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320 commits

Author SHA1 Message Date
Trilok Soni
5ab1e18aa3 Revert "Merge remote-tracking branch 'msm-4.4/tmp-510d0a3f' into msm-4.4"
This reverts commit 9d6fd2c3e9 ("Merge remote-tracking branch
'msm-4.4/tmp-510d0a3f' into msm-4.4"), because it breaks the
dump parsing tools due to kernel can be loaded anywhere in the memory
now and not fixed at linear mapping.

Change-Id: Id416f0a249d803442847d09ac47781147b0d0ee6
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
2016-08-26 14:34:05 -07:00
Trilok Soni
9d6fd2c3e9 Merge remote-tracking branch 'msm-4.4/tmp-510d0a3f' into msm-4.4
* msm-4.4/tmp-510d0a3f:
  Linux 4.4.11
  nf_conntrack: avoid kernel pointer value leak in slab name
  drm/radeon: fix DP link training issue with second 4K monitor
  drm/i915/bdw: Add missing delay during L3 SQC credit programming
  drm/i915: Bail out of pipe config compute loop on LPT
  drm/radeon: fix PLL sharing on DCE6.1 (v2)
  Revert "[media] videobuf2-v4l2: Verify planes array in buffer dequeueing"
  Input: max8997-haptic - fix NULL pointer dereference
  get_rock_ridge_filename(): handle malformed NM entries
  tools lib traceevent: Do not reassign parg after collapse_tree()
  qla1280: Don't allocate 512kb of host tags
  atomic_open(): fix the handling of create_error
  regulator: axp20x: Fix axp22x ldo_io voltage ranges
  regulator: s2mps11: Fix invalid selector mask and voltages for buck9
  workqueue: fix rebind bound workers warning
  ARM: dts: at91: sam9x5: Fix the memory range assigned to the PMC
  vfs: rename: check backing inode being equal
  vfs: add vfs_select_inode() helper
  perf/core: Disable the event on a truncated AUX record
  regmap: spmi: Fix regmap_spmi_ext_read in multi-byte case
  pinctrl: at91-pio4: fix pull-up/down logic
  spi: spi-ti-qspi: Handle truncated frames properly
  spi: spi-ti-qspi: Fix FLEN and WLEN settings if bits_per_word is overridden
  spi: pxa2xx: Do not detect number of enabled chip selects on Intel SPT
  ALSA: hda - Fix broken reconfig
  ALSA: hda - Fix white noise on Asus UX501VW headset
  ALSA: hda - Fix subwoofer pin on ASUS N751 and N551
  ALSA: usb-audio: Yet another Phoneix Audio device quirk
  ALSA: usb-audio: Quirk for yet another Phoenix Audio devices (v2)
  crypto: testmgr - Use kmalloc memory for RSA input
  crypto: hash - Fix page length clamping in hash walk
  crypto: qat - fix invalid pf2vf_resp_wq logic
  s390/mm: fix asce_bits handling with dynamic pagetable levels
  zsmalloc: fix zs_can_compact() integer overflow
  ocfs2: fix posix_acl_create deadlock
  ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang
  net/route: enforce hoplimit max value
  tcp: refresh skb timestamp at retransmit time
  net: thunderx: avoid exposing kernel stack
  net: fix a kernel infoleak in x25 module
  uapi glibc compat: fix compile errors when glibc net/if.h included before linux/if.h MIME-Version: 1.0
  bridge: fix igmp / mld query parsing
  net: bridge: fix old ioctl unlocked net device walk
  VSOCK: do not disconnect socket when peer has shutdown SEND only
  net/mlx4_en: Fix endianness bug in IPV6 csum calculation
  net: fix infoleak in rtnetlink
  net: fix infoleak in llc
  net: fec: only clear a queue's work bit if the queue was emptied
  netem: Segment GSO packets on enqueue
  sch_dsmark: update backlog as well
  sch_htb: update backlog as well
  net_sched: update hierarchical backlog too
  net_sched: introduce qdisc_replace() helper
  gre: do not pull header in ICMP error processing
  net: Implement net_dbg_ratelimited() for CONFIG_DYNAMIC_DEBUG case
  samples/bpf: fix trace_output example
  bpf: fix check_map_func_compatibility logic
  bpf: fix refcnt overflow
  bpf: fix double-fdput in replace_map_fd_with_map_ptr()
  net/mlx4_en: fix spurious timestamping callbacks
  ipv4/fib: don't warn when primary address is missing if in_dev is dead
  net/mlx5e: Fix minimum MTU
  net/mlx5e: Device's mtu field is u16 and not int
  openvswitch: use flow protocol when recalculating ipv6 checksums
  atl2: Disable unimplemented scatter/gather feature
  vlan: pull on __vlan_insert_tag error path and fix csum correction
  net: use skb_postpush_rcsum instead of own implementations
  cdc_mbim: apply "NDP to end" quirk to all Huawei devices
  bpf/verifier: reject invalid LD_ABS | BPF_DW instruction
  net: sched: do not requeue a NULL skb
  packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface
  route: do not cache fib route info on local routes with oif
  decnet: Do not build routes to devices without decnet private data.
  parisc: Use generic extable search and sort routines
  arm64: kasan: Use actual memory node when populating the kernel image shadow
  arm64: mm: treat memstart_addr as a signed quantity
  arm64: lse: deal with clobbered IP registers after branch via PLT
  arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
  arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
  arm64: consistently use p?d_set_huge
  arm64: fix KASLR boot-time I-cache maintenance
  arm64: hugetlb: partial revert of 66b3923a1a0f
  arm64: make irq_stack_ptr more robust
  arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomness
  efi: stub: use high allocation for converted command line
  efi: stub: add implementation of efi_random_alloc()
  efi: stub: implement efi_get_random_bytes() based on EFI_RNG_PROTOCOL
  arm64: kaslr: randomize the linear region
  arm64: add support for kernel ASLR
  arm64: add support for building vmlinux as a relocatable PIE binary
  arm64: switch to relative exception tables
  extable: add support for relative extables to search and sort routines
  scripts/sortextable: add support for ET_DYN binaries
  arm64: futex.h: Add missing PAN toggling
  arm64: make asm/elf.h available to asm files
  arm64: avoid dynamic relocations in early boot code
  arm64: avoid R_AARCH64_ABS64 relocations for Image header fields
  arm64: add support for module PLTs
  arm64: move brk immediate argument definitions to separate header
  arm64: mm: use bit ops rather than arithmetic in pa/va translations
  arm64: mm: only perform memstart_addr sanity check if DEBUG_VM
  arm64: User die() instead of panic() in do_page_fault()
  arm64: allow kernel Image to be loaded anywhere in physical memory
  arm64: defer __va translation of initrd_start and initrd_end
  arm64: move kernel image to base of vmalloc area
  arm64: kvm: deal with kernel symbols outside of linear mapping
  arm64: decouple early fixmap init from linear mapping
  arm64: pgtable: implement static [pte|pmd|pud]_offset variants
  arm64: introduce KIMAGE_VADDR as the virtual base of the kernel region
  arm64: add support for ioremap() block mappings
  arm64: prevent potential circular header dependencies in asm/bug.h
  of/fdt: factor out assignment of initrd_start/initrd_end
  of/fdt: make memblock minimum physical address arch configurable
  arm64: Remove the get_thread_info() function
  arm64: kernel: Don't toggle PAN on systems with UAO
  arm64: cpufeature: Test 'matches' pointer to find the end of the list
  arm64: kernel: Add support for User Access Override
  arm64: add ARMv8.2 id_aa64mmfr2 boiler plate
  arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro
  arm64: use local label prefixes for __reg_num symbols
  arm64: vdso: Mark vDSO code as read-only
  arm64: ubsan: select ARCH_HAS_UBSAN_SANITIZE_ALL
  arm64: ptdump: Indicate whether memory should be faulting
  arm64: Add support for ARCH_SUPPORTS_DEBUG_PAGEALLOC
  arm64: Drop alloc function from create_mapping
  arm64: prefetch: add missing #include for spin_lock_prefetch
  arm64: lib: patch in prfm for copy_page if requested
  arm64: lib: improve copy_page to deal with 128 bytes at a time
  arm64: prefetch: add alternative pattern for CPUs without a prefetcher
  arm64: prefetch: don't provide spin_lock_prefetch with LSE
  arm64: allow vmalloc regions to be set with set_memory_*
  arm64: kernel: implement ACPI parking protocol
  arm64: mm: create new fine-grained mappings at boot
  arm64: ensure _stext and _etext are page-aligned
  arm64: mm: allow passing a pgdir to alloc_init_*
  arm64: mm: allocate pagetables anywhere
  arm64: mm: use fixmap when creating page tables
  arm64: mm: add functions to walk tables in fixmap
  arm64: mm: add __{pud,pgd}_populate
  arm64: mm: avoid redundant __pa(__va(x))
  arm64: mm: add functions to walk page tables by PA
  arm64: mm: move pte_* macros
  arm64: kasan: avoid TLB conflicts
  arm64: mm: add code to safely replace TTBR1_EL1
  arm64: add function to install the idmap
  arm64: unmap idmap earlier
  arm64: unify idmap removal
  arm64: mm: place empty_zero_page in bss
  arm64: mm: specialise pagetable allocators
  asm-generic: Fix local variable shadow in __set_fixmap_offset
  Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules
  arm64: Fix an enum typo in mm/dump.c
  arm64: kasan: ensure that the KASAN zero page is mapped read-only
  arch/arm64/include/asm/pgtable.h: add pmd_mkclean for THP
  arm64: hide __efistub_ aliases from kallsyms
  Linux 4.4.10
  drm/i915/skl: Fix DMC load on Skylake J0 and K0
  lib/test-string_helpers.c: fix and improve string_get_size() tests
  ACPI / processor: Request native thermal interrupt handling via _OSC
  drm/i915: Fake HDMI live status
  drm/i915: Make RPS EI/thresholds multiple of 25 on SNB-BDW
  drm/i915: Fix eDP low vswing for Broadwell
  drm/i915/ddi: Fix eDP VDD handling during booting and suspend/resume
  drm/radeon: make sure vertical front porch is at least 1
  iio: ak8975: fix maybe-uninitialized warning
  iio: ak8975: Fix NULL pointer exception on early interrupt
  drm/amdgpu: set metadata pointer to NULL after freeing.
  drm/amdgpu: make sure vertical front porch is at least 1
  gpu: ipu-v3: Fix imx-ipuv3-crtc module autoloading
  nvmem: mxs-ocotp: fix buffer overflow in read
  USB: serial: cp210x: add Straizona Focusers device ids
  USB: serial: cp210x: add ID for Link ECU
  ata: ahci-platform: Add ports-implemented DT bindings.
  libahci: save port map for forced port map
  powerpc: Fix bad inline asm constraint in create_zero_mask()
  ACPICA: Dispatcher: Update thread ID for recursive method calls
  x86/sysfb_efi: Fix valid BAR address range check
  ARC: Add missing io barriers to io{read,write}{16,32}be()
  ARM: cpuidle: Pass on arm_cpuidle_suspend()'s return value
  propogate_mnt: Handle the first propogated copy being a slave
  fs/pnode.c: treat zero mnt_group_id-s as unequal
  x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO
  MAINTAINERS: Remove asterisk from EFI directory names
  writeback: Fix performance regression in wb_over_bg_thresh()
  batman-adv: Reduce refcnt of removed router when updating route
  batman-adv: Fix broadcast/ogm queue limit on a removed interface
  batman-adv: Check skb size before using encapsulated ETH+VLAN header
  batman-adv: fix DAT candidate selection (must use vid)
  mm: update min_free_kbytes from khugepaged after core initialization
  proc: prevent accessing /proc/<PID>/environ until it's ready
  Input: zforce_ts - fix dual touch recognition
  HID: Fix boot delay for Creative SB Omni Surround 5.1 with quirk
  HID: wacom: Add support for DTK-1651
  xen/evtchn: fix ring resize when binding new events
  xen/balloon: Fix crash when ballooning on x86 32 bit PAE
  xen: Fix page <-> pfn conversion on 32 bit systems
  ARM: SoCFPGA: Fix secondary CPU startup in thumb2 kernel
  ARM: EXYNOS: Properly skip unitialized parent clock in power domain on
  mm/zswap: provide unique zpool name
  mm, cma: prevent nr_isolated_* counters from going negative
  Minimal fix-up of bad hashing behavior of hash_64()
  MD: make bio mergeable
  tracing: Don't display trigger file for events that can't be enabled
  mac80211: fix statistics leak if dev_alloc_name() fails
  ath9k: ar5008_hw_cmn_spur_mitigate: add missing mask_m & mask_p initialisation
  lpfc: fix misleading indentation
  clk: qcom: msm8960: Fix ce3_src register offset
  clk: versatile: sp810: support reentrance
  clk: qcom: msm8960: fix ce3_core clk enable register
  clk: meson: Fix meson_clk_register_clks() signature type mismatch
  clk: rockchip: free memory in error cases when registering clock branches
  soc: rockchip: power-domain: fix err handle while probing
  clk-divider: make sure read-only dividers do not write to their register
  CNS3xxx: Fix PCI cns3xxx_write_config()
  mwifiex: fix corner case association failure
  ata: ahci_xgene: dereferencing uninitialized pointer in probe
  nbd: ratelimit error msgs after socket close
  mfd: intel-lpss: Remove clock tree on error path
  ipvs: drop first packet to redirect conntrack
  ipvs: correct initial offset of Call-ID header search in SIP persistence engine
  ipvs: handle ip_vs_fill_iph_skb_off failure
  RDMA/iw_cxgb4: Fix bar2 virt addr calculation for T4 chips
  Revert: "powerpc/tm: Check for already reclaimed tasks"
  arm64: head.S: use memset to clear BSS
  efi: stub: define DISABLE_BRANCH_PROFILING for all architectures
  arm64: entry: remove pointless SPSR mode check
  arm64: mm: move pgd_cache initialisation to pgtable_cache_init
  arm64: module: avoid undefined shift behavior in reloc_data()
  arm64: module: fix relocation of movz instruction with negative immediate
  arm64: traps: address fallout from printk -> pr_* conversion
  arm64: ftrace: fix a stack tracer's output under function graph tracer
  arm64: pass a task parameter to unwind_frame()
  arm64: ftrace: modify a stack frame in a safe way
  arm64: remove irq_count and do_softirq_own_stack()
  arm64: hugetlb: add support for PTE contiguous bit
  arm64: Use PoU cache instr for I/D coherency
  arm64: Defer dcache flush in __cpu_copy_user_page
  arm64: reduce stack use in irq_handler
  arm64: Documentation: add list of software workarounds for errata
  arm64: mm: place __cpu_setup in .text
  arm64: cmpxchg: Don't incldue linux/mmdebug.h
  arm64: mm: fold alternatives into .init
  arm64: Remove redundant padding from linker script
  arm64: mm: remove pointless PAGE_MASKing
  arm64: don't call C code with el0's fp register
  arm64: when walking onto the task stack, check sp & fp are in current->stack
  arm64: Add this_cpu_ptr() assembler macro for use in entry.S
  arm64: irq: fix walking from irq stack to task stack
  arm64: Add do_softirq_own_stack() and enable irq_stacks
  arm64: Modify stack trace and dump for use with irq_stack
  arm64: Store struct thread_info in sp_el0
  arm64: Add trace_hardirqs_off annotation in ret_to_user
  arm64: ftrace: fix the comments for ftrace_modify_code
  arm64: ftrace: stop using kstop_machine to enable/disable tracing
  arm64: spinlock: serialise spin_unlock_wait against concurrent lockers
  arm64: enable HAVE_IRQ_TIME_ACCOUNTING
  arm64: fix COMPAT_SHMLBA definition for large pages
  arm64: add __init/__initdata section marker to some functions/variables
  arm64: pgtable: implement pte_accessible()
  arm64: mm: allow sections for unaligned bases
  arm64: mm: detect bad __create_mapping uses
  Linux 4.4.9
  extcon: max77843: Use correct size for reading the interrupt register
  stm class: Select CONFIG_SRCU
  megaraid_sas: add missing curly braces in ioctl handler
  sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race
  thermal: rockchip: fix a impossible condition caused by the warning
  unbreak allmodconfig KCONFIG_ALLCONFIG=...
  jme: Fix device PM wakeup API usage
  jme: Do not enable NIC WoL functions on S0
  bus: imx-weim: Take the 'status' property value into account
  ARM: dts: pxa: fix dma engine node to pxa3xx-nand
  ARM: dts: armada-375: use armada-370-sata for SATA
  ARM: EXYNOS: select THERMAL_OF
  ARM: prima2: always enable reset controller
  ARM: OMAP3: Add cpuidle parameters table for omap3430
  ext4: fix races of writeback with punch hole and zero range
  ext4: fix races between buffered IO and collapse / insert range
  ext4: move unlocked dio protection from ext4_alloc_file_blocks()
  ext4: fix races between page faults and hole punching
  perf stat: Document --detailed option
  perf tools: handle spaces in file names obtained from /proc/pid/maps
  perf hists browser: Only offer symbol scripting when a symbol is under the cursor
  mtd: nand: Drop mtd.owner requirement in nand_scan
  mtd: brcmnand: Fix v7.1 register offsets
  mtd: spi-nor: remove micron_quad_enable()
  serial: sh-sci: Remove cpufreq notifier to fix crash/deadlock
  ext4: fix NULL pointer dereference in ext4_mark_inode_dirty()
  x86/mm/kmmio: Fix mmiotrace for hugepages
  perf evlist: Reference count the cpu and thread maps at set_maps()
  drivers/misc/ad525x_dpot: AD5274 fix RDAC read back errors
  rtc: max77686: Properly handle regmap_irq_get_virq() error code
  rtc: rx8025: remove rv8803 id
  rtc: ds1685: passing bogus values to irq_restore
  rtc: vr41xx: Wire up alarm_irq_enable
  rtc: hym8563: fix invalid year calculation
  PM / Domains: Fix removal of a subdomain
  PM / OPP: Initialize u_volt_min/max to a valid value
  misc: mic/scif: fix wrap around tests
  misc/bmp085: Enable building as a module
  lib/mpi: Endianness fix
  fbdev: da8xx-fb: fix videomodes of lcd panels
  scsi_dh: force modular build if SCSI is a module
  paride: make 'verbose' parameter an 'int' again
  regulator: s5m8767: fix get_register() error handling
  irqchip/mxs: Fix error check of of_io_request_and_map()
  irqchip/sunxi-nmi: Fix error check of of_io_request_and_map()
  spi/rockchip: Make sure spi clk is on in rockchip_spi_set_cs
  locking/mcs: Fix mcs_spin_lock() ordering
  regulator: core: Fix nested locking of supplies
  regulator: core: Ensure we lock all regulators
  regulator: core: fix regulator_lock_supply regression
  Revert "regulator: core: Fix nested locking of supplies"
  videobuf2-v4l2: Verify planes array in buffer dequeueing
  videobuf2-core: Check user space planes array in dqbuf
  USB: usbip: fix potential out-of-bounds write
  cgroup: make sure a parent css isn't freed before its children
  mm/hwpoison: fix wrong num_poisoned_pages accounting
  mm: vmscan: reclaim highmem zone if buffer_heads is over limit
  numa: fix /proc/<pid>/numa_maps for THP
  mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check
  memcg: relocate charge moving from ->attach to ->post_attach
  cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
  slub: clean up code for kmem cgroup support to kmem_cache_free_bulk
  workqueue: fix ghost PENDING flag while doing MQ IO
  x86/apic: Handle zero vector gracefully in clear_vector_irq()
  efi: Expose non-blocking set_variable() wrapper to efivars
  efi: Fix out-of-bounds read in variable_matches()
  IB/security: Restrict use of the write() interface
  IB/mlx5: Expose correct max_sge_rd limit
  cxl: Keep IRQ mappings on context teardown
  v4l2-dv-timings.h: fix polarity for 4k formats
  vb2-memops: Fix over allocation of frame vectors
  ASoC: rt5640: Correct the digital interface data select
  ASoC: dapm: Make sure we have a card when displaying component widgets
  ASoC: ssm4567: Reset device before regcache_sync()
  ASoC: s3c24xx: use const snd_soc_component_driver pointer
  EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback
  toshiba_acpi: Fix regression caused by hotkey enabling value
  i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared
  i2c: cpm: Fix build break due to incompatible pointer types
  perf intel-pt: Fix segfault tracing transactions
  drm/i915: Use fw_domains_put_with_fifo() on HSW
  drm/i915: Fixup the free space logic in ring_prepare
  drm/amdkfd: uninitialized variable in dbgdev_wave_control_set_registers()
  drm/i915: skl_update_scaler() wants a rotation bitmask instead of bit number
  drm/i915: Cleanup phys status page too
  pwm: brcmstb: Fix check of devm_ioremap_resource() return code
  drm/dp/mst: Get validated port ref in drm_dp_update_payload_part1()
  drm/dp/mst: Restore primary hub guid on resume
  drm/dp/mst: Validate port in drm_dp_payload_send_msg()
  drm/nouveau/gr/gf100: select a stream master to fixup tfb offset queries
  drm: Loongson-3 doesn't fully support wc memory
  drm/radeon: fix vertical bars appear on monitor (v2)
  drm/radeon: forbid mapping of userptr bo through radeon device file
  drm/radeon: fix initial connector audio value
  drm/radeon: add a quirk for a XFX R9 270X
  drm/amdgpu: fix regression on CIK (v2)
  amdgpu/uvd: add uvd fw version for amdgpu
  drm/amdgpu: bump the afmt limit for CZ, ST, Polaris
  drm/amdgpu: use defines for CRTCs and AMFT blocks
  drm/amdgpu: when suspending, if uvd/vce was running. need to cancel delay work.
  iommu/dma: Restore scatterlist offsets correctly
  iommu/amd: Fix checking of pci dma aliases
  pinctrl: single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs
  pinctrl: mediatek: correct debounce time unit in mtk_gpio_set_debounce
  xen kconfig: don't "select INPUT_XEN_KBDDEV_FRONTEND"
  Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay
  Input: gtco - fix crash on detecting device without endpoints
  netlink: don't send NETLINK_URELEASE for unbound sockets
  nl80211: check netlink protocol in socket release notification
  powerpc: Update TM user feature bits in scan_features()
  powerpc: Update cpu_user_features2 in scan_features()
  powerpc: scan_features() updates incorrect bits for REAL_LE
  crypto: talitos - fix AEAD tcrypt tests
  crypto: talitos - fix crash in talitos_cra_init()
  crypto: sha1-mb - use corrcet pointer while completing jobs
  crypto: ccp - Prevent information leakage on export
  iwlwifi: mvm: fix memory leak in paging
  iwlwifi: pcie: lower the debug level for RSA semaphore access
  s390/pci: add extra padding to function measurement block
  cpufreq: intel_pstate: Fix processing for turbo activation ratio
  Revert "drm/amdgpu: disable runtime pm on PX laptops without dGPU power control"
  Revert "drm/radeon: disable runtime pm on PX laptops without dGPU power control"
  drm/i915: Fix race condition in intel_dp_destroy_mst_connector()
  drm/qxl: fix cursor position with non-zero hotspot
  drm/nouveau/core: use vzalloc for allocating ramht
  futex: Acknowledge a new waiter in counter before plist
  futex: Handle unlock_pi race gracefully
  asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic()
  ALSA: hda - Add dock support for ThinkPad X260
  ALSA: pcxhr: Fix missing mutex unlock
  ALSA: hda - add PCI ID for Intel Broxton-T
  ALSA: hda - Keep powering up ADCs on Cirrus codecs
  ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m
  ALSA: hda - Don't trust the reported actual power state
  x86 EDAC, sb_edac.c: Repair damage introduced when "fixing" channel address
  x86/mm/xen: Suppress hugetlbfs in PV guests
  arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission
  arm64: Honour !PTE_WRITE in set_pte_at() for kernel mappings
  sched/cgroup: Fix/cleanup cgroup teardown/init
  dmaengine: pxa_dma: fix the maximum requestor line
  dmaengine: hsu: correct use of channel status register
  dmaengine: dw: fix master selection
  debugfs: Make automount point inodes permanently empty
  lib: lz4: fixed zram with lz4 on big endian machines
  dm cache metadata: fix cmd_read_lock() acquiring write lock
  dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros
  usb: gadget: f_fs: Fix use-after-free
  usb: hcd: out of bounds access in for_each_companion
  xhci: fix 10 second timeout on removal of PCI hotpluggable xhci controllers
  usb: xhci: fix wild pointers in xhci_mem_cleanup
  xhci: resume USB 3 roothub first
  usb: xhci: applying XHCI_PME_STUCK_QUIRK to Intel BXT B0 host
  assoc_array: don't call compare_object() on a node
  ARM: OMAP2+: hwmod: Fix updating of sysconfig register
  ARM: OMAP2: Fix up interconnect barrier initialization for DRA7
  ARM: mvebu: Correct unit address for linksys
  ARM: dts: AM43x-epos: Fix clk parent for synctimer
  KVM: arm/arm64: Handle forward time correction gracefully
  kvm: x86: do not leak guest xcr0 into host interrupt handlers
  x86/mce: Avoid using object after free in genpool
  block: loop: fix filesystem corruption in case of aio/dio
  block: partition: initialize percpuref before sending out KOBJ_ADD

Conflicts:
	arch/arm64/Kconfig
	arch/arm64/include/asm/cputype.h
	arch/arm64/include/asm/hardirq.h
	arch/arm64/include/asm/irq.h
	arch/arm64/kernel/cpu_errata.c
	arch/arm64/kernel/cpuinfo.c
	arch/arm64/kernel/setup.c
	arch/arm64/kernel/smp.c
	arch/arm64/kernel/stacktrace.c
	arch/arm64/mm/init.c
	arch/arm64/mm/mmu.c
	arch/arm64/mm/pageattr.c
	mm/memcontrol.c

CRs-Fixed: 1054234
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
Change-Id: I2a7a34631ffee36ce18b9171f16d023be777392f
2016-08-18 14:50:45 -07:00
Howard Cochran
4bc9468f16 writeback: Fix performance regression in wb_over_bg_thresh()
commit 74d369443325063a5f0260e63971decb950fd8fa upstream.

Commit 947e9762a8 ("writeback: update wb_over_bg_thresh() to use
wb_domain aware operations") unintentionally changed this function's
meaning from "are there more dirty pages than the background writeback
threshold" to "are there more dirty pages than the writeback threshold".
The background writeback threshold is typically half of the writeback
threshold, so this had the effect of raising the number of dirty pages
required to cause a writeback worker to perform background writeout.

This can cause a very severe performance regression when a BDI uses
BDI_CAP_STRICTLIMIT because balance_dirty_pages() and the writeback worker
can now disagree on whether writeback should be initiated.

For example, in a system having 1GB of RAM, a single spinning disk, and a
"pass-through" FUSE filesystem mounted over the disk, application code
mmapped a 128MB file on the disk and was randomly dirtying pages in that
mapping.

Because FUSE uses strictlimit and has a default max_ratio of only 1%, in
balance_dirty_pages, thresh is ~200, bg_thresh is ~100, and the
dirty_freerun_ceiling is the average of those, ~150. So, it pauses the
dirtying processes when we have 151 dirty pages and wakes up a background
writeback worker. But the worker tests the wrong threshold (200 instead of
100), so it does not initiate writeback and just returns.

Thus, balance_dirty_pages keeps looping, sleeping and then waking up the
worker who will do nothing. It remains stuck in this state until the few
dirty pages that we have finally expire and we write them back for that
reason. Then the whole process repeats, resulting in near-zero throughput
through the FUSE BDI.

The fix is to call the parameterized variant of wb_calc_thresh, so that the
worker will do writeback if the bg_thresh is exceeded which was the
behavior before the referenced commit.

Fixes: 947e9762a8 ("writeback: update wb_over_bg_thresh() to use wb_domain aware operations")
Signed-off-by: Howard Cochran <hcochran@kernelspring.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-11 11:21:18 +02:00
Vinayak Menon
3086328d5f mm: page-writeback: fix page state calculation in throttle_vm_writeout
It was found that a number of tasks were blocked in the reclaim path
(throttle_vm_writeout) for seconds, because of vmstat_diff not being
synced in time. Fix that by adding a new function
global_page_state_snapshot.

Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Change-Id: Iec167635ad724a55c27bdbd49eb8686e7857216c
2016-03-22 11:03:54 -07:00
Peter Zijlstra
90eec103b9 treewide: Remove old email address
There were still a number of references to my old Red Hat email
address in the kernel source. Remove these while keeping the
Red Hat copyright notices intact.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23 09:44:58 +01:00
Yang Shi
50e55bf626 mm/page-writeback.c: initialize m_dirty to avoid compile warning
When building kernel with gcc 5.2, the below warning is raised:

  mm/page-writeback.c: In function 'balance_dirty_pages.isra.10':
  mm/page-writeback.c:1545:17: warning: 'm_dirty' may be used uninitialized in this function [-Wmaybe-uninitialized]
     unsigned long m_dirty, m_thresh, m_bg_thresh;

The m_dirty{thresh, bg_thresh} are initialized in the block of "if
(mdtc)", so if mdts is null, they won't be initialized before being used.
Initialize m_dirty to zero, also initialize m_thresh and m_bg_thresh to
keep consistency.

They are used later by if condition: !mdtc || m_dirty <=
dirty_freerun_ceiling(m_thresh, m_bg_thresh)

If mdtc is null, dirty_freerun_ceiling will not be called at all, so the
initialization will not change any behavior other than just ceasing the
compile warning.

(akpm: the patch actually reduces .text size by ~20 bytes on gcc-4.x.y)

[akpm@linux-foundation.org: add comment]
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20 16:17:32 -08:00
Tejun Heo
c5edf9cdc4 writeback: fix incorrect calculation of available memory for memcg domains
For memcg domains, the amount of available memory was calculated as

 min(the amount currently in use + headroom according to memcg,
     total clean memory)

This isn't quite correct as what should be capped by the amount of
clean memory is the headroom, not the sum of memory in use and
headroom.  For example, if a memcg domain has a significant amount of
dirty memory, the above can lead to a value which is lower than the
current amount in use which doesn't make much sense.  In most
circumstances, the above leads to a number which is somewhat but not
drastically lower.

As the amount of memory which can be readily allocated to the memcg
domain is capped by the amount of system-wide clean memory which is
not already assigned to the memcg itself, the number we want is

 the amount currently in use +
 min(headroom according to memcg, clean memory elsewhere in the system)

This patch updates mem_cgroup_wb_stats() to return the number of
filepages and headroom instead of the calculated available pages.
mdtc_cap_avail() is renamed to mdtc_calc_avail() and performs the
above calculation from file, headroom, dirty and globally clean pages.

v2: Dummy mem_cgroup_wb_stats() implementation wasn't updated leading
    to build failure when !CGROUP_WRITEBACK.  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: c2aa723a60 ("writeback: implement memcg writeback domain based throttling")
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12 10:31:13 -06:00
Tejun Heo
d60d1bddd5 writeback: memcg dirty_throttle_control should be initialized with wb->memcg_completions
MDTC_INIT() is used to initialize dirty_throttle_control for memcg
domains.  It used DTC_INIT_COMMON() to initialized mdtc->wb and
->wb_completions which is incorrect as DTC_INIT_COMMON() sets the
latter to wb->completions instead of wb->memcg_completions.  This can
lead to wildly incorrect results when calculating the proportion of
dirty memory the memcg domain should get.

Remove DTC_INIT_COMMON() and update MDTC_INIT() to initialize
mdtc->wb_completions to wb->memcg_completions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: c2aa723a60 ("writeback: implement memcg writeback domain based throttling")
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12 10:31:13 -06:00
Tejun Heo
b817525a4a writeback: bdi_writeback iteration must not skip dying ones
bdi_for_each_wb() is used in several places to wake up or issue
writeback work items to all wb's (bdi_writeback's) on a given bdi.
The iteration is performed by walking bdi->cgwb_tree; however, the
tree only indexes wb's which are currently active.

For example, when a memcg gets associated with a different blkcg, the
old wb is removed from the tree so that the new one can be indexed.
The old wb starts dying from then on but will linger till all its
inodes are drained.  As these dying wb's may still host dirty inodes,
writeback operations which affect all wb's must include them.
bdi_for_each_wb() skipping dying wb's led to sync(2) missing and
failing to sync the inodes belonging to those wb's.

This patch adds a RCU protected @bdi->wb_list which lists all wb's
beloinging to that bdi.  wb's are added on creation and removed on
release rather than on the start of destruction.  bdi_for_each_wb()
usages are replaced with list_for_each[_continue]_rcu() iterations
over @bdi->wb_list and bdi_for_each_wb() and its helpers are removed.

v2: Updated as per Jan.  last_wb ref leak in bdi_split_work_to_wbs()
    fixed and unnecessary list head severing in cgwb_bdi_destroy()
    removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Artem Bityutskiy <dedekind1@gmail.com>
Fixes: ebe41ab0c7 ("writeback: implement bdi_for_each_wb()")
Link: http://lkml.kernel.org/g/1443012552.19983.209.camel@gmail.com
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12 10:31:12 -06:00
Tejun Heo
9ad18ab938 writeback: laptop_mode_timer_fn() needs rcu_read_lock() around bdi_writeback iteration
laptop_mode_timer_fn() was using bdi_for_each_wb() without the
required RCU locking leading to the following warning.

 WARNING: CPU: 0 PID: 0 at include/linux/backing-dev.h:415 laptop_mode_timer_fn+0x106/0x170()
 ...
 Call Trace:
  <IRQ>  [<ffffffff81480cdc>] dump_stack+0x4e/0x82
  [<ffffffff81051912>] warn_slowpath_common+0x82/0xc0
  [<ffffffff81051a0a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8115f0e6>] laptop_mode_timer_fn+0x106/0x170
  [<ffffffff810ca8e3>] call_timer_fn+0xb3/0x2f0
  [<ffffffff810cad25>] run_timer_softirq+0x205/0x370
  [<ffffffff81056854>] __do_softirq+0xd4/0x460
  [<ffffffff81056d69>] irq_exit+0x89/0xa0
  [<ffffffff8185a892>] smp_apic_timer_interrupt+0x42/0x50
  [<ffffffff81858a44>] apic_timer_interrupt+0x84/0x90
 ...

Fix it by adding rcu_read_lock() around the iteration.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: a06fd6b102 ("writeback: make laptop_mode_timer_fn() handle multiple bdi_writeback's")
Reviewed-by: Jan Kara <jack@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12 10:31:09 -06:00
Linus Torvalds
b0a1ea51bd Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-block
Pull blk-cg updates from Jens Axboe:
 "A bit later in the cycle, but this has been in the block tree for a a
  while.  This is basically four patchsets from Tejun, that improve our
  buffered cgroup writeback.  It was dependent on the other cgroup
  changes, but they went in earlier in this cycle.

  Series 1 is set of 5 patches that has cgroup writeback updates:

   - bdi_writeback iteration fix which could lead to some wb's being
     skipped or repeated during e.g. sync under memory pressure.

   - Simplification of wb work wait mechanism.

   - Writeback tracepoints updated to report cgroup.

  Series 2 is is a set of updates for the CFQ cgroup writeback handling:

     cfq has always charged all async IOs to the root cgroup.  It didn't
     have much choice as writeback didn't know about cgroups and there
     was no way to tell who to blame for a given writeback IO.
     writeback finally grew support for cgroups and now tags each
     writeback IO with the appropriate cgroup to charge it against.

     This patchset updates cfq so that it follows the blkcg each bio is
     tagged with.  Async cfq_queues are now shared across cfq_group,
     which is per-cgroup, instead of per-request_queue cfq_data.  This
     makes all IOs follow the weight based IO resource distribution
     implemented by cfq.

     - Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff.

     - Other misc review points addressed, acks added and rebased.

  Series 3 is the blkcg policy cleanup patches:

     This patchset contains assorted cleanups for blkcg_policy methods
     and blk[c]g_policy_data handling.

     - alloc/free added for blkg_policy_data.  exit dropped.

     - alloc/free added for blkcg_policy_data.

     - blk-throttle's async percpu allocation is replaced with direct
       allocation.

     - all methods now take blk[c]g_policy_data instead of blkcg_gq or
       blkcg.

  And finally, series 4 is a set of patches cleaning up the blkcg stats
  handling:

    blkcg's stats have always been somwhat of a mess.  This patchset
    tries to improve the situation a bit.

     - The following patches added to consolidate blkcg entry point and
       blkg creation.  This is in itself is an improvement and helps
       colllecting common stats on bio issue.

     - per-blkg stats now accounted on bio issue rather than request
       completion so that bio based and request based drivers can behave
       the same way.  The issue was spotted by Vivek.

     - cfq-iosched implements custom recursive stats and blk-throttle
       implements custom per-cpu stats.  This patchset make blkcg core
       support both by default.

     - cfq-iosched and blk-throttle keep track of the same stats
       multiple times.  Unify them"

* 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits)
  blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
  blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/
  blkcg: implement interface for the unified hierarchy
  blkcg: misc preparations for unified hierarchy interface
  blkcg: separate out tg_conf_updated() from tg_set_conf()
  blkcg: move body parsing from blkg_conf_prep() to its callers
  blkcg: mark existing cftypes as legacy
  blkcg: rename subsystem name from blkio to io
  blkcg: refine error codes returned during blkcg configuration
  blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device()
  blkcg: reduce stack usage of blkg_rwstat_recursive_sum()
  blkcg: remove cfqg_stats->sectors
  blkcg: move io_service_bytes and io_serviced stats into blkcg_gq
  blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq
  blkcg: make blkcg_[rw]stat per-cpu
  blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it
  blkcg: consolidate blkg creation in blkcg_bio_issue_check()
  blk-throttle: improve queue bypass handling
  blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup()
  blkcg: inline [__]blkg_lookup()
  ...
2015-09-10 18:56:14 -07:00
Tejun Heo
5634cc2aa9 writeback: update writeback tracepoints to report cgroup
The following tracepoints are updated to report the cgroup used during
cgroup writeback.

* writeback_write_inode[_start]
* writeback_queue
* writeback_exec
* writeback_start
* writeback_written
* writeback_wait
* writeback_nowork
* writeback_wake_background
* wbc_writepage
* writeback_queue_io
* bdi_dirty_ratelimit
* balance_dirty_pages
* writeback_sb_inodes_requeue
* writeback_single_inode[_start]

Note that writeback_bdi_register is separated out from writeback_class
as reporting cgroup doesn't make sense to it.  Tracepoints which take
bdi are updated to take bdi_writeback instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-18 15:49:15 -07:00
Rabin Vincent
a50fcb512d writeback: fix initial dirty limit
The initial value of global_wb_domain.dirty_limit set by
writeback_set_ratelimit() is zeroed out by the memset in
wb_domain_init().

Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:42 +03:00
Linus Torvalds
e4bc13adfd Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe:
 "This is the big pull request for adding cgroup writeback support.

  This code has been in development for a long time, and it has been
  simmering in for-next for a good chunk of this cycle too.  This is one
  of those problems that has been talked about for at least half a
  decade, finally there's a solution and code to go with it.

  Also see last weeks writeup on LWN:

        http://lwn.net/Articles/648292/"

* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
  writeback, blkio: add documentation for cgroup writeback support
  vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
  writeback: do foreign inode detection iff cgroup writeback is enabled
  v9fs: fix error handling in v9fs_session_init()
  bdi: fix wrong error return value in cgwb_create()
  buffer: remove unusued 'ret' variable
  writeback: disassociate inodes from dying bdi_writebacks
  writeback: implement foreign cgroup inode bdi_writeback switching
  writeback: add lockdep annotation to inode_to_wb()
  writeback: use unlocked_inode_to_wb transaction in inode_congested()
  writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
  writeback: implement [locked_]inode_to_wb_and_lock_list()
  writeback: implement foreign cgroup inode detection
  writeback: make writeback_control track the inode being written back
  writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
  mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
  writeback: implement memcg writeback domain based throttling
  writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
  writeback: implement memcg wb_domain
  writeback: update wb_over_bg_thresh() to use wb_domain aware operations
  ...
2015-06-25 16:00:17 -07:00
Tejun Heo
682aa8e1a6 writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
The mechanism for detecting whether an inode should switch its wb
(bdi_writeback) association is now in place.  This patch build the
framework for the actual switching.

This patch adds a new inode flag I_WB_SWITCHING, which has two
functions.  First, the easy one, it ensures that there's only one
switching in progress for a give inode.  Second, it's used as a
mechanism to synchronize wb stat updates.

The two stats, WB_RECLAIMABLE and WB_WRITEBACK, aren't event counters
but track the current number of dirty pages and pages under writeback
respectively.  As such, when an inode is moved from one wb to another,
the inode's portion of those stats have to be transferred together;
unfortunately, this is a bit tricky as those stat updates are percpu
operations which are performed without holding any lock in some
places.

This patch solves the problem in a similar way as memcg.  Each such
lockless stat updates are wrapped in transaction surrounded by
unlocked_inode_to_wb_begin/end().  During normal operation, they map
to rcu_read_lock/unlock(); however, if I_WB_SWITCHING is asserted,
mapping->tree_lock is grabbed across the transaction.

In turn, the switching path sets I_WB_SWITCHING and waits for a RCU
grace period to pass before actually starting to switch, which
guarantees that all stat update paths are synchronizing against
mapping->tree_lock.

This patch still doesn't implement the actual switching.

v3: Updated on top of the recent cancel_dirty_page() updates.
    unlocked_inode_to_wb_begin() now nests inside
    mem_cgroup_begin_page_stat() to match the locking order.

v2: The i_wb access transaction will be used for !stat accesses too.
    Function names and comments updated accordingly.

    s/inode_wb_stat_unlocked_{begin|end}/unlocked_inode_to_wb_{begin|end}/
    s/switch_wb/switch_wbs/

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:40:20 -06:00
Tejun Heo
c2aa723a60 writeback: implement memcg writeback domain based throttling
While cgroup writeback support now connects memcg and blkcg so that
writeback IOs are properly attributed and controlled, the IO back
pressure propagation mechanism implemented in balance_dirty_pages()
and its subroutines wasn't aware of cgroup writeback.

Processes belonging to a memcg may have access to only subset of total
memory available in the system and not factoring this into dirty
throttling rendered it completely ineffective for processes under
memcg limits and memcg ended up building a separate ad-hoc degenerate
mechanism directly into vmscan code to limit page dirtying.

The previous patches updated balance_dirty_pages() and its subroutines
so that they can deal with multiple wb_domain's (writeback domains)
and defined per-memcg wb_domain.  Processes belonging to a non-root
memcg are bound to two wb_domains, global wb_domain and memcg
wb_domain, and should be throttled according to IO pressures from both
domains.  This patch updates dirty throttling code so that it repeats
similar calculations for the two domains - the differences between the
two are few and minor - and applies the lower of the two sets of
resulting constraints.

wb_over_bg_thresh(), which controls when background writeback
terminates, is also updated to consider both global and memcg
wb_domains.  It returns true if dirty is over bg_thresh for either
domain.

This makes the dirty throttling mechanism operational for memcg
domains including writeback-bandwidth-proportional dirty page
distribution inside them but the ad-hoc memcg throttling mechanism in
vmscan is still in place.  The next patch will rip it out.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
841710aa6e writeback: implement memcg wb_domain
Dirtyable memory is distributed to a wb (bdi_writeback) according to
the relative bandwidth the wb is writing out in the whole system.
This distribution is global - each wb is measured against all other
wb's and gets the proportinately sized portion of the memory in the
whole system.

For cgroup writeback, the amount of dirtyable memory is scoped by
memcg and thus each wb would need to be measured and controlled in its
memcg.  IOW, a wb will belong to two writeback domains - the global
and memcg domains.

The previous patches laid the groundwork to support the two wb_domains
and this patch implements memcg wb_domain.  memcg->cgwb_domain is
initialized on css online and destroyed on css release,
wb->memcg_completions is added, and __wb_writeout_inc() is updated to
increment completions against both global and memcg wb_domains.

The following patches will update balance_dirty_pages() and its
subroutines to actually consider memcg wb_domain for throttling.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
947e9762a8 writeback: update wb_over_bg_thresh() to use wb_domain aware operations
wb_over_bg_thresh() currently uses global_dirty_limits() and
wb_dirty_limit() both of which are wrappers around operations which
take dirty_throttle_control.  For cgroup writeback support, the
function will be updated to also consider memcg wb_domains which
requires the context information carried in dirty_throttle_control.

This patch updates wb_over_bg_thresh() so that it uses the underlying
wb_domain aware operations directly and builds the global
dirty_throttle_control in the process.

This patch doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
aa661bbe1e writeback: move over_bground_thresh() to mm/page-writeback.c
and rename it to wb_over_bg_thresh().  The function is closely tied to
the dirty throttling mechanism implemented in page-writeback.c.  This
relocation will allow future updates necessary for cgroup writeback
support.

While at it, add function comment.

This is pure reorganization and doesn't introduce any behavioral
changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
9fc3a43e17 writeback: separate out domain_dirty_limits()
global_dirty_limits() calculates thresh and bg_thresh (confusingly
called *pdirty and *pbackground in the function) assuming
global_wb_domain; however, cgroup writeback support requires
considering per-memcg wb_domain too.

This patch separates out domain_dirty_limits() which takes
dirty_throttle_control out of global_dirty_limits().  As thresh and
bg_thresh calculation needs the amount of dirtyable memory in the
domain, dirty_throttle_control->avail is added.  The new function
calculates the two thresholds and store them directly in the
dirty_throttle_control.

Also, as memcg domains can't follow vm_dirty_bytes and
dirty_background_bytes settings directly.  If those are set and
domain_dirty_limits() is invoked for a !global domain, the settings
are translated to ratios by scaling them against globally available
memory.  dirty_throttle_control->gdtc is added to enable this when
CONFIG_CGROUP_WRITEBACK.

global_dirty_limits() is now a thin wrapper around
domain_dirty_limits() and balance_dirty_pages() is updated to use the
new function too.

This patch doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
c7981433ef writeback: make __wb_writeout_inc() and hard_dirty_limit() take wb_domaas a parameter
Currently __wb_writeout_inc() and hard_dirty_limit() assume
global_wb_domain; however, cgroup writeback support requires
considering per-memcg wb_domain too.

This patch separates out domain-specific part of __wb_writeout_inc()
into wb_domain_writeout_inc() which takes wb_domain as a parameter and
adds the parameter to hard_dirty_limit().  This will allow these two
functions to handle per-memcg wb_domains.

This patch doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
e9f07dfd70 writeback: add dirty_throttle_control->dom
Currently all dirty throttle operations use global_wb_domain; however,
cgroup writeback support requires considering per-memcg wb_domain too.
This patch adds dirty_throttle_control->dom and updates functions
which are directly using globabl_wb_domain to use it instead.

As this makes global_update_bandwidth() a misnomer, the function is
renamed to domain_update_bandwidth().

This patch doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
e9770b3487 writeback: add dirty_throttle_control->wb_completions
wb->completions measures the wb's proportional write bandwidth in
global_wb_domain and thus naturally tied to the wb_domain.  This patch
adds dirty_throttle_control->wb_completions which is initialized to
wb->completions by GDTC_INIT() and updates __wb_dirty_limits() to use
it instead of dereferencing wb->completions directly.

This will allow dirty_throttle_control to represent different
wb_domains and the matching wb completions.

This patch doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
daddfa3cb3 writeback: add dirty_throttle_control->pos_ratio
wb_position_ratio() is used to calculate pos_ratio, which is used for
two purposes.  wb_update_dirty_ratelimit() uses it to adjust
wb->[balanced_]dirty_ratelimit gradually and balance_dirty_pages() to
immediately adjust dirty_ratelimit right before applying it to
determine pause duration.

While wb_update_dirty_ratelimit() is separately rate limited from
balance_dirty_pages(), on the run where the ratelimit is updated, we
end up calculating pos_ratio twice with the same parameters.

This patch adds dirty_throttle_control->pos_ratio.
balance_dirty_pages() calculates it once per run and
wb_update_dirty_ratelimit() uses the value stored in
dirty_throttle_control.

This removes the duplicate calculation and also will help implementing
memcg wb_domain.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
b1cbc6d40c writeback: make __wb_calc_thresh() take dirty_throttle_control
wb_calc_thresh() calculates wb_thresh by scaling thresh according to
the wb's portion in the system-wide write bandwidth.  cgroup writeback
support would need to calculate wb_thresh against memcg domain too.
This patch renames wb_calc_thresh() to __wb_calc_thresh() and makes it
take dirty_throttle_control so that the function can later be updated
to calculate against different domains according to
dirty_throttle_control.

wb_calc_thresh() is now a thin wrapper around __wb_calc_thresh().

v2: The original version was incorrectly scaling dtc->dirty instead of
    dtc->thresh.  This was due to the extremely confusing function and
    variable names.  Added a rename patch and fixed this one.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
970fb01ad3 writeback: add dirty_throttle_control->wb_bg_thresh
wb_bg_thresh is currently treated as a second-class citizen.  It's
only used when BDI_CAP_STRICTLIMIT is set and balance_dirty_pages()
doesn't calculate it unless the cap is set.  When the cap is set, the
calculated value is not passed around but instead recalculated
whenever it's used.

wb_position_ratio() calculates it by scaling wb_thresh proportional to
bg_thresh / thresh.  wb_update_dirty_ratelimit() uses wb_dirty_limit()
on bg_thresh, which should generally lead to a similar result as the
proportional scaling but can also be way off in the presence of
max/min_ratio settings.

Avoiding wb_bg_thresh calculation saves us one u64 multiplication and
divsion when BDI_CAP_STRICTLIMIT is not set.  Given that
balance_dirty_pages() is already ratelimited, this doesn't justify the
incurred extra complexity.

This patch adds wb_bg_thresh to dirty_throttle_control and makes
wb_dirty_limits() always calculate it and updates the users to use the
pre-calculated value.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
2bc00aef03 writeback: consolidate dirty throttle parameters into dirty_throttle_control
Dirty throttling implemented in balance_dirty_pages() and its
subroutines makes use of a number of parameters which are passed
around individually.  This renders these functions somewhat unwieldy
and makes it difficult to add or change the involved parameters.  Also
some functions use different or conflicting naming schemes for the
same parameters making the code confusing to follow.

This patch consolidates the main parameters into struct
dirty_throttle_control so that they can be passed around easily and
adding new paramters isn't painful.  This also unifies how a given
parameter is named and accessed.  The drawback of using this type of
control structure rather than explicit paramters is that it isn't
immediately obvious which function accesses and modifies what;
however, it's fairly clear that the benefits outweigh in this case.

GDTC_INIT() macro is provided to ease initializing
dirty_throttle_control for the global_wb_domain and
balance_dirty_pages() uses a separate pointer to point to its global
dirty_throttle_control.  This is to make it uniform with memcg domain
handling which will be added later.

This patch doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:12 -06:00
Tejun Heo
dcc25ae76e writeback: move global_dirty_limit into wb_domain
This patch is a part of the series to define wb_domain which
represents a domain that wb's (bdi_writeback's) belong to and are
measured against each other in.  This will enable IO backpressure
propagation for cgroup writeback.

global_dirty_limit exists to regulate the global dirty threshold which
is a property of the wb_domain.  This patch moves hard_dirty_limit,
dirty_lock, and update_time into wb_domain.

This is pure reorganization and doesn't introduce any behavioral
changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:12 -06:00
Tejun Heo
380c27ca33 writeback: implement wb_domain
Dirtyable memory is distributed to a wb (bdi_writeback) according to
the relative bandwidth the wb is writing out in the whole system.
This distribution is global - each wb is measured against all other
wb's and gets the proportinately sized portion of the memory in the
whole system.

For cgroup writeback, the amount of dirtyable memory is scoped by
memcg and thus each wb would need to be measured and controlled in its
memcg.  IOW, a wb will belong to two writeback domains - the global
and memcg domains.

Currently, what constitutes the global writeback domain are scattered
across a number of global states.  This patch starts collecting them
into struct wb_domain.

* fprop_global which serves as the basis for proportional bandwidth
  measurement and its period timer are moved into struct wb_domain.

* global_wb_domain hosts the states for the global domain.

* While at it, flatten wb_writeout_fraction() into its callers.  This
  thin wrapper doesn't provide any actual benefits while getting in
  the way.

This is pure reorganization and doesn't introduce any behavioral
changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:12 -06:00
Tejun Heo
8a73179956 writeback: reorganize [__]wb_update_bandwidth()
__wb_update_bandwidth() is called from two places -
fs/fs-writeback.c::balance_dirty_pages() and
mm/page-writeback.c::wb_writeback().  The latter updates only the
write bandwidth while the former also deals with the dirty ratelimit.
The two callsites are distinguished by whether @thresh parameter is
zero or not, which is cryptic.  In addition, the two files define
their own different versions of wb_update_bandwidth() on top of
__wb_update_bandwidth(), which is confusing to say the least.  This
patch cleans up [__]wb_update_bandwidth() in the following ways.

* __wb_update_bandwidth() now takes explicit @update_ratelimit
  parameter to gate dirty ratelimit handling.

* mm/page-writeback.c::wb_update_bandwidth() is flattened into its
  caller - balance_dirty_pages().

* fs/fs-writeback.c::wb_update_bandwidth() is moved to
  mm/page-writeback.c and __wb_update_bandwidth() is made static.

* While at it, add a lockdep assertion to __wb_update_bandwidth().

Except for the lockdep addition, this is pure reorganization and
doesn't introduce any behavioral changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:12 -06:00
Tejun Heo
0d960a383a writeback: clean up wb_dirty_limit()
The function name wb_dirty_limit(), its argument @dirty and the local
variable @wb_dirty are mortally confusing given that the function
calculates per-wb threshold value not dirty pages, especially given
that @dirty and @wb_dirty are used elsewhere for dirty pages.

Let's rename the function to wb_calc_thresh() and wb_dirty to
wb_thresh.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:12 -06:00
Tejun Heo
9ecf4866c0 writeback: make bdi_start_background_writeback() take bdi_writeback instead of backing_dev_info
bdi_start_background_writeback() currently takes @bdi and kicks the
root wb (bdi_writeback).  In preparation for cgroup writeback support,
make it take wb instead.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:36 -06:00
Tejun Heo
bc05873dcc writeback: make writeback_in_progress() take bdi_writeback instead of backing_dev_info
writeback_in_progress() currently takes @bdi and returns whether
writeback is in progress on its root wb (bdi_writeback).  In
preparation for cgroup writeback support, make it take wb instead.
While at it, make it an inline function.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:36 -06:00
Tejun Heo
a06fd6b102 writeback: make laptop_mode_timer_fn() handle multiple bdi_writeback's
For cgroup writeback support, all bdi-wide operations should be
distributed to all its wb's (bdi_writeback's).

This patch updates laptop_mode_timer_fn() so that it invokes
wb_start_writeback() on all wb's rather than just the root one.  As
the intent is writing out all dirty data, there's no reason to split
the number of pages to write.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:36 -06:00
Tejun Heo
c00ddad39f writeback: remove bdi_start_writeback()
bdi_start_writeback() is a thin wrapper on top of
__wb_start_writeback() which is used only by laptop_mode_timer_fn().
This patches removes bdi_start_writeback(), renames
__wb_start_writeback() to wb_start_writeback() and makes
laptop_mode_timer_fn() use it instead.

This doesn't cause any functional difference and will ease making
laptop_mode_timer_fn() cgroup writeback aware.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:36 -06:00
Tejun Heo
693108a8a6 writeback: make bdi->min/max_ratio handling cgroup writeback aware
bdi->min/max_ratio are user-configurable per-bdi knobs which regulate
dirty limit of each bdi.  For cgroup writeback, they need to be
further distributed across wb's (bdi_writeback's) belonging to the
configured bdi.

This patch introduces wb_min_max_ratio() which distributes
bdi->min/max_ratio according to a wb's proportion in the total active
bandwidth of its bdi.

v2: Update wb_min_max_ratio() to fix a bug where both min and max were
    assigned the min value and avoid calculations when possible.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:36 -06:00
Tejun Heo
95a46c65e3 writeback: make bdi_has_dirty_io() take multiple bdi_writeback's into account
bdi_has_dirty_io() used to only reflect whether the root wb
(bdi_writeback) has dirty inodes.  For cgroup writeback support, it
needs to take all active wb's into account.  If any wb on the bdi has
dirty inodes, bdi_has_dirty_io() should return true.

To achieve that, as inode_wb_list_{move|del}_locked() now keep track
of the dirty state transition of each wb, the number of dirty wbs can
be counted in the bdi; however, bdi is already aggregating
wb->avg_write_bandwidth which can easily be guaranteed to be > 0 when
there are any dirty inodes by ensuring wb->avg_write_bandwidth can't
dip below 1.  bdi_has_dirty_io() can simply test whether
bdi->tot_write_bandwidth is zero or not.

While this bumps the value of wb->avg_write_bandwidth to one when it
used to be zero, this shouldn't cause any meaningful behavior
difference.

bdi_has_dirty_io() is made an inline function which tests whether
->tot_write_bandwidth is non-zero.  Also, WARN_ON_ONCE()'s on its
value are added to inode_wb_list_{move|del}_locked().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:36 -06:00
Tejun Heo
766a9d6e60 writeback: implement backing_dev_info->tot_write_bandwidth
cgroup writeback support needs to keep track of the sum of
avg_write_bandwidth of all wb's (bdi_writeback's) with dirty inodes to
distribute write workload.  This patch adds bdi->tot_write_bandwidth
and updates inode_wb_list_move_locked(), inode_wb_list_del_locked()
and wb_update_write_bandwidth() to adjust it as wb's gain and lose
dirty inodes and its avg_write_bandwidth gets updated.

As the update events are not synchronized with each other,
bdi->tot_write_bandwidth is an atomic_long_t.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo
dfb8ae5678 writeback: let balance_dirty_pages() work on the matching cgroup bdi_writeback
Currently, balance_dirty_pages() always work on bdi->wb.  This patch
updates it to work on the wb (bdi_writeback) matching memcg and blkcg
of the current task as that's what the inode is being dirtied against.

balance_dirty_pages_ratelimited() now pins the current wb and passes
it to balance_dirty_pages().

As no filesystem has FS_CGROUP_WRITEBACK yet, this doesn't lead to
visible behavior differences.

v2: Updated for per-inode wb association.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo
9101813437 writeback: attribute stats to the matching per-cgroup bdi_writeback
Until now, all WB_* stats were accounted against the root wb
(bdi_writeback), now that multiple wb (bdi_writeback) support is in
place, let's attributes the stats to the respective per-cgroup wb's.

As no filesystem has FS_CGROUP_WRITEBACK yet, this doesn't lead to
visible behavior differences.

v2: Updated for per-inode wb association.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo
52ebea749a writeback: make backing_dev_info host cgroup-specific bdi_writebacks
For the planned cgroup writeback support, on each bdi
(backing_dev_info), each memcg will be served by a separate wb
(bdi_writeback).  This patch updates bdi so that a bdi can host
multiple wbs (bdi_writebacks).

On the default hierarchy, blkcg implicitly enables memcg.  This allows
using memcg's page ownership for attributing writeback IOs, and every
memcg - blkcg combination can be served by its own wb by assigning a
dedicated wb to each memcg.  This means that there may be multiple
wb's of a bdi mapped to the same blkcg.  As congested state is per
blkcg - bdi combination, those wb's should share the same congested
state.  This is achieved by tracking congested state via
bdi_writeback_congested structs which are keyed by blkcg.

bdi->wb remains unchanged and will keep serving the root cgroup.
cgwb's (cgroup wb's) for non-root cgroups are created on-demand or
looked up while dirtying an inode according to the memcg of the page
being dirtied or current task.  Each cgwb is indexed on bdi->cgwb_tree
by its memcg id.  Once an inode is associated with its wb, it can be
retrieved using inode_to_wb().

Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all
pages will keep being associated with bdi->wb.

v3: inode_attach_wb() in account_page_dirtied() moved inside
    mapping_cap_account_dirty() block where it's known to be !NULL.
    Also, an unnecessary NULL check before kfree() removed.  Both
    detected by the kbuild bot.

v2: Updated so that wb association is per inode and wb is per memcg
    rather than blkcg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo
de1fff37b2 writeback: s/bdi/wb/ in mm/page-writeback.c
Writeback operations will now be per wb (bdi_writeback) instead of
bdi.  Replace the relevant bdi references in symbol names and comments
with wb.  This patch is purely cosmetic and doesn't make any
functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo
a88a341a73 writeback: move bandwidth related fields from backing_dev_info into bdi_writeback
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear.  For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi.  To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.

This patch moves bandwidth related fields from backing_dev_info into
bdi_writeback.

* The moved fields are: bw_time_stamp, dirtied_stamp, written_stamp,
  write_bandwidth, avg_write_bandwidth, dirty_ratelimit,
  balanced_dirty_ratelimit, completions and dirty_exceeded.

* writeback_chunk_size() and over_bground_thresh() now take @wb
  instead of @bdi.

* bdi_writeout_fraction(bdi, ...)	-> wb_writeout_fraction(wb, ...)
  bdi_dirty_limit(bdi, ...)		-> wb_dirty_limit(wb, ...)
  bdi_position_ration(bdi, ...)		-> wb_position_ratio(wb, ...)
  bdi_update_writebandwidth(bdi, ...)	-> wb_update_write_bandwidth(wb, ...)
  [__]bdi_update_bandwidth(bdi, ...)	-> [__]wb_update_bandwidth(wb, ...)
  bdi_{max|min}_pause(bdi, ...)		-> wb_{max|min}_pause(wb, ...)
  bdi_dirty_limits(bdi, ...)		-> wb_dirty_limits(wb, ...)

* Init/exits of the relocated fields are moved to bdi_wb_init/exit()
  respectively.  Note that explicit zeroing is dropped in the process
  as wb's are cleared in entirety anyway.

* As there's still only one bdi_writeback per backing_dev_info, all
  uses of bdi->stat[] are mechanically replaced with bdi->wb.stat[]
  introducing no behavior changes.

v2: Typo in description fixed as suggested by Jan.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo
93f78d8828 writeback: move backing_dev_info->bdi_stat[] into bdi_writeback
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear.  For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi.  To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.

This patch moves bdi->bdi_stat[] into wb.

* enum bdi_stat_item is renamed to wb_stat_item and the prefix of all
  enums is changed from BDI_ to WB_.

* BDI_STAT_BATCH() -> WB_STAT_BATCH()

* [__]{add|inc|dec|sum}_wb_stat(bdi, ...) -> [__]{add|inc}_wb_stat(wb, ...)

* bdi_stat[_error]() -> wb_stat[_error]()

* bdi_writeout_inc() -> wb_writeout_inc()

* stat init is moved to bdi_wb_init() and bdi_wb_exit() is added and
  frees stat.

* As there's still only one bdi_writeback per backing_dev_info, all
  uses of bdi->stat[] are mechanically replaced with bdi->wb.stat[]
  introducing no behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Greg Thelen
c4843a7593 memcg: add per cgroup dirty page accounting
When modifying PG_Dirty on cached file pages, update the new
MEM_CGROUP_STAT_DIRTY counter.  This is done in the same places where
global NR_FILE_DIRTY is managed.  The new memcg stat is visible in the
per memcg memory.stat cgroupfs file.  The most recent past attempt at
this was http://thread.gmane.org/gmane.linux.kernel.cgroups/8632

The new accounting supports future efforts to add per cgroup dirty
page throttling and writeback.  It also helps an administrator break
down a container's memory usage and provides evidence to understand
memcg oom kills (the new dirty count is included in memcg oom kill
messages).

The ability to move page accounting between memcg
(memory.move_charge_at_immigrate) makes this accounting more
complicated than the global counter.  The existing
mem_cgroup_{begin,end}_page_stat() lock is used to serialize move
accounting with stat updates.
Typical update operation:
	memcg = mem_cgroup_begin_page_stat(page)
	if (TestSetPageDirty()) {
		[...]
		mem_cgroup_update_page_stat(memcg)
	}
	mem_cgroup_end_page_stat(memcg)

Summary of mem_cgroup_end_page_stat() overhead:
- Without CONFIG_MEMCG it's a no-op
- With CONFIG_MEMCG and no inter memcg task movement, it's just
  rcu_read_lock()
- With CONFIG_MEMCG and inter memcg  task movement, it's
  rcu_read_lock() + spin_lock_irqsave()

A memcg parameter is added to several routines because their callers
now grab mem_cgroup_begin_page_stat() which returns the memcg later
needed by for mem_cgroup_update_page_stat().

Because mem_cgroup_begin_page_stat() may disable interrupts, some
adjustments are needed:
- move __mark_inode_dirty() from __set_page_dirty() to its caller.
  __mark_inode_dirty() locking does not want interrupts disabled.
- use spin_lock_irqsave(tree_lock) rather than spin_lock_irq() in
  __delete_from_page_cache(), replace_page_cache_page(),
  invalidate_complete_page2(), and __remove_mapping().

   text    data     bss      dec    hex filename
8925147 1774832 1785856 12485835 be84cb vmlinux-!CONFIG_MEMCG-before
8925339 1774832 1785856 12486027 be858b vmlinux-!CONFIG_MEMCG-after
                            +192 text bytes
8965977 1784992 1785856 12536825 bf4bf9 vmlinux-CONFIG_MEMCG-before
8966750 1784992 1785856 12537598 bf4efe vmlinux-CONFIG_MEMCG-after
                            +773 text bytes

Performance tests run on v4.0-rc1-36-g4f671fe2f952.  Lower is better for
all metrics, they're all wall clock or cycle counts.  The read and write
fault benchmarks just measure fault time, they do not include I/O time.

* CONFIG_MEMCG not set:
                            baseline                              patched
  kbuild                 1m25.030000(+-0.088% 3 samples)       1m25.426667(+-0.120% 3 samples)
  dd write 100 MiB          0.859211561 +-15.10%                  0.874162885 +-15.03%
  dd write 200 MiB          1.670653105 +-17.87%                  1.669384764 +-11.99%
  dd write 1000 MiB         8.434691190 +-14.15%                  8.474733215 +-14.77%
  read fault cycles       254.0(+-0.000% 10 samples)            253.0(+-0.000% 10 samples)
  write fault cycles     2021.2(+-3.070% 10 samples)           1984.5(+-1.036% 10 samples)

* CONFIG_MEMCG=y root_memcg:
                            baseline                              patched
  kbuild                 1m25.716667(+-0.105% 3 samples)       1m25.686667(+-0.153% 3 samples)
  dd write 100 MiB          0.855650830 +-14.90%                  0.887557919 +-14.90%
  dd write 200 MiB          1.688322953 +-12.72%                  1.667682724 +-13.33%
  dd write 1000 MiB         8.418601605 +-14.30%                  8.673532299 +-15.00%
  read fault cycles       266.0(+-0.000% 10 samples)            266.0(+-0.000% 10 samples)
  write fault cycles     2051.7(+-1.349% 10 samples)           2049.6(+-1.686% 10 samples)

* CONFIG_MEMCG=y non-root_memcg:
                            baseline                              patched
  kbuild                 1m26.120000(+-0.273% 3 samples)       1m25.763333(+-0.127% 3 samples)
  dd write 100 MiB          0.861723964 +-15.25%                  0.818129350 +-14.82%
  dd write 200 MiB          1.669887569 +-13.30%                  1.698645885 +-13.27%
  dd write 1000 MiB         8.383191730 +-14.65%                  8.351742280 +-14.52%
  read fault cycles       265.7(+-0.172% 10 samples)            267.0(+-0.000% 10 samples)
  write fault cycles     2070.6(+-1.512% 10 samples)           2084.4(+-2.148% 10 samples)

As expected anon page faults are not affected by this patch.

tj: Updated to apply on top of the recent cancel_dirty_page() changes.

Signed-off-by: Sha Zhengju <handai.szj@gmail.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:33 -06:00
Tejun Heo
11f81becca page_writeback: revive cancel_dirty_page() in a restricted form
cancel_dirty_page() had some issues and b9ea25152e ("page_writeback:
clean up mess around cancel_dirty_page()") replaced it with
account_page_cleaned() which makes the caller responsible for clearing
the dirty bit; unfortunately, the planned changes for cgroup writeback
support requires synchronization between dirty bit manipulation and
stat updates.  While we can open-code such synchronization in each
account_page_cleaned() callsite, that's gonna be unnecessarily awkward
and verbose.

This patch revives cancel_dirty_page() but in a more restricted form.
All it does is TestClearPageDirty() followed by account_page_cleaned()
invocation if the page was dirty.  This helper covers all
account_page_cleaned() usages except for __delete_from_page_cache()
which is a special case anyway and left alone.  As this leaves no
module user for account_page_cleaned(), EXPORT_SYMBOL() is dropped
from it.

This patch just revives cancel_dirty_page() as a trivial wrapper to
replace equivalent usages and doesn't introduce any functional
changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:33 -06:00
Tejun Heo
464d1387ac writeback: use |1 instead of +1 to protect against div by zero
mm/page-writeback.c has several places where 1 is added to the divisor
to prevent division by zero exceptions; however, if the original
divisor is equivalent to -1, adding 1 leads to division by zero.

There are three places where +1 is used for this purpose - one in
pos_ratio_polynom() and two in bdi_position_ratio().  The second one
in bdi_position_ratio() actually triggered div-by-zero oops on a
machine running a 3.10 kernel.  The divisor is

  x_intercept - bdi_setpoint + 1 == span + 1

span is confirmed to be (u32)-1.  It isn't clear how it ended up that
but it could be from write bandwidth calculation underflow fixed by
c72efb658f ("writeback: fix possible underflow in write bandwidth
calculation").

At any rate, +1 isn't a proper protection against div-by-zero.  This
patch converts all +1 protections to |1.  Note that
bdi_update_dirty_ratelimit() was already using |1 before this patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-23 10:36:33 -06:00
Naoya Horiguchi
a4bb3ecdc1 mm/page-writeback: check-before-clear PageReclaim
With the page flag sanitization patchset, an invalid usage of
ClearPageReclaim() is detected in set_page_dirty().  This can be called
from __unmap_hugepage_range(), so let's check PageReclaim() before trying
to clear it to avoid the misuse.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:17 -07:00
Konstantin Khlebnikov
b9ea25152e page_writeback: clean up mess around cancel_dirty_page()
This patch replaces cancel_dirty_page() with a helper function
account_page_cleaned() which only updates counters.  It's called from
truncate_complete_page() and from try_to_free_buffers() (hack for ext3).
Page is locked in both cases, page-lock protects against concurrent
dirtiers: see commit 2d6d7f9828 ("mm: protect set_page_dirty() from
ongoing truncation").

Delete_from_page_cache() shouldn't be called for dirty pages, they must
be handled by caller (either written or truncated).  This patch treats
final dirty accounting fixup at the end of __delete_from_page_cache() as
a debug check and adds WARN_ON_ONCE() around it.  If something removes
dirty pages without proper handling that might be a bug and unwritten
data might be lost.

Hugetlbfs has no dirty pages accounting, ClearPageDirty() is enough
here.

cancel_dirty_page() in nfs_wb_page_cancel() is redundant.  This is
helper for nfs_invalidate_page() and it's called only in case complete
invalidation.

The mess was started in v2.6.20 after commits 46d2277c79 ("Clean up
and make try_to_free_buffers() not race with dirty pages") and
3e67c0987d ("truncate: clear page dirtiness before running
try_to_free_buffers()") first was reverted right in v2.6.20 in commit
ecdfc9787f ("Resurrect 'try_to_free_buffers()' VM hackery"), second in
v2.6.25 commit a2b345642f ("Fix dirty page accounting leak with ext3
data=journal").

Custom fixes were introduced between these points.  NFS in v2.6.23, commit
1b3b4a1a2d ("NFS: Fix a write request leak in nfs_invalidate_page()").
Kludge in __delete_from_page_cache() in v2.6.24, commit 3a6927906f ("Do
dirty page accounting when removing a page from the page cache").  Since
v2.6.25 all of them are redundant.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:01 -07:00
Tejun Heo
c72efb658f writeback: fix possible underflow in write bandwidth calculation
From 1ebf33901ecc75d9496862dceb1ef0377980587c Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Mon, 23 Mar 2015 00:08:19 -0400

2f800fbd77 ("writeback: fix dirtied pages accounting on redirty")
introduced account_page_redirty() which reverts stat updates for a
redirtied page, making BDI_DIRTIED no longer monotonically increasing.

bdi_update_write_bandwidth() uses the delta in BDI_DIRTIED as the
basis for bandwidth calculation.  While unlikely, since the above
patch, the newer value may be lower than the recorded past value and
underflow the bandwidth calculation leading to a wild result.

Fix it by subtracing min of the old and new values when calculating
delta.  AFAIK, there hasn't been any report of it happening but the
resulting erratic behavior would be non-critical and temporary, so
it's possible that the issue is happening without being reported.  The
risk of the fix is very low, so tagged for -stable.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Fixes: 2f800fbd77 ("writeback: fix dirtied pages accounting on redirty")
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-23 09:35:58 -06:00