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693 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
Minchan Kim
06de050ac6 mm: Enhance per process reclaim to consider shared pages
Some pages could be shared by several processes. (ex, libc)
In case of that, it's too bad to reclaim them from the beginnig.

This patch causes VM to keep them on memory until last task
try to reclaim them so shared pages will be reclaimed only if
all of task has gone swapping out.

This feature doesn't handle non-linear mapping on ramfs because
it's very time-consuming and doesn't make sure of reclaiming and
not common.

Change-Id: I7e5f34f2e947f5db6d405867fe2ad34863ca40f7
Signed-off-by: Sangseok Lee <sangseok.lee@lge.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Patch-mainline: linux-mm @ 9 May 2013 16:21:27
[vinmenon@codeaurora.org: trivial merge conflict fixes + changes
to make the patch work with 3.18 kernel]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-06-22 14:43:57 -07:00
Minchan Kim
a4e92011d4 mm: Remove shrink_page
By previous patch, shrink_page_list can handle pages from
multiple zone so let's remove shrink_page.

Change-Id: I3526377aa6ee6142b8f3ec63396e7ada1e442505
Signed-off-by: Minchan Kim <minchan@kernel.org>
Patch-mainline: linux-mm @ 22 Apr 2013 17:45:03
[vinmenon@codeaurora.org: trivial merge conflict fixes]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-06-22 14:43:32 -07:00
Minchan Kim
7d65fdc5d7 mm: make shrink_page_list with pages work from multiple zones
Shrink_page_list expects all pages come from a same zone
but it's too limited to use.

This patch removes the dependency so next patch can use
shrink_page_list with pages from multiple zones.

Change-Id: I34469b7f0a79f2b79e30e40033ba8b3e1dd5f2d0
Signed-off-by: Minchan Kim <minchan@kernel.org>
Patch-mainline: linux-mm @ 9 May 2013 16:21:25
[vinmenon@codeaurora.org: trivial merge conflict fixes]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-06-22 14:43:18 -07:00
Minchan Kim
ecc070a294 mm: Per process reclaim
These day, there are many platforms avaiable in the embedded market
and they are smarter than kernel which has very limited information
about working set so they want to involve memory management more heavily
like android's lowmemory killer and ashmem or recent many lowmemory
notifier.

One of the simple imagine scenario about userspace's intelligence is that
platform can manage tasks as forground and backgroud so it would be
better to reclaim background's task pages for end-user's *responsibility*
although it has frequent referenced pages.

This patch adds new knob "reclaim under proc/<pid>/" so task manager
can reclaim any target process anytime, anywhere. It could give another
method to platform for using memory efficiently.

It can avoid process killing for getting free memory, which was really
terrible experience because I lost my best score of game I had ever
after I switch the phone call while I enjoyed the game.

Reclaim file-backed pages only.
	echo file > /proc/PID/reclaim
Reclaim anonymous pages only.
	echo anon > /proc/PID/reclaim
Reclaim all pages
	echo all > /proc/PID/reclaim

Change-Id: Iabdb7bc2ef3dc4d94e3ea005fbe18f4cd06739ab
Signed-off-by: Minchan Kim <minchan@kernel.org>
Patch-mainline: linux-mm @ 9 May 2013 16:21:24
[vinmenon@codeaurora.org: trivial merge conflict fixes,
and minor tweak of the commit msg]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-06-22 14:43:06 -07:00
Minchan Kim
b3d3ad2c8f mm: prevent to write out dirty page in CMA by may_writepage
Now, local variable references in shrink_page_list is
PAGEREF_RECLAIM_CLEAN as default. It is for preventing to reclaim
dirty pages when CMA try to migrate pages.
Strictly speaking, we don't need it because CMA already didn't allow
to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.

Morever, it has a problem to prevent anonymous pages's swap out when
we use force_reclaim = true in shrink_page_list(ex, per process reclaim
can do it)

So this patch makes references's default value to PAGEREF_RECLAIM
and declare .may_writepage = 0 of scan_control in CMA part to make
code more clear.

Change-Id: I5edc3c955d106ecebc4949ce27daf5b7b7a18089
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mgorman@suse.de>
Reported-by: Minkyung Kim <minkyung88@lge.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Patch-mainline: linux-mm @ 9 May 2013 16:21:23
[vinmenon@codeaurora.org: trivial merge conflict fixes]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-06-22 14:42:54 -07:00
Bob Liu
5248c3b4e4 mm: add WasActive page flag
Zcache could be ineffective if the compressed memory pool is full with
compressed inactive file pages and most of them will be never used again.

So we pick up pages from active file list only, those pages would probably
be accessed again. Compress them in memory can reduce the latency
significantly compared with rereading from disk.

When a file page is shrunk from active file list to inactive file list,
PageActive flag is also cleared.
So adding an extra WasActive page flag for zcache to know whether the
file page was shrunk from the active list.

Change-Id: Ida1f4db17075d1f6f825ef7ce2b3bae4eb799e3f
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Patch-mainline: linux-mm @ 2013-08-06 11:36:17
[vinmenon@codeaurora.org: trivial merge conflict fixes, checkpatch fixes,
fix the definitions of was_active page flag so that it does not create
compile time errors with CONFIG_CLEANCACHE disabled. Also remove the
unnecessary use of PG_was_active in PAGE_FLAGS_CHECK_AT_PREP. Since
was_active is a requirement for zcache, make the definitions dependent on
CONFIG_ZCACHE rather than CONFIG_CLEANCACHE.]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-05-31 15:27:11 -07:00
Vinayak Menon
44bd107fc9 mm: vmscan: fix the page state calculation in too_many_isolated
It is observed that sometimes multiple tasks get blocked in
the congestion_wait loop below, in shrink_inactive_list.

(__schedule) from [<c0a03328>]
(schedule_timeout) from [<c0a04940>]
(io_schedule_timeout) from [<c01d585c>]
(congestion_wait) from [<c01cc9d8>]
(shrink_inactive_list) from [<c01cd034>]
(shrink_zone) from [<c01cdd08>]
(try_to_free_pages) from [<c01c442c>]
(__alloc_pages_nodemask) from [<c01f1884>]
(new_slab) from [<c09fcf60>]
(__slab_alloc) from [<c01f1a6c>]

In one such instance, zone_page_state(zone, NR_ISOLATED_FILE)
had returned 14, zone_page_state(zone, NR_INACTIVE_FILE)
returned 92, and the gfp_flag was GFP_KERNEL which resulted
in too_many_isolated to return true. But one of the CPU pageset
vmstat diff had NR_ISOLATED_FILE as -14. As there weren't any more
update to per cpu pageset, the threshold wasn't met, and the
tasks were blocked in the congestion wait.

This patch uses zone_page_state_snapshot instead, but restricts
its usage to avoid performance penalty.

Change-Id: Iec767a548e524729c7ed79a92fe4718cdd08ce69
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-05-31 15:23:28 -07:00
Minchan Kim
87c855f150 mm: vmscan: reclaim highmem zone if buffer_heads is over limit
commit 7bf52fb891b64b8d61caf0b82060adb9db761aec upstream.

We have been reclaimed highmem zone if buffer_heads is over limit but
commit 6b4f7799c6 ("mm: vmscan: invoke slab shrinkers from
shrink_zone()") changed the behavior so it doesn't reclaim highmem zone
although buffer_heads is over the limit.  This patch restores the logic.

Fixes: 6b4f7799c6 ("mm: vmscan: invoke slab shrinkers from shrink_zone()")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04 14:48:49 -07:00
Vinayak Menon
2e21911abe mm: do not activate swap write failed pages
Sometime back a piece of code was added to activate
pages in pageout which failed to writeback. This was
done for the case of failed write to zram, with the
intention of reducing further zram writes. But this
does not make much sense because there can anyway be
other pages which the reclaim path can pick to swap
out.
And this particular logic has a problem. When a write
fails, the page is unlocked. Its locked again before
activating the page, but the page which is now in
swapcache can be brought back with its original mapping
through a fault, which can happen during this period.
This can result in random bugs, for e.g. when shrink_page_list
try to do try_to_free_swap. Here is one such case.
In this case PageSwapCache was cleared by the fault path.

"
zram: Error allocating memory for compressed page: 91433, size=4096
Write-error on swap-device (254:0:731464)
page:de866e80 count:3 mapcount:1 mapping:d5368941 index:0xb2ce5
flags: 0x80018(uptodate|dirty|swapbacked)
page dumped because: VM_BUG_ON_PAGE(!PageSwapCache(page))
"

CRs-Fixed: 988207
Change-Id: I26738d0f8dd3e2dfdb24c25edac24a7d968eeba0
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-25 16:03:35 -07:00
Vinayak Menon
e5ce54a9cb mm: swap: don't delay swap free for fast swap devices
There are couple of issues with swapcache usage when ZRAM is used
as swap device.
1) Kernel does a swap readahead which can be around 6 to 8 pages
depending on total ram, which is not required for zram since
accesses are fast.
2) Kernel delays the freeing up of swapcache expecting a later hit,
which again is useless in the case of zram.
3) This is not related to swapcache, but zram usage itself.
As mentioned in (2) kernel delays freeing of swapcache, but along with
that it delays zram compressed page free also. i.e. there can be 2 copies,
though one is compressed.

This patch addresses these issues using two new flags
QUEUE_FLAG_FAST and SWP_FAST, to indicate that accesses to the device
will be fast and cheap, and instructs the swap layer to free up
swap space agressively, and not to do read ahead.

Change-Id: I5d2d5176a5f9420300bb2f843f6ecbdb25ea80e4
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:52 -07:00
Liam Mark
8918861861 mm: vmscan: support setting of kswapd cpu affinity
Allow the kswapd cpu affinity to be configured.
There can be power benefits on certain targets when limiting kswapd
to run only on certain cores.

CRs-fixed: 752344
Change-Id: I8a83337ff313a7e0324361140398226a09f8be0f
Signed-off-by: Liam Mark <lmark@codeaurora.org>
[imaund@codeaurora.org: Resolved trivial context conflicts.]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2016-03-22 11:03:36 -07:00
Vinayak Menon
90863369e5 mm: vmscan: lock page on swap error in pageout
A workaround was added ealier to move a page to active
list if swapping to devices like zram fails. But this
can result in try_to_free_swap being called from
shrink_page_list, without a properly locked page.
Lock the page when we indicate to activate a page
in pageout().
Add a check to ensure that error is on swap, and
clear the error flag before moving the page to
active list.

CRs-fixed: 760049
Change-Id: I77a8bbd6ed13efdec943298fe9448412feeac176
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
2016-03-22 11:03:35 -07:00
Liam Mark
8a94faffd0 mm: vmscan: support complete shrinker reclaim
Ensure that shrinkers are given the option to completely drop
their caches even when their caches are smaller than the batch size.

This change helps improve memory headroom by ensuring that under
significant memory pressure shrinkers can drop all of their caches.

This change only attempts to more aggressively call the shrinkers
during background memory reclaim, inorder to avoid hurting the
perforamnce of direct memory reclaim.

Change-Id: I8dbc29c054add639e4810e36fd2c8a063e5c52f3
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:33 -07:00
Liam Mark
585690954e mm: vmscan: support equal reclaim for anon and file pages
When performing memory reclaim support treating anonymous and
file backed pages equally.

Swapping anonymous pages out to memory can be efficient enough
to justify treating anonymous and file backed pages equally.

CRs-Fixed: 648984
Change-Id: I6315b8557020d1e27a34225bb9cefbef1fb43266
Signed-off-by: Liam Mark <lmark@codeaurora.org>
2016-03-22 11:03:26 -07:00
Olav Haugan
80370b5f59 mm: vmscan: Move pages that fail swapout to LRU active list
Move pages that fail swapout to the LRU active list to reduce
pressure on swap device when swapping out is already failing.
This helps when using a pseudo swap device such as zram which
starts failing when memory is low.

Change-Id: Ib136cd0a744378aa93d837a24b9143ee818c80b3
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
2016-03-22 11:03:25 -07:00
Rebecca Schultz Zavin
b0e7a582b2 mm: vmscan: Add a debug file for shrinkers
This patch adds a debugfs file called "shrinker" when read this calls
all the shrinkers in the system with nr_to_scan set to zero and prints
the result.  These results are the number of objects the shrinkers have
available and can thus be used an indication of the total memory
that would be availble to the system if a shrink occurred.

Change-Id: Ied0ee7caff3d2fc1cb4bb839aaafee81b5b0b143
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
2016-02-16 13:54:12 -08:00
Mel Gorman
d0164adc89 mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Mel Gorman
e2b19197ff mm, page_alloc: remove unnecessary parameter from zone_watermark_ok_safe
Overall, the intent of this series is to remove the zonelist cache which
was introduced to avoid high overhead in the page allocator.  Once this is
done, it is necessary to reduce the cost of watermark checks.

The series starts with minor micro-optimisations.

Next it notes that GFP flags that affect watermark checks are abused.
__GFP_WAIT historically identified callers that could not sleep and could
access reserves.  This was later abused to identify callers that simply
prefer to avoid sleeping and have other options.  A patch distinguishes
between atomic callers, high-priority callers and those that simply wish
to avoid sleep.

The zonelist cache has been around for a long time but it is of dubious
merit with a lot of complexity and some issues that are explained.  The
most important issue is that a failed THP allocation can cause a zone to
be treated as "full".  This potentially causes unnecessary stalls, reclaim
activity or remote fallbacks.  The issues could be fixed but it's not
worth it.  The series places a small number of other micro-optimisations
on top before examining GFP flags watermarks.

High-order watermarks enforcement can cause high-order allocations to fail
even though pages are free.  The watermark checks both protect high-order
atomic allocations and make kswapd aware of high-order pages but there is
a much better way that can be handled using migrate types.  This series
uses page grouping by mobility to reserve pageblocks for high-order
allocations with the size of the reservation depending on demand.  kswapd
awareness is maintained by examining the free lists.  By patch 12 in this
series, there are no high-order watermark checks while preserving the
properties that motivated the introduction of the watermark checks.

This patch (of 10):

No user of zone_watermark_ok_safe() specifies alloc_flags.  This patch
removes the unnecessary parameter.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Linus Torvalds
2e3078af2c Merge branch 'akpm' (patches from Andrew)
Merge patch-bomb from Andrew Morton:

 - inotify tweaks

 - some ocfs2 updates (many more are awaiting review)

 - various misc bits

 - kernel/watchdog.c updates

 - Some of mm.  I have a huge number of MM patches this time and quite a
   lot of it is quite difficult and much will be held over to next time.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  selftests: vm: add tests for lock on fault
  mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage
  mm: introduce VM_LOCKONFAULT
  mm: mlock: add new mlock system call
  mm: mlock: refactor mlock, munlock, and munlockall code
  kasan: always taint kernel on report
  mm, slub, kasan: enable user tracking by default with KASAN=y
  kasan: use IS_ALIGNED in memory_is_poisoned_8()
  kasan: Fix a type conversion error
  lib: test_kasan: add some testcases
  kasan: update reference to kasan prototype repo
  kasan: move KASAN_SANITIZE in arch/x86/boot/Makefile
  kasan: various fixes in documentation
  kasan: update log messages
  kasan: accurately determine the type of the bad access
  kasan: update reported bug types for kernel memory accesses
  kasan: update reported bug types for not user nor kernel memory accesses
  mm/kasan: prevent deadlock in kasan reporting
  mm/kasan: don't use kasan shadow pointer in generic functions
  mm/kasan: MODULE_VADDR is not available on all archs
  ...
2015-11-05 23:10:54 -08:00
Alexandru Moise
d031a15791 mm/vmscan.c: fix types of some locals
In zone_reclaimable_pages(), `nr' is returned by a function which is
declared as returning "unsigned long", so declare it such.  Negative
values are meaningless here.

In zone_pagecache_reclaimable() we should also declare `delta' and
`nr_pagecache_reclaimable' as being unsigned longs because they're used to
store the values returned by zone_page_state() and
zone_unmapped_file_pages() which also happen to return unsigned integers.

[akpm@linux-foundation.org: make zone_pagecache_reclaimable() return ulong rather than long]
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Yaowei Bai
42e2e45777 mm/vmscan: make inactive_anon/file_is_low return bool
Make inactive_anon/file_is_low return bool due to these particular
functions only using either one or zero as their return value.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Yaowei Bai
29d06bbb41 mm/vmscan: make inactive_anon_is_low_global return directly
Delete unnecessary if to let inactive_anon_is_low_global return
directly.

No functional changes.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Linus Torvalds
69234acee5 Merge branch 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "The cgroup core saw several significant updates this cycle:

   - percpu_rwsem for threadgroup locking is reinstated.  This was
     temporarily dropped due to down_write latency issues.  Oleg's
     rework of percpu_rwsem which is scheduled to be merged in this
     merge window resolves the issue.

   - On the v2 hierarchy, when controllers are enabled and disabled, all
     operations are atomic and can fail and revert cleanly.  This allows
     ->can_attach() failure which is necessary for cpu RT slices.

   - Tasks now stay associated with the original cgroups after exit
     until released.  This allows tracking resources held by zombies
     (e.g.  pids) and makes it easy to find out where zombies came from
     on the v2 hierarchy.  The pids controller was broken before these
     changes as zombies escaped the limits; unfortunately, updating this
     behavior required too many invasive changes and I don't think it's
     a good idea to backport them, so the pids controller on 4.3, the
     first version which included the pids controller, will stay broken
     at least until I'm sure about the cgroup core changes.

   - Optimization of a couple common tests using static_key"

* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits)
  cgroup: fix race condition around termination check in css_task_iter_next()
  blkcg: don't create "io.stat" on the root cgroup
  cgroup: drop cgroup__DEVEL__legacy_files_on_dfl
  cgroup: replace error handling in cgroup_init() with WARN_ON()s
  cgroup: add cgroup_subsys->free() method and use it to fix pids controller
  cgroup: keep zombies associated with their original cgroups
  cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock
  cgroup: don't hold css_set_rwsem across css task iteration
  cgroup: reorganize css_task_iter functions
  cgroup: factor out css_set_move_task()
  cgroup: keep css_set and task lists in chronological order
  cgroup: make cgroup_destroy_locked() test cgroup_is_populated()
  cgroup: make css_sets pin the associated cgroups
  cgroup: relocate cgroup_[try]get/put()
  cgroup: move check_for_release() invocation
  cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
  cgroup: make cgroup->nr_populated count the number of populated css_sets
  cgroup: remove an unused parameter from cgroup_task_migrate()
  cgroup: fix too early usage of static_branch_disable()
  cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically
  ...
2015-11-05 14:51:32 -08:00
Vladimir Davydov
d5028f9f7d vmscan: fix sane_reclaim helper for legacy memcg
The sane_reclaim() helper is supposed to return false for memcg reclaim
if the legacy hierarchy is used, because the latter lacks dirty
throttling mechanism, and so it did before it was accidentally broken by
commit 33398cf2f3 ("memcg: export struct mem_cgroup").  Fix it.

Fixes: 33398cf2f3 ("memcg: export struct mem_cgroup")
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22 15:09:53 -07:00
Hugh Dickins
7fadc82022 mm, vmscan: unlock page while waiting on writeback
This is merely a politeness: I've not found that shrink_page_list()
leads to deadlock with the page it holds locked across
wait_on_page_writeback(); but nevertheless, why hold others off by
keeping the page locked there?

And while we're at it: remove the mistaken "not " from the commentary on
this Case 3 (and a distracting blank line from Case 2, if I may).

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Jaewon Kim
c54839a722 vmscan: fix increasing nr_isolated incurred by putback unevictable pages
reclaim_clean_pages_from_list() assumes that shrink_page_list() returns
number of pages removed from the candidate list.  But shrink_page_list()
puts back mlocked pages without passing it to caller and without
counting as nr_reclaimed.  This increases nr_isolated.

To fix this, this patch changes shrink_page_list() to pass unevictable
pages back to caller.  Caller will take care those pages.

Minchan said:

It fixes two issues.

1. With unevictable page, cma_alloc will be successful.

Exactly speaking, cma_alloc of current kernel will fail due to
unevictable pages.

2. fix leaking of NR_ISOLATED counter of vmstat

With it, too_many_isolated works.  Otherwise, it could make hang until
the process get SIGKILL.

Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Vladimir Davydov
0b802f101d mm: vmscan: never isolate more pages than necessary
If transparent huge pages are enabled, we can isolate many more pages
than we actually need to scan, because we count both single and huge
pages equally in isolate_lru_pages().

Since commit 5bc7b8aca9 ("mm: thp: add split tail pages to shrink
page list in page reclaim"), we scan all the tail pages immediately
after a huge page split (see shrink_page_list()).  As a result, we can
reclaim up to SWAP_CLUSTER_MAX * HPAGE_PMD_NR (512 MB) in one run!

This is easy to catch on memcg reclaim with zswap enabled.  The latter
makes swapout instant so that if we happen to scan an unreferenced huge
page we will evict both its head and tail pages immediately, which is
likely to result in excessive reclaim.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Michal Hocko
33398cf2f3 memcg: export struct mem_cgroup
mem_cgroup structure is defined in mm/memcontrol.c currently which means
that the code outside of this file has to use external API even for
trivial access stuff.

This patch exports mm_struct with its dependencies and makes some of the
exported functions inlines.  This even helps to reduce the code size a bit
(make defconfig + CONFIG_MEMCG=y)

  text		data    bss     dec     	 hex 	filename
  12355346        1823792 1089536 15268674         e8fb42 vmlinux.before
  12354970        1823792 1089536 15268298         e8f9ca vmlinux.after

This is not much (370B) but better than nothing.

We also save a function call in some hot paths like callers of
mem_cgroup_count_vm_event which is used for accounting.

The patch doesn't introduce any functional changes.

[vdavykov@parallels.com: inline memcg_kmem_is_active]
[vdavykov@parallels.com: do not expose type outside of CONFIG_MEMCG]
[akpm@linux-foundation.org: memcontrol.h needs eventfd.h for eventfd_ctx]
[akpm@linux-foundation.org: export mem_cgroup_from_task() to modules]
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.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>
2015-09-08 15:35:28 -07:00
Mel Gorman
d950c9477d mm: defer flush of writable TLB entries
If a PTE is unmapped and it's dirty then it was writable recently.  Due to
deferred TLB flushing, it's best to assume a writable TLB cache entry
exists.  With that assumption, the TLB must be flushed before any IO can
start or the page is freed to avoid lost writes or data corruption.  This
patch defers flushing of potentially writable TLBs as long as possible.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Mel Gorman
72b252aed5 mm: send one IPI per CPU to TLB flush all entries after unmapping pages
An IPI is sent to flush remote TLBs when a page is unmapped that was
potentially accesssed by other CPUs.  There are many circumstances where
this happens but the obvious one is kswapd reclaiming pages belonging to a
running process as kswapd and the task are likely running on separate
CPUs.

On small machines, this is not a significant problem but as machine gets
larger with more cores and more memory, the cost of these IPIs can be
high.  This patch uses a simple structure that tracks CPUs that
potentially have TLB entries for pages being unmapped.  When the unmapping
is complete, the full TLB is flushed on the assumption that a refill cost
is lower than flushing individual entries.

Architectures wishing to do this must give the following guarantee.

        If a clean page is unmapped and not immediately flushed, the
        architecture must guarantee that a write to that linear address
        from a CPU with a cached TLB entry will trap a page fault.

This is essentially what the kernel already depends on but the window is
much larger with this patch applied and is worth highlighting.  The
architecture should consider whether the cost of the full TLB flush is
higher than sending an IPI to flush each individual entry.  An additional
architecture helper called flush_tlb_local is required.  It's a trivial
wrapper with some accounting in the x86 case.

The impact of this patch depends on the workload as measuring any benefit
requires both mapped pages co-located on the LRU and memory pressure.  The
case with the biggest impact is multiple processes reading mapped pages
taken from the vm-scalability test suite.  The test case uses NR_CPU
readers of mapped files that consume 10*RAM.

Linear mapped reader on a 4-node machine with 64G RAM and 48 CPUs

                                           4.2.0-rc1          4.2.0-rc1
                                             vanilla       flushfull-v7
Ops lru-file-mmap-read-elapsed      159.62 (  0.00%)   120.68 ( 24.40%)
Ops lru-file-mmap-read-time_range    30.59 (  0.00%)     2.80 ( 90.85%)
Ops lru-file-mmap-read-time_stddv     6.70 (  0.00%)     0.64 ( 90.38%)

           4.2.0-rc1    4.2.0-rc1
             vanilla flushfull-v7
User          581.00       611.43
System       5804.93      4111.76
Elapsed       161.03       122.12

This is showing that the readers completed 24.40% faster with 29% less
system CPU time.  From vmstats, it is known that the vanilla kernel was
interrupted roughly 900K times per second during the steady phase of the
test and the patched kernel was interrupts 180K times per second.

The impact is lower on a single socket machine.

                                           4.2.0-rc1          4.2.0-rc1
                                             vanilla       flushfull-v7
Ops lru-file-mmap-read-elapsed       25.33 (  0.00%)    20.38 ( 19.54%)
Ops lru-file-mmap-read-time_range     0.91 (  0.00%)     1.44 (-58.24%)
Ops lru-file-mmap-read-time_stddv     0.28 (  0.00%)     0.47 (-65.34%)

           4.2.0-rc1    4.2.0-rc1
             vanilla flushfull-v7
User           58.09        57.64
System        111.82        76.56
Elapsed        27.29        22.55

It's still a noticeable improvement with vmstat showing interrupts went
from roughly 500K per second to 45K per second.

The patch will have no impact on workloads with no memory pressure or have
relatively few mapped pages.  It will have an unpredictable impact on the
workload running on the CPU being flushed as it'll depend on how many TLB
entries need to be refilled and how long that takes.  Worst case, the TLB
will be completely cleared of active entries when the target PFNs were not
resident at all.

[sasha.levin@oracle.com: trace tlb flush after disabling preemption in try_to_unmap_flush]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Michal Hocko
ecf5fc6e96 mm, vmscan: Do not wait for page writeback for GFP_NOFS allocations
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384e9d ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f44fc ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: stable@vger.kernel.org # 3.9+
[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f44fc ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-05 10:49:38 +02:00
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
Zhihui Zhang
95bbc0c721 mm: rename RECLAIM_SWAP to RECLAIM_UNMAP
The name SWAP implies that we are dealing with anonymous pages only.  In
fact, the original patch that introduced the min_unmapped_ratio logic
was to fix an issue related to file pages.  Rename it to RECLAIM_UNMAP
to match what does.

Historically, commit a6dc60f897 ("vmscan: rename sc.may_swap to
may_unmap") renamed .may_swap to .may_unmap, leaving RECLAIM_SWAP
behind.  commit 2e2e425989 ("vmscan,memcg: reintroduce sc->may_swap")
reintroduced .may_swap for memory controller.

Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:42 -07:00
Nishanth Aravamudan
f012a84aff mm: vmscan: do not throttle based on pfmemalloc reserves if node has no reclaimable pages
Based upon 675becce15 ("mm: vmscan: do not throttle based on pfmemalloc
reserves if node has no ZONE_NORMAL") from Mel.

We have a system with the following topology:

# numactl -H
available: 3 nodes (0,2-3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31
node 0 size: 28273 MB
node 0 free: 27323 MB
node 2 cpus:
node 2 size: 16384 MB
node 2 free: 0 MB
node 3 cpus: 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
node 3 size: 30533 MB
node 3 free: 13273 MB
node distances:
node   0   2   3
  0:  10  20  20
  2:  20  10  20
  3:  20  20  10

Node 2 has no free memory, because:
# cat /sys/devices/system/node/node2/hugepages/hugepages-16777216kB/nr_hugepages
1

This leads to the following zoneinfo:

Node 2, zone      DMA
  pages free     0
        min      1840
        low      2300
        high     2760
        scanned  0
        spanned  262144
        present  262144
        managed  262144
...
  all_unreclaimable: 1

If one then attempts to allocate some normal 16M hugepages via

echo 37 > /proc/sys/vm/nr_hugepages

The echo never returns and kswapd2 consumes CPU cycles.

This is because throttle_direct_reclaim ends up calling
wait_event(pfmemalloc_wait, pfmemalloc_watermark_ok...).
pfmemalloc_watermark_ok() in turn checks all zones on the node if there
are any reserves, and if so, then indicates the watermarks are ok, by
seeing if there are sufficient free pages.

675becce15 added a condition already for memoryless nodes.  In this case,
though, the node has memory, it is just all consumed (and not
reclaimable).  Effectively, though, the result is the same on this call to
pfmemalloc_watermark_ok() and thus seems like a reasonable additional
condition.

With this change, the afore-mentioned 16M hugepage allocation attempt
succeeds and correctly round-robins between Nodes 1 and 3.

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Anton Blanchard <anton@samba.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:42 -07:00
Tejun Heo
97c9341f72 mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
Because writeback wasn't cgroup aware before, the usual dirty
throttling mechanism in balance_dirty_pages() didn't work for
processes under memcg limit.  The writeback path didn't know how much
memory is available or how fast the dirty pages are being written out
for a given memcg and balance_dirty_pages() didn't have any measure of
IO back pressure for the memcg.

To work around the issue, memcg implemented an ad-hoc dirty throttling
mechanism in the direct reclaim path by stalling on pages under
writeback which are encountered during direct reclaim scan.  This is
rather ugly and crude - none of the configurability, fairness, or
bandwidth-proportional distribution of the normal path.

The previous patches implemented proper memcg aware dirty throttling
when cgroup writeback is in use making the ad-hoc mechanism
unnecessary.  This patch disables direct reclaim stalling for such
case.

Note: I disabled the parts which seemed obvious and it behaves fine
      while testing but my understanding of this code path is
      rudimentary and it's quite possible that I got something wrong.
      Please let me know if I got some wrong or more global_reclaim()
      sites should be updated.

v2: The original patch removed the direct stalling mechanism which
    breaks legacy hierarchies.  Conditionalize instead of removing.

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>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:38:13 -06:00
Tejun Heo
703c270887 writeback: implement and use inode_congested()
In several places, bdi_congested() and its wrappers are used to
determine whether more IOs should be issued.  With cgroup writeback
support, this question can't be answered solely based on the bdi
(backing_dev_info).  It's dependent on whether the filesystem and bdi
support cgroup writeback and the blkcg the inode is associated with.

This patch implements inode_congested() and its wrappers which take
@inode and determines the congestion state considering cgroup
writeback.  The new functions replace bdi_*congested() calls in places
where the query is about specific inode and task.

There are several filesystem users which also fit this criteria but
they should be updated when each filesystem implements cgroup
writeback support.

v2: Now that a given inode is associated with only one wb, congestion
    state can be determined independent from the asking task.  Drop
    @task.  Spotted by Vivek.  Also, converted to take @inode instead
    of @mapping and renamed to inode_congested().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -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
Linus Torvalds
818099574b Merge branch 'akpm' (patches from Andrew)
Merge third set of updates from Andrew Morton:

 - the rest of MM

   [ This includes getting rid of the numa hinting bits, in favor of
     just generic protnone logic.  Yay.     - Linus ]

 - core kernel

 - procfs

 - some of lib/ (lots of lib/ material this time)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (104 commits)
  lib/lcm.c: replace include
  lib/percpu_ida.c: remove redundant includes
  lib/strncpy_from_user.c: replace module.h include
  lib/stmp_device.c: replace module.h include
  lib/sort.c: move include inside #if 0
  lib/show_mem.c: remove redundant include
  lib/radix-tree.c: change to simpler include
  lib/plist.c: remove redundant include
  lib/nlattr.c: remove redundant include
  lib/kobject_uevent.c: remove redundant include
  lib/llist.c: remove redundant include
  lib/md5.c: simplify include
  lib/list_sort.c: rearrange includes
  lib/genalloc.c: remove redundant include
  lib/idr.c: remove redundant include
  lib/halfmd4.c: simplify includes
  lib/dynamic_queue_limits.c: simplify includes
  lib/sort.c: use simpler includes
  lib/interval_tree.c: simplify includes
  hexdump: make it return number of bytes placed in buffer
  ...
2015-02-12 18:54:28 -08:00
Vladimir Davydov
cb731d6c62 vmscan: per memory cgroup slab shrinkers
This patch adds SHRINKER_MEMCG_AWARE flag.  If a shrinker has this flag
set, it will be called per memory cgroup.  The memory cgroup to scan
objects from is passed in shrink_control->memcg.  If the memory cgroup
is NULL, a memcg aware shrinker is supposed to scan objects from the
global list.  Unaware shrinkers are only called on global pressure with
memcg=NULL.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:09 -08:00
Linus Torvalds
6bec003528 Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block
Pull backing device changes from Jens Axboe:
 "This contains a cleanup of how the backing device is handled, in
  preparation for a rework of the life time rules.  In this part, the
  most important change is to split the unrelated nommu mmap flags from
  it, but also removing a backing_dev_info pointer from the
  address_space (and inode), and a cleanup of other various minor bits.

  Christoph did all the work here, I just fixed an oops with pages that
  have a swap backing.  Arnd fixed a missing export, and Oleg killed the
  lustre backing_dev_info from staging.  Last patch was from Al,
  unexporting parts that are now no longer needed outside"

* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
  Make super_blocks and sb_lock static
  mtd: export new mtd_mmap_capabilities
  fs: make inode_to_bdi() handle NULL inode
  staging/lustre/llite: get rid of backing_dev_info
  fs: remove default_backing_dev_info
  fs: don't reassign dirty inodes to default_backing_dev_info
  nfs: don't call bdi_unregister
  ceph: remove call to bdi_unregister
  fs: remove mapping->backing_dev_info
  fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
  nilfs2: set up s_bdi like the generic mount_bdev code
  block_dev: get bdev inode bdi directly from the block device
  block_dev: only write bdev inode on close
  fs: introduce f_op->mmap_capabilities for nommu mmap support
  fs: kill BDI_CAP_SWAP_BACKED
  fs: deduplicate noop_backing_dev_info
2015-02-12 13:50:21 -08:00
Johannes Weiner
241994ed86 mm: memcontrol: default hierarchy interface for memory
Introduce the basic control files to account, partition, and limit
memory using cgroups in default hierarchy mode.

This interface versioning allows us to address fundamental design
issues in the existing memory cgroup interface, further explained
below.  The old interface will be maintained indefinitely, but a
clearer model and improved workload performance should encourage
existing users to switch over to the new one eventually.

The control files are thus:

  - memory.current shows the current consumption of the cgroup and its
    descendants, in bytes.

  - memory.low configures the lower end of the cgroup's expected
    memory consumption range.  The kernel considers memory below that
    boundary to be a reserve - the minimum that the workload needs in
    order to make forward progress - and generally avoids reclaiming
    it, unless there is an imminent risk of entering an OOM situation.

  - memory.high configures the upper end of the cgroup's expected
    memory consumption range.  A cgroup whose consumption grows beyond
    this threshold is forced into direct reclaim, to work off the
    excess and to throttle new allocations heavily, but is generally
    allowed to continue and the OOM killer is not invoked.

  - memory.max configures the hard maximum amount of memory that the
    cgroup is allowed to consume before the OOM killer is invoked.

  - memory.events shows event counters that indicate how often the
    cgroup was reclaimed while below memory.low, how often it was
    forced to reclaim excess beyond memory.high, how often it hit
    memory.max, and how often it entered OOM due to memory.max.  This
    allows users to identify configuration problems when observing a
    degradation in workload performance.  An overcommitted system will
    have an increased rate of low boundary breaches, whereas increased
    rates of high limit breaches, maximum hits, or even OOM situations
    will indicate internally overcommitted cgroups.

For existing users of memory cgroups, the following deviations from
the current interface are worth pointing out and explaining:

  - The original lower boundary, the soft limit, is defined as a limit
    that is per default unset.  As a result, the set of cgroups that
    global reclaim prefers is opt-in, rather than opt-out.  The costs
    for optimizing these mostly negative lookups are so high that the
    implementation, despite its enormous size, does not even provide
    the basic desirable behavior.  First off, the soft limit has no
    hierarchical meaning.  All configured groups are organized in a
    global rbtree and treated like equal peers, regardless where they
    are located in the hierarchy.  This makes subtree delegation
    impossible.  Second, the soft limit reclaim pass is so aggressive
    that it not just introduces high allocation latencies into the
    system, but also impacts system performance due to overreclaim, to
    the point where the feature becomes self-defeating.

    The memory.low boundary on the other hand is a top-down allocated
    reserve.  A cgroup enjoys reclaim protection when it and all its
    ancestors are below their low boundaries, which makes delegation
    of subtrees possible.  Secondly, new cgroups have no reserve per
    default and in the common case most cgroups are eligible for the
    preferred reclaim pass.  This allows the new low boundary to be
    efficiently implemented with just a minor addition to the generic
    reclaim code, without the need for out-of-band data structures and
    reclaim passes.  Because the generic reclaim code considers all
    cgroups except for the ones running low in the preferred first
    reclaim pass, overreclaim of individual groups is eliminated as
    well, resulting in much better overall workload performance.

  - The original high boundary, the hard limit, is defined as a strict
    limit that can not budge, even if the OOM killer has to be called.
    But this generally goes against the goal of making the most out of
    the available memory.  The memory consumption of workloads varies
    during runtime, and that requires users to overcommit.  But doing
    that with a strict upper limit requires either a fairly accurate
    prediction of the working set size or adding slack to the limit.
    Since working set size estimation is hard and error prone, and
    getting it wrong results in OOM kills, most users tend to err on
    the side of a looser limit and end up wasting precious resources.

    The memory.high boundary on the other hand can be set much more
    conservatively.  When hit, it throttles allocations by forcing
    them into direct reclaim to work off the excess, but it never
    invokes the OOM killer.  As a result, a high boundary that is
    chosen too aggressively will not terminate the processes, but
    instead it will lead to gradual performance degradation.  The user
    can monitor this and make corrections until the minimal memory
    footprint that still gives acceptable performance is found.

    In extreme cases, with many concurrent allocations and a complete
    breakdown of reclaim progress within the group, the high boundary
    can be exceeded.  But even then it's mostly better to satisfy the
    allocation from the slack available in other groups or the rest of
    the system than killing the group.  Otherwise, memory.max is there
    to limit this type of spillover and ultimately contain buggy or
    even malicious applications.

  - The original control file names are unwieldy and inconsistent in
    many different ways.  For example, the upper boundary hit count is
    exported in the memory.failcnt file, but an OOM event count has to
    be manually counted by listening to memory.oom_control events, and
    lower boundary / soft limit events have to be counted by first
    setting a threshold for that value and then counting those events.
    Also, usage and limit files encode their units in the filename.
    That makes the filenames very long, even though this is not
    information that a user needs to be reminded of every time they
    type out those names.

    To address these naming issues, as well as to signal clearly that
    the new interface carries a new configuration model, the naming
    conventions in it necessarily differ from the old interface.

  - The original limit files indicate the state of an unset limit with
    a very high number, and a configured limit can be unset by echoing
    -1 into those files.  But that very high number is implementation
    and architecture dependent and not very descriptive.  And while -1
    can be understood as an underflow into the highest possible value,
    -2 or -10M etc. do not work, so it's not inconsistent.

    memory.low, memory.high, and memory.max will use the string
    "infinity" to indicate and set the highest possible value.

[akpm@linux-foundation.org: use seq_puts() for basic strings]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:02 -08:00
Vladimir Davydov
90cbc25088 vmscan: force scan offline memory cgroups
Since commit b2052564e6 ("mm: memcontrol: continue cache reclaim from
offlined groups") pages charged to a memory cgroup are not reparented when
the cgroup is removed.  Instead, they are supposed to be reclaimed in a
regular way, along with pages accounted to online memory cgroups.

However, an lruvec of an offline memory cgroup will sooner or later get so
small that it will be scanned only at low scan priorities (see
get_scan_count()).  Therefore, if there are enough reclaimable pages in
big lruvecs, pages accounted to offline memory cgroups will never be
scanned at all, wasting memory.

Fix this by unconditionally forcing scanning dead lruvecs from kswapd.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.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>
2015-02-11 17:06:02 -08:00
Vlastimil Babka
cfc5115579 mm, vmscan: wake up all pfmemalloc-throttled processes at once
Kswapd in balance_pgdate() currently uses wake_up() on processes waiting
in throttle_direct_reclaim(), which only wakes up a single process.  This
might leave processes waiting for longer than necessary, until the check
is reached in the next loop iteration.  Processes might also be left
waiting if zone was fully balanced in single iteration.  Note that the
comment in balance_pgdat() also says "Wake them", so waking up a single
process does not seem intentional.

Thus, replace wake_up() with wake_up_all().

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:01 -08:00
Michael S. Tsirkin
17636faada mm/vmscan: fix highidx argument type
for_each_zone_zonelist_nodemask wants an enum zone_type argument, but is
passed gfp_t:

  mm/vmscan.c:2658:9:    expected int enum zone_type [signed] highest_zoneidx
  mm/vmscan.c:2658:9:    got restricted gfp_t [usertype] gfp_mask
  mm/vmscan.c:2658:9: warning: incorrect type in argument 2 (different base types)
  mm/vmscan.c:2658:9:    expected int enum zone_type [signed] highest_zoneidx
  mm/vmscan.c:2658:9:    got restricted gfp_t [usertype] gfp_mask

convert argument to the correct type.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-26 13:37:18 -08:00
Christoph Hellwig
de1414a654 fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
Now that we got rid of the bdi abuse on character devices we can always use
sb->s_bdi to get at the backing_dev_info for a file, except for the block
device special case.  Export inode_to_bdi and replace uses of
mapping->backing_dev_info with it to prepare for the removal of
mapping->backing_dev_info.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:03:04 -07:00
Vlastimil Babka
9e5e366172 mm, vmscan: prevent kswapd livelock due to pfmemalloc-throttled process being killed
Charles Shirron and Paul Cassella from Cray Inc have reported kswapd
stuck in a busy loop with nothing left to balance, but
kswapd_try_to_sleep() failing to sleep.  Their analysis found the cause
to be a combination of several factors:

1. A process is waiting in throttle_direct_reclaim() on pgdat->pfmemalloc_wait

2. The process has been killed (by OOM in this case), but has not yet been
   scheduled to remove itself from the waitqueue and die.

3. kswapd checks for throttled processes in prepare_kswapd_sleep():

        if (waitqueue_active(&pgdat->pfmemalloc_wait)) {
                wake_up(&pgdat->pfmemalloc_wait);
		return false; // kswapd will not go to sleep
	}

   However, for a process that was already killed, wake_up() does not remove
   the process from the waitqueue, since try_to_wake_up() checks its state
   first and returns false when the process is no longer waiting.

4. kswapd is running on the same CPU as the only CPU that the process is
   allowed to run on (through cpus_allowed, or possibly single-cpu system).

5. CONFIG_PREEMPT_NONE=y kernel is used. If there's nothing to balance, kswapd
   encounters no voluntary preemption points and repeatedly fails
   prepare_kswapd_sleep(), blocking the process from running and removing
   itself from the waitqueue, which would let kswapd sleep.

So, the source of the problem is that we prevent kswapd from going to
sleep until there are processes waiting on the pfmemalloc_wait queue,
and a process waiting on a queue is guaranteed to be removed from the
queue only when it gets scheduled.  This was done to make sure that no
process is left sleeping on pfmemalloc_wait when kswapd itself goes to
sleep.

However, it isn't necessary to postpone kswapd sleep until the
pfmemalloc_wait queue actually empties.  To prevent processes from being
left sleeping, it's actually enough to guarantee that all processes
waiting on pfmemalloc_wait queue have been woken up by the time we put
kswapd to sleep.

This patch therefore fixes this issue by substituting 'wake_up' with
'wake_up_all' and removing 'return false' in the code snippet from
prepare_kswapd_sleep() above.  Note that if any process puts itself in
the queue after this waitqueue_active() check, or after the wake up
itself, it means that the process will also wake up kswapd - and since
we are under prepare_to_wait(), the wake up won't be missed.  Also we
update the comment prepare_kswapd_sleep() to hopefully more clearly
describe the races it is preventing.

Fixes: 5515061d22 ("mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org>	[3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-08 15:10:52 -08:00
Johannes Weiner
6b4f7799c6 mm: vmscan: invoke slab shrinkers from shrink_zone()
The slab shrinkers are currently invoked from the zonelist walkers in
kswapd, direct reclaim, and zone reclaim, all of which roughly gauge the
eligible LRU pages and assemble a nodemask to pass to NUMA-aware
shrinkers, which then again have to walk over the nodemask.  This is
redundant code, extra runtime work, and fairly inaccurate when it comes to
the estimation of actually scannable LRU pages.  The code duplication will
only get worse when making the shrinkers cgroup-aware and requiring them
to have out-of-band cgroup hierarchy walks as well.

Instead, invoke the shrinkers from shrink_zone(), which is where all
reclaimers end up, to avoid this duplication.

Take the count for eligible LRU pages out of get_scan_count(), which
considers many more factors than just the availability of swap space, like
zone_reclaimable_pages() currently does.  Accumulate the number over all
visited lruvecs to get the per-zone value.

Some nodes have multiple zones due to memory addressing restrictions.  To
avoid putting too much pressure on the shrinkers, only invoke them once
for each such node, using the class zone of the allocation as the pivot
zone.

For now, this integrates the slab shrinking better into the reclaim logic
and gets rid of duplicative invocations from kswapd, direct reclaim, and
zone reclaim.  It also prepares for cgroup-awareness, allowing
memcg-capable shrinkers to be added at the lruvec level without much
duplication of both code and runtime work.

This changes kswapd behavior, which used to invoke the shrinkers for each
zone, but with scan ratios gathered from the entire node, resulting in
meaningless pressure quantities on multi-zone nodes.

Zone reclaim behavior also changes.  It used to shrink slabs until the
same amount of pages were shrunk as were reclaimed from the LRUs.  Now it
merely invokes the shrinkers once with the zone's scan ratio, which makes
the shrinkers go easier on caches that implement aging and would prefer
feeding back pressure from recently used slab objects to unused LRU pages.

[vdavydov@parallels.com: assure class zone is populated]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:48 -08:00
Linus Torvalds
2756d373a3 Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup update from Tejun Heo:
 "cpuset got simplified a bit.  cgroup core got a fix on unified
  hierarchy and grew some effective css related interfaces which will be
  used for blkio support for writeback IO traffic which is currently
  being worked on"

* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: implement cgroup_get_e_css()
  cgroup: add cgroup_subsys->css_e_css_changed()
  cgroup: add cgroup_subsys->css_released()
  cgroup: fix the async css offline wait logic in cgroup_subtree_control_write()
  cgroup: restructure child_subsys_mask handling in cgroup_subtree_control_write()
  cgroup: separate out cgroup_calc_child_subsys_mask() from cgroup_refresh_child_subsys_mask()
  cpuset: lock vs unlock typo
  cpuset: simplify cpuset_node_allowed API
  cpuset: convert callback_mutex to a spinlock
2014-12-11 18:57:19 -08:00