get,put}_global_kobject func calls
  Revert "cpufreq: interactive: build fixes for 4.4"
  xt_qtaguid: Fix panic caused by processing non-full socket.
  fiq_debugger: Add fiq_debugger.disable option
  UPSTREAM: procfs: fixes pthread cross-thread naming if !PR_DUMPABLE
  FROMLIST: wlcore: Disable filtering in AP role
  Revert "drivers: power: Add watchdog timer to catch drivers which lockup during suspend."
  fiq_debugger: Add option to apply uart overlay by FIQ_DEBUGGER_UART_OVERLAY
  Revert "Recreate asm/mach/mmc.h include file"
  Revert "ARM: Add 'card_present' state to mmc_platfrom_data"
  usb: dual-role: make stub functions inline
  Revert "mmc: Add status IRQ and status callback function to mmc platform data"
  quick selinux support for tracefs
  Revert "hid-multitouch: Filter collections by application usage."
  Revert "HID: steelseries: validate output report details"
  xt_qtaguid: Fix panic caused by synack processing
  Revert "mm: vmscan: Add a debug file for shrinkers"
  Revert "SELinux: Enable setting security contexts on rootfs inodes."
  Revert "SELinux: build fix for 4.1"
  fuse: Add support for d_canonical_path
  vfs: change d_canonical_path to take two paths
  android: recommended.cfg: remove CONFIG_UID_STAT
  netfilter: xt_qtaguid: seq_printf fixes
  Revert "misc: uidstat: Adding uid stat driver to collect network statistics."
  Revert "net: activity_stats: Add statistics for network transmission activity"
  Revert "net: activity_stats: Stop using obsolete create_proc_read_entry api"
  Revert "misc: uidstat: avoid create_stat() race and blockage."
  Revert "misc: uidstat: Remove use of obsolete create_proc_read_entry api"
  Revert "misc seq_printf fixes for 4.4"
  Revert "misc: uid_stat: Include linux/atomic.h instead of asm/atomic.h"
  Revert "net: socket ioctl to reset connections matching local address"
  Revert "net: fix iterating over hashtable in tcp_nuke_addr()"
  Revert "net: fix crash in tcp_nuke_addr()"
  Revert "Don't kill IPv4 sockets when killing IPv6 sockets was requested."
  Revert "tcp: Fix IPV6 module build errors"
  android: base-cfg: remove CONFIG_SWITCH
  Revert "switch: switch class and GPIO drivers."
  Revert "drivers: switch: remove S_IWUSR from dev_attr"
  ANDROID: base-cfg: enable CONFIG_IP_NF_NAT
  BACKPORT: selinux: restrict kernel module loading
  android: base-cfg: enable CONFIG_QUOTA

Conflicts:
	Documentation/sysctl/kernel.txt
	drivers/cpufreq/cpufreq_interactive.c
	drivers/hwtracing/coresight/Kconfig
	drivers/hwtracing/coresight/Makefile
	drivers/hwtracing/coresight/coresight-etm4x.c
	drivers/hwtracing/coresight/coresight-etm4x.h
	drivers/hwtracing/coresight/coresight-priv.h
	drivers/hwtracing/coresight/coresight-stm.c
	drivers/hwtracing/coresight/coresight-tmc.c
	drivers/mmc/core/core.c
	include/linux/coresight-stm.h
	include/linux/coresight.h
	include/linux/msm_mdp.h
	include/uapi/linux/coresight-stm.h
	kernel/events/core.c
	kernel/sched/fair.c
	net/Makefile
	net/ipv4/netfilter/arp_tables.c
	net/ipv4/netfilter/ip_tables.c
	net/ipv4/tcp.c
	net/ipv6/netfilter/ip6_tables.c
	net/netfilter/xt_quota2.c
	sound/core/pcm.c

Change-Id: I17aa0002815014e9bddc47e67769a53c15768a99
Signed-off-by: Runmin Wang <runminw@codeaurora.org>
2016-10-28 10:48:35 -07:00
Olav Haugan
fc70615291 cpumask: Add cpu isolation support
Add bitmask and corresponding supporting functions for cpu isolation.

Change-Id: Ice1a9503666a2b720bdb324289ca55ceb33097cd
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
2016-09-20 17:47:13 -07:00
Kaushal Kumar
36131fdc87 sched: Remove synchronize rcu/sched calls from _cpu_down
There is no need for sync_sched() in _cpu_down as stop_machine()
provides that barrier implicitly. Removing it also helps improve
hot-unplug latency.

The sync_sched/rcu were earlier removed for the same reason by the
commit 9ee349ad6d ("sched: Fix set_cpu_active() in cpu_down()"),
but recently got added as part of commit <6acce3ef84520537> ("sched:
Remove get_online_cpus() usage.").

CRs-Fixed: 1048941
Change-Id: I97763004454d082d3cc2d9d9dbef7da923608600
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Signed-off-by: Runmin Wang <runminw@codeaurora.org>
2016-08-02 10:19:16 -07:00
Thierry Strudel
0c718f7d5b ANDROID: cpu: send KOBJ_ONLINE event when enabling cpus
In case some sysfs nodes needs to be labeled with a different label than
sysfs then user needs to be notified when a core is brought back online.

Signed-off-by: Thierry Strudel <tstrudel@google.com>
Bug: 29359497
Change-Id: I0395c86e01cd49c348fda8f93087d26f88557c91
2016-07-11 12:42:46 +05:30
Arun Bharadwaj
a2b15c0b53 tracing/sched: Add trace events to track cpu hotplug.
Add ftrace event trace_sched_cpu_hotplug to track cpu
hot-add and hot-remove events.

This is useful in a variety of power, performance and
debug analysis scenarios.

Change-Id: I5d202c7a229ffacc3aafb7cf9afee0b0ee7b0931
Signed-off-by: Arun Bharadwaj <abharadw@codeaurora.org>
2016-02-16 13:53:29 -08:00
Todd Poynor
90fbee8f97 Move x86_64 idle notifiers to generic
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>
2016-02-16 13:52:32 -08:00
Linus Torvalds
53528695ff Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "The main changes in this cycle were:

   - sched/fair load tracking fixes and cleanups (Byungchul Park)

   - Make load tracking frequency scale invariant (Dietmar Eggemann)

   - sched/deadline updates (Juri Lelli)

   - stop machine fixes, cleanups and enhancements for bugs triggered by
     CPU hotplug stress testing (Oleg Nesterov)

   - scheduler preemption code rework: remove PREEMPT_ACTIVE and related
     cleanups (Peter Zijlstra)

   - Rework the sched_info::run_delay code to fix races (Peter Zijlstra)

   - Optimize per entity utilization tracking (Peter Zijlstra)

   - ... misc other fixes, cleanups and smaller updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
  sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
  sched: Start stopper early
  stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
  stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
  stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
  stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
  stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
  sched/x86: Fix typo in __switch_to() comments
  sched/core: Remove a parameter in the migrate_task_rq() function
  sched/core: Drop unlikely behind BUG_ON()
  sched/core: Fix task and run queue sched_info::run_delay inconsistencies
  sched/numa: Fix task_tick_fair() from disabling numa_balancing
  sched/core: Add preempt_count invariant check
  sched/core: More notrace annotations
  sched/core: Kill PREEMPT_ACTIVE
  sched/core, sched/x86: Kill thread_info::saved_preempt_count
  sched/core: Simplify preempt_count tests
  sched/core: Robustify preemption leak checks
  sched/core: Stop setting PREEMPT_ACTIVE
  ...
2015-11-03 18:03:50 -08:00
Peter Zijlstra
07f06cb3b5 sched: Start stopper early
Ensure the stopper thread is active 'early', because the load balancer
pretty much assumes that its available. And when 'online && active' the
load-balancer is fully available.

Not only the numa balancing stop_two_cpus() caller relies on it, but
also the self migration stuff does, and at CPU_ONLINE time the cpu
really is 'free' to run anything.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20151009160054.GA10176@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:25:55 +02:00
Oleg Nesterov
c00166d87e stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
1. Change smpboot_unpark_thread() to check ->selfparking, just
   like smpboot_park_thread() does.

2. Introduce stop_machine_unpark() which sets ->enabled and calls
   kthread_unpark().

3. Change smpboot_thread_call() and cpu_stop_init() to call
   stop_machine_unpark() by hand.

This way:

    - IMO the ->selfparking logic becomes more consistent.

    - We can kill the smp_hotplug_thread->pre_unpark() method.

    - We can easily unpark the stopper thread earlier. Say, we
      can move stop_machine_unpark() from smpboot_thread_call()
      to sched_cpu_active() as Peter suggests.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20151009160049.GA10166@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:23:55 +02:00
Oleg Nesterov
233e7f267e stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
cpu_stop_queue_work() checks stopper->enabled before it queues the
work, but ->enabled == T can only guarantee cpu_stop_signal_done()
if we race with cpu_down().

This is not enough for stop_two_cpus() or stop_machine(), they will
deadlock if multi_cpu_stop() won't be called by one of the target
CPU's. stop_machine/stop_cpus are fine, they rely on stop_cpus_mutex.
But stop_two_cpus() has to check cpu_active() to avoid the same race
with hotplug, and this check is very unobvious and probably not even
correct if we race with cpu_up().

Change cpu_down() pass to clear ->enabled before cpu_stopper_thread()
flushes the pending ->works and returns with KTHREAD_SHOULD_PARK set.

Note also that smpboot_thread_call() calls cpu_stop_unpark() which
sets enabled == T at CPU_ONLINE stage, so this CPU can't go away until
cpu_stopper_thread() is called at least once. This all means that if
cpu_stop_queue_work() succeeds, we know that work->fn() will be called.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20151008145131.GA18139@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 10:23:53 +02:00
Paul E. McKenney
02ef3c4a2a cpu: Remove try_get_online_cpus()
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>
2015-10-07 16:02:49 -07:00
Oleg Nesterov
a75a6068da cpu/hotplug: Read_lock(tasklist_lock) doesn't need to disable irqs
check_for_tasks() doesn't need to disable irqs, recursive
read_lock() from interrupt is fine.

While at it, s/do_each_thread/for_each_process_thread/.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kirill Tkhai <ktkhai@odin.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Kirill Tkhai <ktkhai@parallels.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150910130750.GA20055@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-12 11:54:27 +02:00
Linus Torvalds
a1d8561172 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The biggest change in this cycle is the rewrite of the main SMP load
  balancing metric: the CPU load/utilization.  The main goal was to make
  the metric more precise and more representative - see the changelog of
  this commit for the gory details:

    9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")

  It is done in a way that significantly reduces complexity of the code:

    5 files changed, 249 insertions(+), 494 deletions(-)

  and the performance testing results are encouraging.  Nevertheless we
  need to keep an eye on potential regressions, since this potentially
  affects every SMP workload in existence.

  This work comes from Yuyang Du.

  Other changes:

   - SCHED_DL updates.  (Andrea Parri)

   - Simplify architecture callbacks by removing finish_arch_switch().
     (Peter Zijlstra et al)

   - cputime accounting: guarantee stime + utime == rtime.  (Peter
     Zijlstra)

   - optimize idle CPU wakeups some more - inspired by Facebook server
     loads.  (Mike Galbraith)

   - stop_machine fixes and updates.  (Oleg Nesterov)

   - Introduce the 'trace_sched_waking' tracepoint.  (Peter Zijlstra)

   - sched/numa tweaks.  (Srikar Dronamraju)

   - misc fixes and small cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  sched/deadline: Fix comment in enqueue_task_dl()
  sched/deadline: Fix comment in push_dl_tasks()
  sched: Change the sched_class::set_cpus_allowed() calling context
  sched: Make sched_class::set_cpus_allowed() unconditional
  sched: Fix a race between __kthread_bind() and sched_setaffinity()
  sched: Ensure a task has a non-normalized vruntime when returning back to CFS
  sched/numa: Fix NUMA_DIRECT topology identification
  tile: Reorganize _switch_to()
  sched, sparc32: Update scheduler comments in copy_thread()
  sched: Remove finish_arch_switch()
  sched, tile: Remove finish_arch_switch
  sched, sh: Fold finish_arch_switch() into switch_to()
  sched, score: Remove finish_arch_switch()
  sched, avr32: Remove finish_arch_switch()
  sched, MIPS: Get rid of finish_arch_switch()
  sched, arm: Remove finish_arch_switch()
  sched/fair: Clean up load average references
  sched/fair: Provide runnable_load_avg back to cfs_rq
  sched/fair: Remove task and group entity load when they are dead
  sched/fair: Init cfs_rq's sched_entity load average
  ...
2015-08-31 20:26:22 -07:00
Linus Torvalds
7073bc6612 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main RCU changes in this cycle are:

   - the combination of tree geometry-initialization simplifications and
     OS-jitter-reduction changes to expedited grace periods.  These two
     are stacked due to the large number of conflicts that would
     otherwise result.

   - privatize smp_mb__after_unlock_lock().

     This commit moves the definition of smp_mb__after_unlock_lock() to
     kernel/rcu/tree.h, in recognition of the fact that RCU is the only
     thing using this, that nothing else is likely to use it, and that
     it is likely to go away completely.

   - documentation updates.

   - torture-test updates.

   - misc fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  rcu,locking: Privatize smp_mb__after_unlock_lock()
  rcu: Silence lockdep false positive for expedited grace periods
  rcu: Don't disable CPU hotplug during OOM notifiers
  scripts: Make checkpatch.pl warn on expedited RCU grace periods
  rcu: Update MAINTAINERS entry
  rcu: Clarify CONFIG_RCU_EQS_DEBUG help text
  rcu: Fix backwards RCU_LOCKDEP_WARN() in synchronize_rcu_tasks()
  rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()
  rcu: Make rcu_is_watching() really notrace
  cpu: Wait for RCU grace periods concurrently
  rcu: Create a synchronize_rcu_mult()
  rcu: Fix obsolete priority-boosting comment
  rcu: Use WRITE_ONCE in RCU_INIT_POINTER
  rcu: Hide RCU_NOCB_CPU behind RCU_EXPERT
  rcu: Add RCU-sched flavors of get-state and cond-sync
  rcu: Add fastpath bypassing funnel locking
  rcu: Rename RCU_GP_DONE_FQS to RCU_GP_DOING_FQS
  rcu: Pull out wait_event*() condition into helper function
  documentation: Describe new expedited stall warnings
  rcu: Add stall warnings to synchronize_sched_expedited()
  ...
2015-08-31 18:12:07 -07:00
Linus Torvalds
1af115d675 Driver core patches for 4.3-rc1
Here is the new patches for the driver core / sysfs for 4.3-rc1.
 
 Very small number of changes here, all the details are in the shortlog,
 nothing major happening at all this kernel release, which is nice to
 see.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the new patches for the driver core / sysfs for 4.3-rc1.

  Very small number of changes here, all the details are in the
  shortlog, nothing major happening at all this kernel release, which is
  nice to see"

* tag 'driver-core-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  bus: subsys: update return type of ->remove_dev() to void
  driver core: correct device's shutdown order
  driver core: fix docbook for device_private.device
  selftests: firmware: skip timeout checks for kernels without user mode helper
  kernel, cpu: Remove bogus __ref annotations
  cpu: Remove bogus __ref annotation of cpu_subsys_online()
  firmware: fix wrong memory deallocation in fw_add_devm_name()
  sysfs.txt: update show method notes about sprintf/snprintf/scnprintf usage
  devres: fix devres_get()
2015-08-31 08:47:40 -07:00
Ingo Molnar
9b9412dc70 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU changes from Paul E. McKenney:

  - The combination of tree geometry-initialization simplifications
    and OS-jitter-reduction changes to expedited grace periods.
    These two are stacked due to the large number of conflicts
    that would otherwise result.

    [ With one addition, a temporary commit to silence a lockdep false
      positive. Additional changes to the expedited grace-period
      primitives (queued for 4.4) remove the cause of this false
      positive, and therefore include a revert of this temporary commit. ]

  - Documentation updates.

  - Torture-test updates.

  - Miscellaneous fixes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 12:12:12 +02:00
Mathias Krause
71cf5aeeb8 kernel, cpu: Remove bogus __ref annotations
cpu_chain lost its __cpuinitdata annotation long ago in commit
5c113fbeed ("fix cpu_chain section mismatch..."). This and the global
__cpuinit annotation drop in v3.11 vanished the need to mark all users,
including transitive ones, with the __ref annotation. Just get rid of it
to not wrongly hide section mismatches.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 15:18:26 -07:00
Vitaly Kuznetsov
32145c4677 cpu-hotplug: export cpu_hotplug_enable/cpu_hotplug_disable
Hyper-V module needs to disable cpu hotplug (offlining) as there is no
support from hypervisor side to reassign already opened event channels
to a different CPU. Currently it is been done by altering
smp_ops.cpu_disable but it is hackish.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:46:44 -07:00
Vitaly Kuznetsov
89af7ba574 cpu-hotplug: convert cpu_hotplug_disabled to a counter
As a prerequisite to exporting cpu_hotplug_enable/cpu_hotplug_disable
functions to modules we need to convert cpu_hotplug_disabled to a counter
to properly support disable -> disable -> enable call sequences. E.g.
after Hyper-V vmbus module (which is supposed to be the first user of
exported cpu_hotplug_enable/cpu_hotplug_disable) did cpu_hotplug_disable()
hibernate path calls disable_nonboot_cpus() and if we hit an error in
_cpu_down() enable_nonboot_cpus() will be called on the failure path (thus
making cpu_hotplug_disabled = 0 and leaving cpu hotplug in 'enabled'
state). Same problem is possible if more than 1 module use
cpu_hotplug_disable/cpu_hotplug_enable on their load/unload paths. When
one of these modules is been unloaded it is logical to leave cpu hotplug
in 'disabled' state.

To support the change we need to increse cpu_hotplug_disabled counter
in disable_nonboot_cpus() unconditionally as all users of
disable_nonboot_cpus() are supposed to do enable_nonboot_cpus() in case
an error was returned.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:46:44 -07:00
Oleg Nesterov
7eeb088e72 stop_machine: Unexport __stop_machine()
The only caller outside of stop_machine.c is _cpu_down(), it can use
stop_machine(). get_online_cpus() is fine under cpu_hotplug_begin().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: der.herr@hofr.at
Cc: paulmck@linux.vnet.ibm.com
Cc: riel@redhat.com
Cc: viro@ZenIV.linux.org.uk
Link: http://lkml.kernel.org/r/20150630012951.GA23934@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03 12:21:26 +02:00
Paul E. McKenney
779de6ce54 cpu: Wait for RCU grace periods concurrently
In kernels built with CONFIG_PREEMPT, _cpu_down() waits for RCU and
RCU-sched grace periods back-to-back, incurring quite a bit more latency
than required.  This commit therefore uses the new synchronize_rcu_mult()
to allow waiting for both grace periods concurrently.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-07-22 15:27:30 -07:00
Thomas Gleixner
ce0d3c0a6f genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now
Boris reported that the sparse_irq protection around __cpu_up() in the
generic code causes a regression on Xen. Xen allocates interrupts and
some more in the xen_cpu_up() function, so it deadlocks on the
sparse_irq_lock.

There is no simple fix for this and we really should have the
protection for all architectures, but for now the only solution is to
move it to x86 where actual wreckage due to the lack of protection has
been observed.

Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Fixes: a899418167 'hotplug: Prevent alloc/free of irq descriptors during cpu up/down'
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>
2015-07-15 10:39:17 +02:00
Thomas Gleixner
a899418167 hotplug: Prevent alloc/free of irq descriptors during cpu up/down
When a cpu goes up some architectures (e.g. x86) have to walk the irq
space to set up the vector space for the cpu. While this needs extra
protection at the architecture level we can avoid a few race
conditions by preventing the concurrent allocation/free of irq
descriptors and the associated data.

When a cpu goes down it moves the interrupts which are targeted to
this cpu away by reassigning the affinities. While this happens
interrupts can be allocated and freed, which opens a can of race
conditions in the code which reassignes the affinities because
interrupt descriptors might be freed underneath.

Example:

CPU1				CPU2
cpu_up/down
 irq_desc = irq_to_desc(irq);
				remove_from_radix_tree(desc);
 raw_spin_lock(&desc->lock);
				free(desc);

We could protect the irq descriptors with RCU, but that would require
a full tree change of all accesses to interrupt descriptors. But
fortunately these kind of race conditions are rather limited to a few
things like cpu hotplug. The normal setup/teardown is very well
serialized. So the simpler and obvious solution is:

Prevent allocation and freeing of interrupt descriptors accross cpu
hotplug.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Link: http://lkml.kernel.org/r/20150705171102.063519515@linutronix.de
2015-07-08 11:32:25 +02:00
Paul Gortmaker
927da9dfd1 cpu: Remove new instance of __cpuinit that crept back in
We removed __cpuinit support (leaving no-op stubs) quite some time ago.
However a new instance was added in commit 00df35f991
("cpu: Defer smpboot kthread unparking until CPU known to scheduler")

Since we want to clobber the stubs soon, get this removed now.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:39 -07:00
Paul E. McKenney
64eaf97421 cpu: Handle smpboot_unpark_threads() uniformly
Commit 00df35f991 (cpu: Defer smpboot kthread unparking until CPU known
to scheduler) put the online path's call to smpboot_unpark_threads()
into a CPU-hotplug notifier.  This commit places the offline-failure
paths call into the same notifier for the sake of uniformity.

Note that it is not currently possible to place the offline path's call to
smpboot_park_threads() into an existing notifier because the CPU_DYING
notifiers run in a restricted environment, and the CPU_UP_PREPARE
notifiers run too soon.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:39 -07:00
Linus Torvalds
078838d565 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU changes from Ingo Molnar:
 "The main changes in this cycle were:

   - changes permitting use of call_rcu() and friends very early in
     boot, for example, before rcu_init() is invoked.

   - add in-kernel API to enable and disable expediting of normal RCU
     grace periods.

   - improve RCU's handling of (hotplug-) outgoing CPUs.

   - NO_HZ_FULL_SYSIDLE fixes.

   - tiny-RCU updates to make it more tiny.

   - documentation updates.

   - miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  cpu: Provide smpboot_thread_init() on !CONFIG_SMP kernels as well
  cpu: Defer smpboot kthread unparking until CPU known to scheduler
  rcu: Associate quiescent-state reports with grace period
  rcu: Yet another fix for preemption and CPU hotplug
  rcu: Add diagnostics to grace-period cleanup
  rcutorture: Default to grace-period-initialization delays
  rcu: Handle outgoing CPUs on exit from idle loop
  cpu: Make CPU-offline idle-loop transition point more precise
  rcu: Eliminate ->onoff_mutex from rcu_node structure
  rcu: Process offlining and onlining only at grace-period start
  rcu: Move rcu_report_unblock_qs_rnp() to common code
  rcu: Rework preemptible expedited bitmask handling
  rcu: Remove event tracing from rcu_cpu_notify(), used by offline CPUs
  rcutorture: Enable slow grace-period initializations
  rcu: Provide diagnostic option to slow down grace-period initialization
  rcu: Detect stalls caused by failure to propagate up rcu_node tree
  rcu: Eliminate empty HOTPLUG_CPU ifdef
  rcu: Simplify sync_rcu_preempt_exp_init()
  rcu: Put all orphan-callback-related code under same comment
  rcu: Consolidate offline-CPU callback initialization
  ...
2015-04-14 13:36:04 -07:00
Paul E. McKenney
00df35f991 cpu: Defer smpboot kthread unparking until CPU known to scheduler
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:

  2a442c9c64 ("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>
2015-04-13 08:25:16 +02:00
Thomas Gleixner
a49b116dcb clockevents: Cleanup dead cpu explicitely
clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call. We are way better off to have explicit
calls instead of this monstrosity.

Split out the cleanup function for a dead cpu and invoke it
directly from the cpu down code. Make it conditional on
CPU_HOTPLUG as well.

Temporary change, will be refined in the future.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Rebased, added clockevents_notify() removal ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:44:37 +02:00
Thomas Gleixner
52c063d1ad clockevents: Make tick handover explicit
clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call. We are way better off to have explicit
calls instead of this monstrosity.

Split out the tick_handover call and invoke it explicitely from
the hotplug code. Temporary solution will be cleaned up in later
patches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:44:36 +02:00
Preeti U Murthy
345527b1ed clockevents: Fix cpu_down() race for hrtimer based broadcasting
It was found when doing a hotplug stress test on POWER, that the
machine either hit softlockups or rcu_sched stall warnings.  The
issue was traced to commit:

  7cba160ad7 ("powernv/cpuidle: Redesign idle states management")

which exposed the cpu_down() race with hrtimer based broadcast mode:

  5d1638acb9 ("tick: Introduce hrtimer based broadcast")

The race is the following:

Assume CPU1 is the CPU which holds the hrtimer broadcasting duty
before it is taken down.

	CPU0					CPU1

	cpu_down()				take_cpu_down()
						disable_interrupts()

	cpu_die()

	while (CPU1 != CPU_DEAD) {
		msleep(100);
		switch_to_idle();
		stop_cpu_timer();
		schedule_broadcast();
	}

	tick_cleanup_cpu_dead()
		take_over_broadcast()

So after CPU1 disabled interrupts it cannot handle the broadcast
hrtimer anymore, so CPU0 will be stuck forever.

Fix this by explicitly taking over broadcast duty before cpu_die().

This is a temporary workaround. What we really want is a callback
in the clockevent device which allows us to do that from the dying
CPU by pushing the hrtimer onto a different cpu. That might involve
an IPI and is definitely more complex than this immediate fix.

Changelog was picked up from:

    https://lkml.org/lkml/2015/2/16/213

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: nicolas.pitre@linaro.org
Cc: peterz@infradead.org
Cc: rjw@rjwysocki.net
Fixes: http://linuxppc.10917.n7.nabble.com/offlining-cpus-breakage-td88619.html
Link: http://lkml.kernel.org/r/20150330092410.24979.59887.stgit@preeti.in.ibm.com
[ Merged it to the latest timer tree, renamed the callback, tidied up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02 14:25:39 +02:00
Paul E. McKenney
528a25b00e cpu: Make CPU-offline idle-loop transition point more precise
This commit uses a per-CPU variable to make the CPU-offline code path
through the idle loop more precise, so that the outgoing CPU is
guaranteed to make it into the idle loop before it is powered off.
This commit is in preparation for putting the RCU offline-handling
code on this code path, which will eliminate the magic one-jiffy
wait that RCU uses as the maximum time for an outgoing CPU to get
all the way through the scheduler.

The magic one-jiffy wait for incoming CPUs remains a separate issue.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-03-12 15:19:37 -07:00
David Hildenbrand
87af9e7ff9 hotplugcpu: Avoid deadlocks by waking active_writer
Commit b2c4623dcd ("rcu: More on deadlock between CPU hotplug and expedited
grace periods") introduced another problem that can easily be reproduced by
starting/stopping cpus in a loop.

E.g.:
  for i in `seq 5000`; do
      echo 1 > /sys/devices/system/cpu/cpu1/online
      echo 0 > /sys/devices/system/cpu/cpu1/online
  done

Will result in:
  INFO: task /cpu_start_stop:1 blocked for more than 120 seconds.
  Call Trace:
  ([<00000000006a028e>] __schedule+0x406/0x91c)
   [<0000000000130f60>] cpu_hotplug_begin+0xd0/0xd4
   [<0000000000130ff6>] _cpu_up+0x3e/0x1c4
   [<0000000000131232>] cpu_up+0xb6/0xd4
   [<00000000004a5720>] device_online+0x80/0xc0
   [<00000000004a57f0>] online_store+0x90/0xb0
  ...

And a deadlock.

Problem is that if the last ref in put_online_cpus() can't get the
cpu_hotplug.lock the puts_pending count is incremented, but a sleeping
active_writer might never be woken up, therefore never exiting the loop in
cpu_hotplug_begin().

This fix removes puts_pending and turns refcount into an atomic variable. We
also introduce a wait queue for the active_writer, to avoid possible races and
use-after-free. There is no need to take the lock in put_online_cpus() anymore.

Can't reproduce it with this fix.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-06 11:01:14 -08:00
Paul E. McKenney
62db99f478 cpu: Avoid puts_pending overflow
A long string of get_online_cpus() with each followed by a
put_online_cpu() that fails to acquire cpu_hotplug.lock can result in
overflow of the cpu_hotplug.puts_pending counter.  Although this is
perhaps improbably, a system with absolutely no CPU-hotplug operations
will have an arbitrarily long time in which this overflow could occur.
This commit therefore adds overflow checks to get_online_cpus() and
try_get_online_cpus().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03 19:21:01 -08:00
Paul E. McKenney
b2c4623dcd rcu: More on deadlock between CPU hotplug and expedited grace periods
Commit dd56af42bd (rcu: Eliminate deadlock between CPU hotplug and
expedited grace periods) was incomplete.  Although it did eliminate
deadlocks involving synchronize_sched_expedited()'s acquisition of
cpu_hotplug.lock via get_online_cpus(), it did nothing about the similar
deadlock involving acquisition of this same lock via put_online_cpus().
This deadlock became apparent with testing involving hibernation.

This commit therefore changes put_online_cpus() acquisition of this lock
to be conditional, and increments a new cpu_hotplug.puts_pending field
in case of acquisition failure.  Then cpu_hotplug_begin() checks for this
new field being non-zero, and applies any changes to cpu_hotplug.refcount.

Reported-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Tested-by: Borislav Petkov <bp@suse.de>
2014-10-23 07:51:17 -07:00
Paul E. McKenney
dd56af42bd rcu: Eliminate deadlock between CPU hotplug and expedited grace periods
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>
2014-09-18 16:22:27 -07:00
Kirill Tkhai
b728ca0602 sched: Rework check_for_tasks()
1) Iterate thru all of threads in the system.
   Check for all threads, not only for group leaders.

2) Check for p->on_rq instead of p->state and cputime.
   Preempted task in !TASK_RUNNING state  OR just
   created task may be queued, that we want to be
   reported too.

3) Use read_lock() instead of write_lock().
   This function does not change any structures, and
   read_lock() is enough.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Cc: Konstantin Khorenko <khorenko@parallels.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Turner <pjt@google.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Todd E Brandt <todd.e.brandt@linux.intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1403684395.3462.44.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-05 11:17:45 +02:00
Linus Torvalds
19c1940fea More ACPI and power management updates for 3.16-rc1
- I didn't remember correctly that the Hans de Goede's ACPI video
    patches actually didn't flip the video.use_native_backlight
    default, although we had discussed that and decided to do that.
    Since I said we would do that in the previous PM+ACPI pull
    request, make that change for real now.
 
  - ACPI bus check notifications for PCI host bridges don't cause
    the bus below the host bridge to be checked for changes as they
    should because of a mistake in the ACPI-based PCI hotplug (ACPIPHP)
    subsystem that forgets to add hotplug contexts to PCI host bridge
    ACPI device objects.  Create hotplug contexts for PCI host bridges
    too as appropriate.
 
  - Revert recent cpufreq commit related to the big.LITTLE cpufreq
    driver that breaks arm64 builds.
 
  - Fix for a regression in the ppc-corenet cpufreq driver introduced
    during the 3.15 cycle and causing the driver to use the remainder
    from do_div instead of the quotient.  From Ed Swarthout.
 
  - Resets triggered by panic activate a BUG_ON() in vmalloc.c on
    systems where the ACPI reset register is located in memory address
    space.  Fix from Randy Wright.
 
  - Fix for a problem with cpufreq governors that decisions made by
    them may be suboptimal due to the fact that deferrable timers are
    used by them for CPU load sampling.  From Srivatsa S Bhat.
 
  - Fix for a problem with the Tegra cpufreq driver where the CPU
    frequency is temporarily switched to a "stable" level that
    is different from both the initial and target frequencies
    during transitions which causes udelay() to expire earlier than
    it should sometimes.  From Viresh Kumar.
 
  - New trace points and rework of some existing trace points for
    system suspend/resume profiling from Todd Brandt.
 
  - Assorted cpufreq fixes and cleanups from Stratos Karafotis and
    Viresh Kumar.
 
  - Copyright notice update for suspend-and-cpuhotplug.txt from
    Srivatsa S Bhat.
 
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Merge tag 'pm+acpi-3.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are fixups on top of the previous PM+ACPI pull request,
  regression fixes (ACPI hotplug, cpufreq ppc-corenet), other bug fixes
  (ACPI reset, cpufreq), new PM trace points for system suspend
  profiling and a copyright notice update.

  Specifics:

   - I didn't remember correctly that the Hans de Goede's ACPI video
     patches actually didn't flip the video.use_native_backlight
     default, although we had discussed that and decided to do that.
     Since I said we would do that in the previous PM+ACPI pull request,
     make that change for real now.

   - ACPI bus check notifications for PCI host bridges don't cause the
     bus below the host bridge to be checked for changes as they should
     because of a mistake in the ACPI-based PCI hotplug (ACPIPHP)
     subsystem that forgets to add hotplug contexts to PCI host bridge
     ACPI device objects.  Create hotplug contexts for PCI host bridges
     too as appropriate.

   - Revert recent cpufreq commit related to the big.LITTLE cpufreq
     driver that breaks arm64 builds.

   - Fix for a regression in the ppc-corenet cpufreq driver introduced
     during the 3.15 cycle and causing the driver to use the remainder
     from do_div instead of the quotient.  From Ed Swarthout.

   - Resets triggered by panic activate a BUG_ON() in vmalloc.c on
     systems where the ACPI reset register is located in memory address
     space.  Fix from Randy Wright.

   - Fix for a problem with cpufreq governors that decisions made by
     them may be suboptimal due to the fact that deferrable timers are
     used by them for CPU load sampling.  From Srivatsa S Bhat.

   - Fix for a problem with the Tegra cpufreq driver where the CPU
     frequency is temporarily switched to a "stable" level that is
     different from both the initial and target frequencies during
     transitions which causes udelay() to expire earlier than it should
     sometimes.  From Viresh Kumar.

   - New trace points and rework of some existing trace points for
     system suspend/resume profiling from Todd Brandt.

   - Assorted cpufreq fixes and cleanups from Stratos Karafotis and
     Viresh Kumar.

   - Copyright notice update for suspend-and-cpuhotplug.txt from
     Srivatsa S Bhat"

* tag 'pm+acpi-3.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / hotplug / PCI: Add hotplug contexts to PCI host bridges
  PM / sleep: trace events for device PM callbacks
  cpufreq: cpufreq-cpu0: remove dependency on THERMAL and REGULATOR
  cpufreq: tegra: update comment for clarity
  cpufreq: intel_pstate: Remove duplicate CPU ID check
  cpufreq: Mark CPU0 driver with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag
  PM / Documentation: Update copyright in suspend-and-cpuhotplug.txt
  cpufreq: governor: remove copy_prev_load from 'struct cpu_dbs_common_info'
  cpufreq: governor: Be friendly towards latency-sensitive bursty workloads
  PM / sleep: trace events for suspend/resume
  cpufreq: ppc-corenet-cpu-freq: do_div use quotient
  Revert "cpufreq: Enable big.LITTLE cpufreq driver on arm64"
  cpufreq: Tegra: implement intermediate frequency callbacks
  cpufreq: add support for intermediate (stable) frequencies
  ACPI / video: Change the default for video.use_native_backlight to 1
  ACPI: Fix bug when ACPI reset register is implemented in system memory
2014-06-12 13:14:19 -07:00
Rafael J. Wysocki
d715a226b0 Merge branch 'pm-sleep'
* pm-sleep:
  PM / sleep: trace events for device PM callbacks
  PM / sleep: trace events for suspend/resume
2014-06-12 13:43:08 +02:00
Todd E Brandt
bb3632c610 PM / sleep: trace events for suspend/resume
Adds trace events that give finer resolution into suspend/resume. These
events are graphed in the timelines generated by the analyze_suspend.py
script. They represent large areas of time consumed that are typical to
suspend and resume.

The event is triggered by calling the function "trace_suspend_resume"
with three arguments: a string (the name of the event to be displayed
in the timeline), an integer (case specific number, such as the power
state or cpu number), and a boolean (where true is used to denote the start
of the timeline event, and false to denote the end).

The suspend_resume trace event reproduces the data that the machine_suspend
trace event did, so the latter has been removed.

Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-07 00:18:07 +02:00
Fabian Frederick
84117da5b7 kernel/cpu.c: convert printk to pr_foo()
no level printk converted to pr_warn (if err)
no level printk converted to pr_info (disabling non-boot cpus)
Other printk converted to respective level.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:14 -07:00
Lai Jiangshan
6acbfb9697 sched: Fix hotplug vs. set_cpus_allowed_ptr()
Lai found that:

  WARNING: CPU: 1 PID: 13 at arch/x86/kernel/smp.c:124 native_smp_send_reschedule+0x2d/0x4b()
  ...
  migration_cpu_stop+0x1d/0x22

was caused by set_cpus_allowed_ptr() assuming that cpu_active_mask is
always a sub-set of cpu_online_mask.

This isn't true since 5fbd036b55 ("sched: Cleanup cpu_active madness").

So set active and online at the same time to avoid this particular
problem.

Fixes: 5fbd036b55 ("sched: Cleanup cpu_active madness")
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael wang <wangyun@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/53758B12.8060609@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 10:21:31 +02:00
Srivatsa S. Bhat
93ae4f978c CPU hotplug: Provide lockless versions of callback registration functions
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>
2014-03-20 13:43:40 +01:00
Gautham R. Shenoy
a19423b987 CPU hotplug: Add lockdep annotations to get/put_online_cpus()
Add lockdep annotations for get/put_online_cpus() and
cpu_hotplug_begin()/cpu_hotplug_end().

Cc: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-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>
2014-03-20 13:43:40 +01:00
Linus Torvalds
fe8a45df36 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Four bugfixes and one performance fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Avoid integer overflow
  sched: Optimize task_sched_runtime()
  sched/numa: Cure update_numa_stats() vs. hotplug
  sched/numa: Fix NULL pointer dereference in task_numa_migrate()
  sched: Fix endless sync_sched/rcu() loop inside _cpu_down()
2013-11-14 16:55:11 +09:00
Michael wang
106dd5afde sched: Fix endless sync_sched/rcu() loop inside _cpu_down()
Commit 6acce3ef8:

	sched: Remove get_online_cpus() usage

tries to do sync_sched/rcu() inside _cpu_down() but triggers:

	INFO: task swapper/0:1 blocked for more than 120 seconds.
	...
	[<ffffffff811263dc>] synchronize_rcu+0x2c/0x30
	[<ffffffff81d1bd82>] _cpu_down+0x2b2/0x340
	...

It was caused by that in the rcu boost case we rely on smpboot thread to
finish the rcu callback, which has already been parked before sync in here
and leads to the endless sync_sched/rcu().

This patch exchanges the sequence of smpboot_park_threads() and
sync_sched/rcu() to fix the bug.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5282EDC0.6060003@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:33:50 +01:00
Toshi Kani
01b0f19707 cpu/mem hotplug: add try_online_node() for cpu_up()
cpu_up() has #ifdef CONFIG_MEMORY_HOTPLUG code blocks, which call
mem_online_node() to put its node online if offlined and then call
build_all_zonelists() to initialize the zone list.

These steps are specific to memory hotplug, and should be managed in
mm/memory_hotplug.c.  lock_memory_hotplug() should also be held for the
whole steps.

For this reason, this patch replaces mem_online_node() with
try_online_node(), which performs the whole steps with
lock_memory_hotplug() held.  try_online_node() is named after
try_offline_node() as they have similar purpose.

There is no functional change in this patch.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Peter Zijlstra
6acce3ef84 sched: Remove get_online_cpus() usage
Remove get_online_cpus() usage from the scheduler; there's 4 sites that
use it:

 - sched_init_smp(); where its completely superfluous since we're in
   'early' boot and there simply cannot be any hotplugging.

 - sched_getaffinity(); we already take a raw spinlock to protect the
   task cpus_allowed mask, this disables preemption and therefore
   also stabilizes cpu_online_mask as that's modified using
   stop_machine. However switch to active mask for symmetry with
   sched_setaffinity()/set_cpus_allowed_ptr(). We guarantee active
   mask stability by inserting sync_rcu/sched() into _cpu_down.

 - sched_setaffinity(); we don't appear to need get_online_cpus()
   either, there's two sites where hotplug appears relevant:
    * cpuset_cpus_allowed(); for the !cpuset case we use possible_mask,
      for the cpuset case we hold task_lock, which is a spinlock and
      thus for mainline disables preemption (might cause pain on RT).
    * set_cpus_allowed_ptr(); Holds all scheduler locks and thus has
      preemption properly disabled; also it already deals with hotplug
      races explicitly where it releases them.

 - migrate_swap(); we can make stop_two_cpus() do the heavy lifting for
   us with a little trickery. By adding a sync_sched/rcu() after the
   CPU_DOWN_PREPARE notifier we can provide preempt/rcu guarantees for
   cpu_active_mask. Use these to validate that both our cpus are active
   when queueing the stop work before we queue the stop_machine works
   for take_cpu_down().

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20131011123820.GV3081@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-16 14:22:16 +02:00
Toshi Kani
b9d10be7a8 ACPI / processor: Acquire writer lock to update CPU maps
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>
2013-08-13 12:20:16 +02:00
Paul Gortmaker
0db0628d90 kernel: delete __cpuinit usage from all core kernel files
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>
2013-07-14 19:36:59 -04:00
Srivatsa S. Bhat
16e53dbf10 CPU hotplug: provide a generic helper to disable/enable CPU hotplug
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>
2013-06-12 16:29:44 -07:00