Commit Graph

986 Commits

Author SHA1 Message Date
xiaofeng
35dafe72dd ANDROID: vendor_hooks: tune reclaim swappiness or scan type
Add hooks for reclaim

Bug: 185438290
Change-Id: Ib9eec302b1df4da7e98c77b94541af28c34a8613
Signed-off-by: xiaofeng <xiaofeng5@xiaomi.com>
2021-04-15 23:08:29 +00:00
Greg Kroah-Hartman
d8c7f0a3cd Merge 5.10.20 into android12-5.10
Changes in 5.10.20
	vmlinux.lds.h: add DWARF v5 sections
	vdpa/mlx5: fix param validation in mlx5_vdpa_get_config()
	debugfs: be more robust at handling improper input in debugfs_lookup()
	debugfs: do not attempt to create a new file before the filesystem is initalized
	scsi: libsas: docs: Remove notify_ha_event()
	scsi: qla2xxx: Fix mailbox Ch erroneous error
	kdb: Make memory allocations more robust
	w1: w1_therm: Fix conversion result for negative temperatures
	PCI: qcom: Use PHY_REFCLK_USE_PAD only for ipq8064
	PCI: Decline to resize resources if boot config must be preserved
	virt: vbox: Do not use wait_event_interruptible when called from kernel context
	bfq: Avoid false bfq queue merging
	ALSA: usb-audio: Fix PCM buffer allocation in non-vmalloc mode
	MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section
	vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y
	random: fix the RNDRESEEDCRNG ioctl
	ALSA: pcm: Call sync_stop at disconnection
	ALSA: pcm: Assure sync with the pending stop operation at suspend
	ALSA: pcm: Don't call sync_stop if it hasn't been stopped
	drm/i915/gt: One more flush for Baytrail clear residuals
	ath10k: Fix error handling in case of CE pipe init failure
	Bluetooth: btqcomsmd: Fix a resource leak in error handling paths in the probe function
	Bluetooth: hci_uart: Fix a race for write_work scheduling
	Bluetooth: Fix initializing response id after clearing struct
	arm64: dts: renesas: beacon kit: Fix choppy Bluetooth Audio
	arm64: dts: renesas: beacon: Fix audio-1.8V pin enable
	ARM: dts: exynos: correct PMIC interrupt trigger level on Artik 5
	ARM: dts: exynos: correct PMIC interrupt trigger level on Monk
	ARM: dts: exynos: correct PMIC interrupt trigger level on Rinato
	ARM: dts: exynos: correct PMIC interrupt trigger level on Spring
	ARM: dts: exynos: correct PMIC interrupt trigger level on Arndale Octa
	ARM: dts: exynos: correct PMIC interrupt trigger level on Odroid XU3 family
	arm64: dts: exynos: correct PMIC interrupt trigger level on TM2
	arm64: dts: exynos: correct PMIC interrupt trigger level on Espresso
	memory: mtk-smi: Fix PM usage counter unbalance in mtk_smi ops
	Bluetooth: hci_qca: Fix memleak in qca_controller_memdump
	staging: vchiq: Fix bulk userdata handling
	staging: vchiq: Fix bulk transfers on 64-bit builds
	arm64: dts: qcom: msm8916-samsung-a5u: Fix iris compatible
	net: stmmac: dwmac-meson8b: fix enabling the timing-adjustment clock
	bpf: Add bpf_patch_call_args prototype to include/linux/bpf.h
	bpf: Avoid warning when re-casting __bpf_call_base into __bpf_call_base_args
	firmware: arm_scmi: Fix call site of scmi_notification_exit
	arm64: dts: allwinner: A64: properly connect USB PHY to port 0
	arm64: dts: allwinner: H6: properly connect USB PHY to port 0
	arm64: dts: allwinner: Drop non-removable from SoPine/LTS SD card
	arm64: dts: allwinner: H6: Allow up to 150 MHz MMC bus frequency
	arm64: dts: allwinner: A64: Limit MMC2 bus frequency to 150 MHz
	arm64: dts: qcom: msm8916-samsung-a2015: Fix sensors
	cpufreq: brcmstb-avs-cpufreq: Free resources in error path
	cpufreq: brcmstb-avs-cpufreq: Fix resource leaks in ->remove()
	arm64: dts: rockchip: rk3328: Add clock_in_out property to gmac2phy node
	ACPICA: Fix exception code class checks
	usb: gadget: u_audio: Free requests only after callback
	arm64: dts: qcom: sdm845-db845c: Fix reset-pin of ov8856 node
	soc: qcom: socinfo: Fix an off by one in qcom_show_pmic_model()
	soc: ti: pm33xx: Fix some resource leak in the error handling paths of the probe function
	staging: media: atomisp: Fix size_t format specifier in hmm_alloc() debug statemenet
	Bluetooth: drop HCI device reference before return
	Bluetooth: Put HCI device if inquiry procedure interrupts
	memory: ti-aemif: Drop child node when jumping out loop
	ARM: dts: Configure missing thermal interrupt for 4430
	usb: dwc2: Do not update data length if it is 0 on inbound transfers
	usb: dwc2: Abort transaction after errors with unknown reason
	usb: dwc2: Make "trimming xfer length" a debug message
	staging: rtl8723bs: wifi_regd.c: Fix incorrect number of regulatory rules
	x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too
	arm64: dts: renesas: beacon: Fix EEPROM compatible value
	can: mcp251xfd: mcp251xfd_probe(): fix errata reference
	ARM: dts: armada388-helios4: assign pinctrl to LEDs
	ARM: dts: armada388-helios4: assign pinctrl to each fan
	arm64: dts: armada-3720-turris-mox: rename u-boot mtd partition to a53-firmware
	opp: Correct debug message in _opp_add_static_v2()
	Bluetooth: btusb: Fix memory leak in btusb_mtk_wmt_recv
	soc: qcom: ocmem: don't return NULL in of_get_ocmem
	arm64: dts: msm8916: Fix reserved and rfsa nodes unit address
	arm64: dts: meson: fix broken wifi node for Khadas VIM3L
	iwlwifi: mvm: set enabled in the PPAG command properly
	ARM: s3c: fix fiq for clang IAS
	optee: simplify i2c access
	staging: wfx: fix possible panic with re-queued frames
	ARM: at91: use proper asm syntax in pm_suspend
	ath10k: Fix suspicious RCU usage warning in ath10k_wmi_tlv_parse_peer_stats_info()
	ath10k: Fix lockdep assertion warning in ath10k_sta_statistics
	ath11k: fix a locking bug in ath11k_mac_op_start()
	soc: aspeed: snoop: Add clock control logic
	iwlwifi: mvm: fix the type we use in the PPAG table validity checks
	iwlwifi: mvm: store PPAG enabled/disabled flag properly
	iwlwifi: mvm: send stored PPAG command instead of local
	iwlwifi: mvm: assign SAR table revision to the command later
	iwlwifi: mvm: don't check if CSA event is running before removing
	bpf_lru_list: Read double-checked variable once without lock
	iwlwifi: pnvm: set the PNVM again if it was already loaded
	iwlwifi: pnvm: increment the pointer before checking the TLV
	ath9k: fix data bus crash when setting nf_override via debugfs
	selftests/bpf: Convert test_xdp_redirect.sh to bash
	ibmvnic: Set to CLOSED state even on error
	bnxt_en: reverse order of TX disable and carrier off
	bnxt_en: Fix devlink info's stored fw.psid version format.
	xen/netback: fix spurious event detection for common event case
	dpaa2-eth: fix memory leak in XDP_REDIRECT
	net: phy: consider that suspend2ram may cut off PHY power
	net/mlx5e: Don't change interrupt moderation params when DIM is enabled
	net/mlx5e: Change interrupt moderation channel params also when channels are closed
	net/mlx5: Fix health error state handling
	net/mlx5e: Replace synchronize_rcu with synchronize_net
	net/mlx5e: kTLS, Use refcounts to free kTLS RX priv context
	net/mlx5: Disable devlink reload for multi port slave device
	net/mlx5: Disallow RoCE on multi port slave device
	net/mlx5: Disallow RoCE on lag device
	net/mlx5: Disable devlink reload for lag devices
	net/mlx5e: CT: manage the lifetime of the ct entry object
	net/mlx5e: Check tunnel offload is required before setting SWP
	mac80211: fix potential overflow when multiplying to u32 integers
	libbpf: Ignore non function pointer member in struct_ops
	bpf: Fix an unitialized value in bpf_iter
	bpf, devmap: Use GFP_KERNEL for xdp bulk queue allocation
	bpf: Fix bpf_fib_lookup helper MTU check for SKB ctx
	selftests: mptcp: fix ACKRX debug message
	tcp: fix SO_RCVLOWAT related hangs under mem pressure
	net: axienet: Handle deferred probe on clock properly
	cxgb4/chtls/cxgbit: Keeping the max ofld immediate data size same in cxgb4 and ulds
	b43: N-PHY: Fix the update of coef for the PHY revision >= 3case
	bpf: Clear subreg_def for global function return values
	ibmvnic: add memory barrier to protect long term buffer
	ibmvnic: skip send_request_unmap for timeout reset
	net: dsa: felix: perform teardown in reverse order of setup
	net: dsa: felix: don't deinitialize unused ports
	net: phy: mscc: adding LCPLL reset to VSC8514
	net: amd-xgbe: Reset the PHY rx data path when mailbox command timeout
	net: amd-xgbe: Fix NETDEV WATCHDOG transmit queue timeout warning
	net: amd-xgbe: Reset link when the link never comes back
	net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP
	net: mvneta: Remove per-cpu queue mapping for Armada 3700
	net: enetc: fix destroyed phylink dereference during unbind
	tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
	tty: implement read_iter
	fbdev: aty: SPARC64 requires FB_ATY_CT
	drm/gma500: Fix error return code in psb_driver_load()
	gma500: clean up error handling in init
	drm/fb-helper: Add missed unlocks in setcmap_legacy()
	drm/panel: mantix: Tweak init sequence
	drm/vc4: hdmi: Take into account the clock doubling flag in atomic_check
	crypto: sun4i-ss - linearize buffers content must be kept
	crypto: sun4i-ss - fix kmap usage
	crypto: arm64/aes-ce - really hide slower algos when faster ones are enabled
	hwrng: ingenic - Fix a resource leak in an error handling path
	media: allegro: Fix use after free on error
	kcsan: Rewrite kcsan_prandom_u32_max() without prandom_u32_state()
	drm: rcar-du: Fix PM reference leak in rcar_cmm_enable()
	drm: rcar-du: Fix crash when using LVDS1 clock for CRTC
	drm: rcar-du: Fix the return check of of_parse_phandle and of_find_device_by_node
	drm/amdgpu: Fix macro name _AMDGPU_TRACE_H_ in preprocessor if condition
	MIPS: c-r4k: Fix section mismatch for loongson2_sc_init
	MIPS: lantiq: Explicitly compare LTQ_EBU_PCC_ISTAT against 0
	drm/virtio: make sure context is created in gem open
	drm/fourcc: fix Amlogic format modifier masks
	media: ipu3-cio2: Build only for x86
	media: i2c: ov5670: Fix PIXEL_RATE minimum value
	media: imx: Unregister csc/scaler only if registered
	media: imx: Fix csc/scaler unregister
	media: mtk-vcodec: fix error return code in vdec_vp9_decode()
	media: camss: missing error code in msm_video_register()
	media: vsp1: Fix an error handling path in the probe function
	media: em28xx: Fix use-after-free in em28xx_alloc_urbs
	media: media/pci: Fix memleak in empress_init
	media: tm6000: Fix memleak in tm6000_start_stream
	media: aspeed: fix error return code in aspeed_video_setup_video()
	ASoC: cs42l56: fix up error handling in probe
	ASoC: qcom: qdsp6: Move frontend AIFs to q6asm-dai
	evm: Fix memleak in init_desc
	crypto: bcm - Rename struct device_private to bcm_device_private
	sched/fair: Avoid stale CPU util_est value for schedutil in task dequeue
	drm/sun4i: tcon: fix inverted DCLK polarity
	media: imx7: csi: Fix regression for parallel cameras on i.MX6UL
	media: imx7: csi: Fix pad link validation
	media: ti-vpe: cal: fix write to unallocated memory
	MIPS: properly stop .eh_frame generation
	MIPS: Compare __SYNC_loongson3_war against 0
	drm/tegra: Fix reference leak when pm_runtime_get_sync() fails
	drm/amdgpu: toggle on DF Cstate after finishing xgmi injection
	bsg: free the request before return error code
	macintosh/adb-iop: Use big-endian autopoll mask
	drm/amd/display: Fix 10/12 bpc setup in DCE output bit depth reduction.
	drm/amd/display: Fix HDMI deep color output for DCE 6-11.
	media: software_node: Fix refcounts in software_node_get_next_child()
	media: lmedm04: Fix misuse of comma
	media: vidtv: psi: fix missing crc for PMT
	media: atomisp: Fix a buffer overflow in debug code
	media: qm1d1c0042: fix error return code in qm1d1c0042_init()
	media: cx25821: Fix a bug when reallocating some dma memory
	media: mtk-vcodec: fix argument used when DEBUG is defined
	media: pxa_camera: declare variable when DEBUG is defined
	media: uvcvideo: Accept invalid bFormatIndex and bFrameIndex values
	sched/eas: Don't update misfit status if the task is pinned
	f2fs: compress: fix potential deadlock
	ASoC: qcom: lpass-cpu: Remove bit clock state check
	ASoC: SOF: Intel: hda: cancel D0i3 work during runtime suspend
	perf/arm-cmn: Fix PMU instance naming
	perf/arm-cmn: Move IRQs when migrating context
	mtd: parser: imagetag: fix error codes in bcm963xx_parse_imagetag_partitions()
	crypto: talitos - Work around SEC6 ERRATA (AES-CTR mode data size error)
	crypto: talitos - Fix ctr(aes) on SEC1
	drm/nouveau: bail out of nouveau_channel_new if channel init fails
	mm: proc: Invalidate TLB after clearing soft-dirty page state
	ata: ahci_brcm: Add back regulators management
	ASoC: cpcap: fix microphone timeslot mask
	ASoC: codecs: add missing max_register in regmap config
	mtd: parsers: afs: Fix freeing the part name memory in failure
	f2fs: fix to avoid inconsistent quota data
	drm/amdgpu: Prevent shift wrapping in amdgpu_read_mask()
	f2fs: fix a wrong condition in __submit_bio
	ASoC: qcom: Fix typo error in HDMI regmap config callbacks
	KVM: nSVM: Don't strip host's C-bit from guest's CR3 when reading PDPTRs
	drm/mediatek: Check if fb is null
	Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()
	ASoC: Intel: sof_sdw: add missing TGL_HDMI quirk for Dell SKU 0A5E
	ASoC: Intel: sof_sdw: add missing TGL_HDMI quirk for Dell SKU 0A3E
	locking/lockdep: Avoid unmatched unlock
	ASoC: qcom: lpass: Fix i2s ctl register bit map
	ASoC: rt5682: Fix panic in rt5682_jack_detect_handler happening during system shutdown
	ASoC: SOF: debug: Fix a potential issue on string buffer termination
	btrfs: clarify error returns values in __load_free_space_cache
	btrfs: fix double accounting of ordered extent for subpage case in btrfs_invalidapge
	KVM: x86: Restore all 64 bits of DR6 and DR7 during RSM on x86-64
	s390/zcrypt: return EIO when msg retry limit reached
	drm/vc4: hdmi: Move hdmi reset to bind
	drm/vc4: hdmi: Fix register offset with longer CEC messages
	drm/vc4: hdmi: Fix up CEC registers
	drm/vc4: hdmi: Restore cec physical address on reconnect
	drm/vc4: hdmi: Compute the CEC clock divider from the clock rate
	drm/vc4: hdmi: Update the CEC clock divider on HSM rate change
	drm/lima: fix reference leak in lima_pm_busy
	drm/dp_mst: Don't cache EDIDs for physical ports
	hwrng: timeriomem - Fix cooldown period calculation
	crypto: ecdh_helper - Ensure 'len >= secret.len' in decode_key()
	io_uring: fix possible deadlock in io_uring_poll
	nvmet-tcp: fix receive data digest calculation for multiple h2cdata PDUs
	nvmet-tcp: fix potential race of tcp socket closing accept_work
	nvme-multipath: set nr_zones for zoned namespaces
	nvmet: remove extra variable in identify ns
	nvmet: set status to 0 in case for invalid nsid
	ASoC: SOF: sof-pci-dev: add missing Up-Extreme quirk
	ima: Free IMA measurement buffer on error
	ima: Free IMA measurement buffer after kexec syscall
	ASoC: simple-card-utils: Fix device module clock
	fs/jfs: fix potential integer overflow on shift of a int
	jffs2: fix use after free in jffs2_sum_write_data()
	ubifs: Fix memleak in ubifs_init_authentication
	ubifs: replay: Fix high stack usage, again
	ubifs: Fix error return code in alloc_wbufs()
	irqchip/imx: IMX_INTMUX should not default to y, unconditionally
	smp: Process pending softirqs in flush_smp_call_function_from_idle()
	drm/amdgpu/display: remove hdcp_srm sysfs on device removal
	capabilities: Don't allow writing ambiguous v3 file capabilities
	HSI: Fix PM usage counter unbalance in ssi_hw_init
	power: supply: cpcap: Add missing IRQF_ONESHOT to fix regression
	clk: meson: clk-pll: fix initializing the old rate (fallback) for a PLL
	clk: meson: clk-pll: make "ret" a signed integer
	clk: meson: clk-pll: propagate the error from meson_clk_pll_set_rate()
	selftests/powerpc: Make the test check in eeh-basic.sh posix compliant
	regulator: qcom-rpmh-regulator: add pm8009-1 chip revision
	arm64: dts: qcom: qrb5165-rb5: fix pm8009 regulators
	quota: Fix memory leak when handling corrupted quota file
	i2c: iproc: handle only slave interrupts which are enabled
	i2c: iproc: update slave isr mask (ISR_MASK_SLAVE)
	i2c: iproc: handle master read request
	spi: cadence-quadspi: Abort read if dummy cycles required are too many
	clk: sunxi-ng: h6: Fix CEC clock
	clk: renesas: r8a779a0: Remove non-existent S2 clock
	clk: renesas: r8a779a0: Fix parent of CBFUSA clock
	HID: core: detect and skip invalid inputs to snto32()
	RDMA/siw: Fix handling of zero-sized Read and Receive Queues.
	dmaengine: fsldma: Fix a resource leak in the remove function
	dmaengine: fsldma: Fix a resource leak in an error handling path of the probe function
	dmaengine: owl-dma: Fix a resource leak in the remove function
	dmaengine: hsu: disable spurious interrupt
	mfd: bd9571mwv: Use devm_mfd_add_devices()
	power: supply: cpcap-charger: Fix missing power_supply_put()
	power: supply: cpcap-battery: Fix missing power_supply_put()
	power: supply: cpcap-charger: Fix power_supply_put on null battery pointer
	fdt: Properly handle "no-map" field in the memory region
	of/fdt: Make sure no-map does not remove already reserved regions
	RDMA/rtrs: Extend ibtrs_cq_qp_create
	RDMA/rtrs-srv: Release lock before call into close_sess
	RDMA/rtrs-srv: Use sysfs_remove_file_self for disconnect
	RDMA/rtrs-clt: Set mininum limit when create QP
	RDMA/rtrs: Call kobject_put in the failure path
	RDMA/rtrs-srv: Fix missing wr_cqe
	RDMA/rtrs-clt: Refactor the failure cases in alloc_clt
	RDMA/rtrs-srv: Init wr_cnt as 1
	power: reset: at91-sama5d2_shdwc: fix wkupdbc mask
	rtc: s5m: select REGMAP_I2C
	dmaengine: idxd: set DMA channel to be private
	power: supply: fix sbs-charger build, needs REGMAP_I2C
	clocksource/drivers/ixp4xx: Select TIMER_OF when needed
	clocksource/drivers/mxs_timer: Add missing semicolon when DEBUG is defined
	spi: imx: Don't print error on -EPROBEDEFER
	RDMA/mlx5: Use the correct obj_id upon DEVX TIR creation
	IB/mlx5: Add mutex destroy call to cap_mask_mutex mutex
	clk: sunxi-ng: h6: Fix clock divider range on some clocks
	platform/chrome: cros_ec_proto: Use EC_HOST_EVENT_MASK not BIT
	platform/chrome: cros_ec_proto: Add LID and BATTERY to default mask
	regulator: axp20x: Fix reference cout leak
	watch_queue: Drop references to /dev/watch_queue
	certs: Fix blacklist flag type confusion
	regulator: s5m8767: Fix reference count leak
	spi: atmel: Put allocated master before return
	regulator: s5m8767: Drop regulators OF node reference
	power: supply: axp20x_usb_power: Init work before enabling IRQs
	power: supply: smb347-charger: Fix interrupt usage if interrupt is unavailable
	regulator: core: Avoid debugfs: Directory ... already present! error
	isofs: release buffer head before return
	watchdog: intel-mid_wdt: Postpone IRQ handler registration till SCU is ready
	auxdisplay: ht16k33: Fix refresh rate handling
	objtool: Fix error handling for STD/CLD warnings
	objtool: Fix retpoline detection in asm code
	objtool: Fix ".cold" section suffix check for newer versions of GCC
	scsi: lpfc: Fix ancient double free
	iommu: Switch gather->end to the inclusive end
	IB/umad: Return EIO in case of when device disassociated
	IB/umad: Return EPOLLERR in case of when device disassociated
	KVM: PPC: Make the VMX instruction emulation routines static
	powerpc/47x: Disable 256k page size
	powerpc/time: Enable sched clock for irqtime
	mmc: owl-mmc: Fix a resource leak in an error handling path and in the remove function
	mmc: sdhci-sprd: Fix some resource leaks in the remove function
	mmc: usdhi6rol0: Fix a resource leak in the error handling path of the probe
	mmc: renesas_sdhi_internal_dmac: Fix DMA buffer alignment from 8 to 128-bytes
	ARM: 9046/1: decompressor: Do not clear SCTLR.nTLSMD for ARMv7+ cores
	i2c: qcom-geni: Store DMA mapping data in geni_i2c_dev struct
	amba: Fix resource leak for drivers without .remove
	iommu: Move iotlb_sync_map out from __iommu_map
	iommu: Properly pass gfp_t in _iommu_map() to avoid atomic sleeping
	IB/mlx5: Return appropriate error code instead of ENOMEM
	IB/cm: Avoid a loop when device has 255 ports
	tracepoint: Do not fail unregistering a probe due to memory failure
	rtc: zynqmp: depend on HAS_IOMEM
	perf tools: Fix DSO filtering when not finding a map for a sampled address
	perf vendor events arm64: Fix Ampere eMag event typo
	RDMA/rxe: Fix coding error in rxe_recv.c
	RDMA/rxe: Fix coding error in rxe_rcv_mcast_pkt
	RDMA/rxe: Correct skb on loopback path
	spi: stm32: properly handle 0 byte transfer
	mfd: altera-sysmgr: Fix physical address storing more
	mfd: wm831x-auxadc: Prevent use after free in wm831x_auxadc_read_irq()
	powerpc/pseries/dlpar: handle ibm, configure-connector delay status
	powerpc/8xx: Fix software emulation interrupt
	clk: qcom: gcc-msm8998: Fix Alpha PLL type for all GPLLs
	kunit: tool: fix unit test cleanup handling
	kselftests: dmabuf-heaps: Fix Makefile's inclusion of the kernel's usr/include dir
	RDMA/hns: Fixed wrong judgments in the goto branch
	RDMA/siw: Fix calculation of tx_valid_cpus size
	RDMA/hns: Fix type of sq_signal_bits
	RDMA/hns: Disable RQ inline by default
	clk: divider: fix initialization with parent_hw
	spi: pxa2xx: Fix the controller numbering for Wildcat Point
	powerpc/uaccess: Avoid might_fault() when user access is enabled
	powerpc/kuap: Restore AMR after replaying soft interrupts
	regulator: qcom-rpmh: fix pm8009 ldo7
	clk: aspeed: Fix APLL calculate formula from ast2600-A2
	selftests/ftrace: Update synthetic event syntax errors
	perf symbols: Use (long) for iterator for bfd symbols
	regulator: bd718x7, bd71828, Fix dvs voltage levels
	spi: dw: Avoid stack content exposure
	spi: Skip zero-length transfers in spi_transfer_one_message()
	printk: avoid prb_first_valid_seq() where possible
	perf symbols: Fix return value when loading PE DSO
	nfsd: register pernet ops last, unregister first
	svcrdma: Hold private mutex while invoking rdma_accept()
	ceph: fix flush_snap logic after putting caps
	RDMA/hns: Fixes missing error code of CMDQ
	RDMA/ucma: Fix use-after-free bug in ucma_create_uevent
	RDMA/rtrs-srv: Fix stack-out-of-bounds
	RDMA/rtrs: Only allow addition of path to an already established session
	RDMA/rtrs-srv: fix memory leak by missing kobject free
	RDMA/rtrs-srv-sysfs: fix missing put_device
	RDMA/rtrs-srv: Do not pass a valid pointer to PTR_ERR()
	Input: sur40 - fix an error code in sur40_probe()
	perf record: Fix continue profiling after draining the buffer
	perf intel-pt: Fix missing CYC processing in PSB
	perf intel-pt: Fix premature IPC
	perf intel-pt: Fix IPC with CYC threshold
	perf test: Fix unaligned access in sample parsing test
	Input: elo - fix an error code in elo_connect()
	sparc64: only select COMPAT_BINFMT_ELF if BINFMT_ELF is set
	sparc: fix led.c driver when PROC_FS is not enabled
	Input: zinitix - fix return type of zinitix_init_touch()
	ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled
	misc: eeprom_93xx46: Fix module alias to enable module autoprobe
	phy: rockchip-emmc: emmc_phy_init() always return 0
	phy: cadence-torrent: Fix error code in cdns_torrent_phy_probe()
	misc: eeprom_93xx46: Add module alias to avoid breaking support for non device tree users
	PCI: rcar: Always allocate MSI addresses in 32bit space
	soundwire: cadence: fix ACK/NAK handling
	pwm: rockchip: Enable APB clock during register access while probing
	pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()
	pwm: rockchip: Eliminate potential race condition when probing
	PCI: xilinx-cpm: Fix reference count leak on error path
	VMCI: Use set_page_dirty_lock() when unregistering guest memory
	PCI: Align checking of syscall user config accessors
	mei: hbm: call mei_set_devstate() on hbm stop response
	drm/msm: Fix MSM_INFO_GET_IOVA with carveout
	drm/msm/dsi: Correct io_start for MSM8994 (20nm PHY)
	drm/msm/mdp5: Fix wait-for-commit for cmd panels
	drm/msm: Fix race of GPU init vs timestamp power management.
	drm/msm: Fix races managing the OOB state for timestamp vs timestamps.
	drm/msm/dp: trigger unplug event in msm_dp_display_disable
	vfio/iommu_type1: Populate full dirty when detach non-pinned group
	vfio/iommu_type1: Fix some sanity checks in detach group
	vfio-pci/zdev: fix possible segmentation fault issue
	ext4: fix potential htree index checksum corruption
	phy: USB_LGM_PHY should depend on X86
	coresight: etm4x: Skip accessing TRCPDCR in save/restore
	nvmem: core: Fix a resource leak on error in nvmem_add_cells_from_of()
	nvmem: core: skip child nodes not matching binding
	soundwire: bus: use sdw_update_no_pm when initializing a device
	soundwire: bus: use sdw_write_no_pm when setting the bus scale registers
	soundwire: export sdw_write/read_no_pm functions
	soundwire: bus: fix confusion on device used by pm_runtime
	misc: fastrpc: fix incorrect usage of dma_map_sgtable
	remoteproc/mediatek: acknowledge watchdog IRQ after handled
	regmap: sdw: use _no_pm functions in regmap_read/write
	ext: EXT4_KUNIT_TESTS should depend on EXT4_FS instead of selecting it
	mailbox: sprd: correct definition of SPRD_OUTBOX_FIFO_FULL
	device-dax: Fix default return code of range_parse()
	PCI: pci-bridge-emul: Fix array overruns, improve safety
	PCI: cadence: Fix DMA range mapping early return error
	i40e: Fix flow for IPv6 next header (extension header)
	i40e: Add zero-initialization of AQ command structures
	i40e: Fix overwriting flow control settings during driver loading
	i40e: Fix addition of RX filters after enabling FW LLDP agent
	i40e: Fix VFs not created
	Take mmap lock in cacheflush syscall
	nios2: fixed broken sys_clone syscall
	i40e: Fix add TC filter for IPv6
	octeontx2-af: Fix an off by one in rvu_dbg_qsize_write()
	pwm: iqs620a: Fix overflow and optimize calculations
	vfio/type1: Use follow_pte()
	ice: report correct max number of TCs
	ice: Account for port VLAN in VF max packet size calculation
	ice: Fix state bits on LLDP mode switch
	ice: update the number of available RSS queues
	net: stmmac: fix CBS idleslope and sendslope calculation
	net/mlx4_core: Add missed mlx4_free_cmd_mailbox()
	PCI: rockchip: Make 'ep-gpios' DT property optional
	vxlan: move debug check after netdev unregister
	wireguard: device: do not generate ICMP for non-IP packets
	wireguard: kconfig: use arm chacha even with no neon
	ocfs2: fix a use after free on error
	mm: memcontrol: fix NR_ANON_THPS accounting in charge moving
	mm: memcontrol: fix slub memory accounting
	mm/memory.c: fix potential pte_unmap_unlock pte error
	mm/hugetlb: fix potential double free in hugetlb_register_node() error path
	mm/hugetlb: suppress wrong warning info when alloc gigantic page
	mm/compaction: fix misbehaviors of fast_find_migrateblock()
	r8169: fix jumbo packet handling on RTL8168e
	NFSv4: Fixes for nfs4_bitmask_adjust()
	KVM: SVM: Intercept INVPCID when it's disabled to inject #UD
	KVM: x86/mmu: Expand collapsible SPTE zap for TDP MMU to ZONE_DEVICE and HugeTLB pages
	arm64: Add missing ISB after invalidating TLB in __primary_switch
	i2c: brcmstb: Fix brcmstd_send_i2c_cmd condition
	i2c: exynos5: Preserve high speed master code
	mm,thp,shmem: make khugepaged obey tmpfs mount flags
	mm: fix memory_failure() handling of dax-namespace metadata
	mm/rmap: fix potential pte_unmap on an not mapped pte
	proc: use kvzalloc for our kernel buffer
	csky: Fix a size determination in gpr_get()
	scsi: bnx2fc: Fix Kconfig warning & CNIC build errors
	scsi: sd: sd_zbc: Don't pass GFP_NOIO to kvcalloc
	block: reopen the device in blkdev_reread_part
	ide/falconide: Fix module unload
	scsi: sd: Fix Opal support
	blk-settings: align max_sectors on "logical_block_size" boundary
	soundwire: intel: fix possible crash when no device is detected
	ACPI: property: Fix fwnode string properties matching
	ACPI: configfs: add missing check after configfs_register_default_group()
	cpufreq: ACPI: Set cpuinfo.max_freq directly if max boost is known
	HID: logitech-dj: add support for keyboard events in eQUAD step 4 Gaming
	HID: wacom: Ignore attempts to overwrite the touch_max value from HID
	Input: raydium_ts_i2c - do not send zero length
	Input: xpad - add support for PowerA Enhanced Wired Controller for Xbox Series X|S
	Input: joydev - prevent potential read overflow in ioctl
	Input: i8042 - add ASUS Zenbook Flip to noselftest list
	media: mceusb: Fix potential out-of-bounds shift
	USB: serial: option: update interface mapping for ZTE P685M
	usb: musb: Fix runtime PM race in musb_queue_resume_work
	usb: dwc3: gadget: Fix setting of DEPCFG.bInterval_m1
	usb: dwc3: gadget: Fix dep->interval for fullspeed interrupt
	USB: serial: ftdi_sio: fix FTX sub-integer prescaler
	USB: serial: pl2303: fix line-speed handling on newer chips
	USB: serial: mos7840: fix error code in mos7840_write()
	USB: serial: mos7720: fix error code in mos7720_write()
	phy: lantiq: rcu-usb2: wait after clock enable
	ALSA: fireface: fix to parse sync status register of latter protocol
	ALSA: hda: Add another CometLake-H PCI ID
	ALSA: hda/hdmi: Drop bogus check at closing a stream
	ALSA: hda/realtek: modify EAPD in the ALC886
	ALSA: hda/realtek: Quirk for HP Spectre x360 14 amp setup
	MIPS: Ingenic: Disable HPTLB for D0 XBurst CPUs too
	MIPS: Support binutils configured with --enable-mips-fix-loongson3-llsc=yes
	MIPS: VDSO: Use CLANG_FLAGS instead of filtering out '--target='
	Revert "MIPS: Octeon: Remove special handling of CONFIG_MIPS_ELF_APPENDED_DTB=y"
	Revert "bcache: Kill btree_io_wq"
	bcache: Give btree_io_wq correct semantics again
	bcache: Move journal work to new flush wq
	Revert "drm/amd/display: Update NV1x SR latency values"
	drm/amd/display: Add FPU wrappers to dcn21_validate_bandwidth()
	drm/amd/display: Remove Assert from dcn10_get_dig_frontend
	drm/amd/display: Add vupdate_no_lock interrupts for DCN2.1
	drm/amdkfd: Fix recursive lock warnings
	drm/amdgpu: Set reference clock to 100Mhz on Renoir (v2)
	drm/nouveau/kms: handle mDP connectors
	drm/modes: Switch to 64bit maths to avoid integer overflow
	drm/sched: Cancel and flush all outstanding jobs before finish.
	drm/panel: kd35t133: allow using non-continuous dsi clock
	drm/rockchip: Require the YTR modifier for AFBC
	ASoC: siu: Fix build error by a wrong const prefix
	selinux: fix inconsistency between inode_getxattr and inode_listsecurity
	erofs: initialized fields can only be observed after bit is set
	tpm_tis: Fix check_locality for correct locality acquisition
	tpm_tis: Clean up locality release
	KEYS: trusted: Fix incorrect handling of tpm_get_random()
	KEYS: trusted: Fix migratable=1 failing
	KEYS: trusted: Reserve TPM for seal and unseal operations
	btrfs: do not cleanup upper nodes in btrfs_backref_cleanup_node
	btrfs: do not warn if we can't find the reloc root when looking up backref
	btrfs: add asserts for deleting backref cache nodes
	btrfs: abort the transaction if we fail to inc ref in btrfs_copy_root
	btrfs: fix reloc root leak with 0 ref reloc roots on recovery
	btrfs: splice remaining dirty_bg's onto the transaction dirty bg list
	btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself
	btrfs: account for new extents being deleted in total_bytes_pinned
	btrfs: fix extent buffer leak on failure to copy root
	drm/i915/gt: Flush before changing register state
	drm/i915/gt: Correct surface base address for renderclear
	crypto: arm64/sha - add missing module aliases
	crypto: aesni - prevent misaligned buffers on the stack
	crypto: michael_mic - fix broken misalignment handling
	crypto: sun4i-ss - checking sg length is not sufficient
	crypto: sun4i-ss - IV register does not work on A10 and A13
	crypto: sun4i-ss - handle BigEndian for cipher
	crypto: sun4i-ss - initialize need_fallback
	soc: samsung: exynos-asv: don't defer early on not-supported SoCs
	soc: samsung: exynos-asv: handle reading revision register error
	seccomp: Add missing return in non-void function
	arm64: ptrace: Fix seccomp of traced syscall -1 (NO_SYSCALL)
	misc: rtsx: init of rts522a add OCP power off when no card is present
	drivers/misc/vmw_vmci: restrict too big queue size in qp_host_alloc_queue
	pstore: Fix typo in compression option name
	dts64: mt7622: fix slow sd card access
	arm64: dts: agilex: fix phy interface bit shift for gmac1 and gmac2
	staging/mt7621-dma: mtk-hsdma.c->hsdma-mt7621.c
	staging: gdm724x: Fix DMA from stack
	staging: rtl8188eu: Add Edimax EW-7811UN V2 to device table
	floppy: reintroduce O_NDELAY fix
	media: i2c: max9286: fix access to unallocated memory
	media: ir_toy: add another IR Droid device
	media: ipu3-cio2: Fix mbus_code processing in cio2_subdev_set_fmt()
	media: marvell-ccic: power up the device on mclk enable
	media: smipcie: fix interrupt handling and IR timeout
	x86/virt: Eat faults on VMXOFF in reboot flows
	x86/reboot: Force all cpus to exit VMX root if VMX is supported
	x86/fault: Fix AMD erratum #91 errata fixup for user code
	x86/entry: Fix instrumentation annotation
	powerpc/prom: Fix "ibm,arch-vec-5-platform-support" scan
	rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers
	rcu/nocb: Perform deferred wake up before last idle's need_resched() check
	kprobes: Fix to delay the kprobes jump optimization
	arm64: Extend workaround for erratum 1024718 to all versions of Cortex-A55
	iommu/arm-smmu-qcom: Fix mask extraction for bootloader programmed SMRs
	arm64: kexec_file: fix memory leakage in create_dtb() when fdt_open_into() fails
	arm64: uprobe: Return EOPNOTSUPP for AARCH32 instruction probing
	arm64 module: set plt* section addresses to 0x0
	arm64: spectre: Prevent lockdep splat on v4 mitigation enable path
	riscv: Disable KSAN_SANITIZE for vDSO
	watchdog: qcom: Remove incorrect usage of QCOM_WDT_ENABLE_IRQ
	watchdog: mei_wdt: request stop on unregister
	coresight: etm4x: Handle accesses to TRCSTALLCTLR
	mtd: spi-nor: sfdp: Fix last erase region marking
	mtd: spi-nor: sfdp: Fix wrong erase type bitmask for overlaid region
	mtd: spi-nor: core: Fix erase type discovery for overlaid region
	mtd: spi-nor: core: Add erase size check for erase command initialization
	mtd: spi-nor: hisi-sfc: Put child node np on error path
	fs/affs: release old buffer head on error path
	seq_file: document how per-entry resources are managed.
	x86: fix seq_file iteration for pat/memtype.c
	mm: memcontrol: fix swap undercounting in cgroup2
	mm: memcontrol: fix get_active_memcg return value
	hugetlb: fix update_and_free_page contig page struct assumption
	hugetlb: fix copy_huge_page_from_user contig page struct assumption
	mm/vmscan: restore zone_reclaim_mode ABI
	mm, compaction: make fast_isolate_freepages() stay within zone
	KVM: nSVM: fix running nested guests when npt=0
	nvmem: qcom-spmi-sdam: Fix uninitialized pdev pointer
	module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
	mmc: sdhci-esdhc-imx: fix kernel panic when remove module
	mmc: sdhci-pci-o2micro: Bug fix for SDR104 HW tuning failure
	powerpc/32: Preserve cr1 in exception prolog stack check to fix build error
	powerpc/kexec_file: fix FDT size estimation for kdump kernel
	powerpc/32s: Add missing call to kuep_lock on syscall entry
	spmi: spmi-pmic-arb: Fix hw_irq overflow
	mei: fix transfer over dma with extended header
	mei: me: emmitsburg workstation DID
	mei: me: add adler lake point S DID
	mei: me: add adler lake point LP DID
	gpio: pcf857x: Fix missing first interrupt
	mfd: gateworks-gsc: Fix interrupt type
	printk: fix deadlock when kernel panic
	exfat: fix shift-out-of-bounds in exfat_fill_super()
	zonefs: Fix file size of zones in full condition
	kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE
	thermal: cpufreq_cooling: freq_qos_update_request() returns < 0 on error
	cpufreq: qcom-hw: drop devm_xxx() calls from init/exit hooks
	cpufreq: intel_pstate: Change intel_pstate_get_hwp_max() argument
	cpufreq: intel_pstate: Get per-CPU max freq via MSR_HWP_CAPABILITIES if available
	proc: don't allow async path resolution of /proc/thread-self components
	s390/vtime: fix inline assembly clobber list
	virtio/s390: implement virtio-ccw revision 2 correctly
	um: mm: check more comprehensively for stub changes
	um: defer killing userspace on page table update failures
	irqchip/loongson-pch-msi: Use bitmap_zalloc() to allocate bitmap
	f2fs: fix out-of-repair __setattr_copy()
	f2fs: enforce the immutable flag on open files
	f2fs: flush data when enabling checkpoint back
	sparc32: fix a user-triggerable oops in clear_user()
	spi: fsl: invert spisel_boot signal on MPC8309
	spi: spi-synquacer: fix set_cs handling
	gfs2: fix glock confusion in function signal_our_withdraw
	gfs2: Don't skip dlm unlock if glock has an lvb
	gfs2: Lock imbalance on error path in gfs2_recover_one
	gfs2: Recursive gfs2_quota_hold in gfs2_iomap_end
	dm: fix deadlock when swapping to encrypted device
	dm table: fix iterate_devices based device capability checks
	dm table: fix DAX iterate_devices based device capability checks
	dm table: fix zoned iterate_devices based device capability checks
	dm writecache: fix performance degradation in ssd mode
	dm writecache: return the exact table values that were set
	dm writecache: fix writing beyond end of underlying device when shrinking
	dm era: Recover committed writeset after crash
	dm era: Update in-core bitset after committing the metadata
	dm era: Verify the data block size hasn't changed
	dm era: Fix bitset memory leaks
	dm era: Use correct value size in equality function of writeset tree
	dm era: Reinitialize bitset cache before digesting a new writeset
	dm era: only resize metadata in preresume
	drm/i915: Reject 446-480MHz HDMI clock on GLK
	kgdb: fix to kill breakpoints on initmem after boot
	ipv6: silence compilation warning for non-IPV6 builds
	net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending
	wireguard: selftests: test multiple parallel streams
	wireguard: queueing: get rid of per-peer ring buffers
	net: sched: fix police ext initialization
	net: qrtr: Fix memory leak in qrtr_tun_open
	net_sched: fix RTNL deadlock again caused by request_module()
	ARM: dts: aspeed: Add LCLK to lpc-snoop
	Linux 5.10.20

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I3fbcecd9413ce212dac68d5cc800c9457feba56a
2021-03-07 12:33:33 +01:00
Dave Hansen
54683f81c8 mm/vmscan: restore zone_reclaim_mode ABI
commit 519983645a9f2ec339cabfa0c6ef7b09be985dd0 upstream.

I went to go add a new RECLAIM_* mode for the zone_reclaim_mode sysctl.
Like a good kernel developer, I also went to go update the
documentation.  I noticed that the bits in the documentation didn't
match the bits in the #defines.

The VM never explicitly checks the RECLAIM_ZONE bit.  The bit is,
however implicitly checked when checking 'node_reclaim_mode==0'.  The
RECLAIM_ZONE #define was removed in a cleanup.  That, by itself is fine.

But, when the bit was removed (bit 0) the _other_ bit locations also got
changed.  That's not OK because the bit values are documented to mean
one specific thing.  Users surely do not expect the meaning to change
from kernel to kernel.

The end result is that if someone had a script that did:

	sysctl vm.zone_reclaim_mode=1

it would have gone from enabling node reclaim for clean unmapped pages
to writing out pages during node reclaim after the commit in question.
That's not great.

Put the bits back the way they were and add a comment so something like
this is a bit harder to do again.  Update the documentation to make it
clear that the first bit is ignored.

Link: https://lkml.kernel.org/r/20210219172555.FF0CDF23@viggo.jf.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Fixes: 648b5cf368 ("mm/vmscan: remove unused RECLAIM_OFF/RECLAIM_ZONE")
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Daniel Wagner <dwagner@suse.de>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.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>
2021-03-04 11:38:38 +01:00
Suren Baghdasaryan
aa8f690d71 ANDROID: vmscan: Fix sparse warnings for kswapd_threads
Fix the following warning by declaring kswapd_threads as static:
mm/vmscan.c:175:5: sparse: symbol 'kswapd_threads' was not declared.

Fixes: 0d61a651e4 ("ANDROID: vmscan: Support multiple kswapd threads per node")
Bug: 171351667
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I6ccb1e0e0f597fda27ed6893d254a77341139084
2021-02-22 18:13:47 -08:00
Charan Teja Reddy
0d61a651e4 ANDROID: vmscan: Support multiple kswapd threads per node
Page replacement is handled in the Linux Kernel in one of two ways:

1) Asynchronously via kswapd
2) Synchronously, via direct reclaim

At page allocation time the allocating task is immediately given a page
from the zone free list allowing it to go right back to work doing
whatever it was doing; Probably directly or indirectly executing business
logic.

Just prior to satisfying the allocation, free pages is checked to see if
it has reached the zone low watermark and if so, kswapd is awakened.
Kswapd will start scanning pages looking for inactive pages to evict to
make room for new page allocations. The work of kswapd allows tasks to
continue allocating memory from their respective zone free list without
incurring any delay.

When the demand for free pages exceeds the rate that kswapd tasks can
supply them, page allocation works differently. Once the allocating task
finds that the number of free pages is at or below the zone min watermark,
the task will no longer pull pages from the free list. Instead, the task
will run the same CPU-bound routines as kswapd to satisfy its own
allocation by scanning and evicting pages. This is called a direct reclaim.

The time spent performing a direct reclaim can be substantial, often
taking tens to hundreds of milliseconds for small order0 allocations to
half a second or more for order9 huge-page allocations. In fact, kswapd is
not actually required on a linux system. It exists for the sole purpose of
optimizing performance by preventing direct reclaims.

When memory shortfall is sufficient to trigger direct reclaims, they can
occur in any task that is running on the system. A single aggressive
memory allocating task can set the stage for collateral damage to occur in
small tasks that rarely allocate additional memory. Consider the impact of
injecting an additional 100ms of latency when nscd allocates memory to
facilitate caching of a DNS query.

The presence of direct reclaims 10 years ago was a fairly reliable
indicator that too much was being asked of a Linux system. Kswapd was
likely wasting time scanning pages that were ineligible for eviction.
Adding RAM or reducing the working set size would usually make the problem
go away. Since then hardware has evolved to bring a new struggle for
kswapd. Storage speeds have increased by orders of magnitude while CPU
clock speeds stayed the same or even slowed down in exchange for more
cores per package. This presents a throughput problem for a single
threaded kswapd that will get worse with each generation of new hardware.

Test Details

NOTE: The tests below were run with shadow entries disabled. See the
associated patch and cover letter for details

The tests below were designed with the assumption that a kswapd bottleneck
is best demonstrated using filesystem reads. This way, the inactive list
will be full of clean pages, simplifying the analysis and allowing kswapd
to achieve the highest possible steal rate. Maximum steal rates for kswapd
are likely to be the same or lower for any other mix of page types on the
system.

Tests were run on a 2U Oracle X7-2L with 52 Intel Xeon Skylake 2GHz cores,
756GB of RAM and 8 x 3.6 TB NVMe Solid State Disk drives. Each drive has
an XFS file system mounted separately as /d0 through /d7. SSD drives
require multiple concurrent streams to show their potential, so I created
eleven 250GB zero-filled files on each drive so that I could test with
parallel reads.

The test script runs in multiple stages. At each stage, the number of dd
tasks run concurrently is increased by 2. I did not include all of the
test output for brevity.

During each stage dd tasks are launched to read from each drive in a round
robin fashion until the specified number of tasks for the stage has been
reached. Then iostat, vmstat and top are started in the background with 10
second intervals. After five minutes, all of the dd tasks are killed and
the iostat, vmstat and top output is parsed in order to report the
following:

CPU consumption
- sy - aggregate kernel mode CPU consumption from vmstat output. The value
       doesn't tend to fluctuate much so I just grab the highest value.
       Each sample is averaged over 10 seconds
- dd_cpu - for all of the dd tasks averaged across the top samples since
           there is a lot of variation.

Throughput
- in Kbytes
- Command is iostat -x -d 10 -g total

This first test performs reads using O_DIRECT in order to show the maximum
throughput that can be obtained using these drives. It also demonstrates
how rapidly throughput scales as the number of dd tasks are increased.

The dd command for this test looks like this:

Command Used: dd iflag=direct if=/d${i}/$n of=/dev/null bs=4M

Test #1: Direct IO
dd sy dd_cpu throughput
6  0  2.33   14726026.40
10 1  2.95   19954974.80
16 1  2.63   24419689.30
22 1  2.63   25430303.20
28 1  2.91   26026513.20
34 1  2.53   26178618.00
40 1  2.18   26239229.20
46 1  1.91   26250550.40
52 1  1.69   26251845.60
58 1  1.54   26253205.60
64 1  1.43   26253780.80
70 1  1.31   26254154.80
76 1  1.21   26253660.80
82 1  1.12   26254214.80
88 1  1.07   26253770.00
90 1  1.04   26252406.40

Throughput was close to peak with only 22 dd tasks. Very little system CPU
was consumed as expected as the drives DMA directly into the user address
space when using direct IO.

In this next test, the iflag=direct option is removed and we only run the
test until the pgscan_kswapd from /proc/vmstat starts to increment. At
that point metrics are parsed and reported and the pagecache contents are
dropped prior to the next test. Lather, rinse, repeat.

Test #2: standard file system IO, no page replacement
dd sy dd_cpu throughput
6  2  28.78  5134316.40
10 3  31.40  8051218.40
16 5  34.73  11438106.80
22 7  33.65  14140596.40
28 8  31.24  16393455.20
34 10 29.88  18219463.60
40 11 28.33  19644159.60
46 11 25.05  20802497.60
52 13 26.92  22092370.00
58 13 23.29  22884881.20
64 14 23.12  23452248.80
70 15 22.40  23916468.00
76 16 22.06  24328737.20
82 17 20.97  24718693.20
88 16 18.57  25149404.40
90 16 18.31  25245565.60

Each read has to pause after the buffer in kernel space is populated while
those pages are added to the pagecache and copied into the user address
space. For this reason, more parallel streams are required to achieve peak
throughput. The copy operation consumes substantially more CPU than direct
IO as expected.

The next test measures throughput after kswapd starts running. This is the
same test only we wait for kswapd to wake up before we start collecting
metrics. The script actually keeps track of a few things that were not
mentioned earlier. It tracks direct reclaims and page scans by watching
the metrics in /proc/vmstat. CPU consumption for kswapd is tracked the
same way it is tracked for dd.

Since the test is 100% reads, you can assume that the page steal rate for
kswapd and direct reclaims is almost identical to the scan rate.

Test #3: 1 kswapd thread per node
dd sy dd_cpu kswapd0 kswapd1 throughput  dr    pgscan_kswapd pgscan_direct
10 4  26.07  28.56   27.03   7355924.40  0     459316976     0
16 7  34.94  69.33   69.66   10867895.20 0     872661643     0
22 10 36.03  93.99   99.33   13130613.60 489   1037654473    11268334
28 10 30.34  95.90   98.60   14601509.60 671   1182591373    15429142
34 14 34.77  97.50   99.23   16468012.00 10850 1069005644    249839515
40 17 36.32  91.49   97.11   17335987.60 18903 975417728     434467710
46 19 38.40  90.54   91.61   17705394.40 25369 855737040     582427973
52 22 40.88  83.97   83.70   17607680.40 31250 709532935     724282458
58 25 40.89  82.19   80.14   17976905.60 35060 657796473     804117540
64 28 41.77  73.49   75.20   18001910.00 39073 561813658     895289337
70 33 45.51  63.78   64.39   17061897.20 44523 379465571     1020726436
76 36 46.95  57.96   60.32   16964459.60 47717 291299464     1093172384
82 39 47.16  55.43   56.16   16949956.00 49479 247071062     1134163008
88 42 47.41  53.75   47.62   16930911.20 51521 195449924     1180442208
90 43 47.18  51.40   50.59   16864428.00 51618 190758156     1183203901

In the previous test where kswapd was not involved, the system-wide kernel
mode CPU consumption with 90 dd tasks was 16%. In this test CPU consumption
with 90 tasks is at 43%. With 52 cores, and two kswapd tasks (one per NUMA
node), kswapd can only be responsible for a little over 4% of the increase.
The rest is likely caused by 51,618 direct reclaims that scanned 1.2
billion pages over the five minute time period of the test.

Same test, more kswapd tasks:

Test #4: 4 kswapd threads per node
dd sy dd_cpu kswapd0 kswapd1 throughput  dr    pgscan_kswapd pgscan_direct
10 5  27.09  16.65   14.17   7842605.60  0     459105291     0
16 10 37.12  26.02   24.85   11352920.40 15    920527796     358515
22 11 36.94  37.13   35.82   13771869.60 0     1132169011     0
28 13 35.23  48.43   46.86   16089746.00 0     1312902070     0
34 15 33.37  53.02   55.69   18314856.40 0     1476169080     0
40 19 35.90  69.60   64.41   19836126.80 0     1629999149     0
46 22 36.82  88.55   57.20   20740216.40 0     1708478106     0
52 24 34.38  93.76   68.34   21758352.00 0     1794055559     0
58 24 30.51  79.20   82.33   22735594.00 0     1872794397     0
64 26 30.21  97.12   76.73   23302203.60 176   1916593721     4206821
70 33 32.92  92.91   92.87   23776588.00 3575  1817685086     85574159
76 37 31.62  91.20   89.83   24308196.80 4752  1812262569     113981763
82 29 25.53  93.23   92.33   24802791.20 306   2032093122     7350704
88 43 37.12  76.18   77.01   25145694.40 20310 1253204719     487048202
90 42 38.56  73.90   74.57   22516787.60 22774 1193637495     545463615

By increasing the number of kswapd threads, throughput increased by ~50%
while kernel mode CPU utilization decreased or stayed the same, likely due
to a decrease in the number of parallel tasks at any given time doing page
replacement.

Signed-off-by: Buddy Lumpkin <buddy.lumpkin@oracle.com>
Bug: 171351667
Link: https://lore.kernel.org/lkml/1522661062-39745-1-git-send-email-buddy.lumpkin@oracle.com
[charante@codeaurora.org]: Changes made to select number of kswapds through uapi
Change-Id: I8425cab7f40cbeaf65af0ea118c1a9ac7da0930e
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
2021-02-22 19:47:44 +00:00
Linus Torvalds
72c5ce8942 mm: don't put pinned pages into the swap cache
[ Upstream commit feb889fb40fafc6933339cf1cca8f770126819fb ]

So technically there is nothing wrong with adding a pinned page to the
swap cache, but the pinning obviously means that the page can't actually
be free'd right now anyway, so it's a bit pointless.

However, the real problem is not with it being a bit pointless: the real
issue is that after we've added it to the swap cache, we'll try to unmap
the page.  That will succeed, because the code in mm/rmap.c doesn't know
or care about pinned pages.

Even the unmapping isn't fatal per se, since the page will stay around
in memory due to the pinning, and we do hold the connection to it using
the swap cache.  But when we then touch it next and take a page fault,
the logic in do_swap_page() will map it back into the process as a
possibly read-only page, and we'll then break the page association on
the next COW fault.

Honestly, this issue could have been fixed in any of those other places:
(a) we could refuse to unmap a pinned page (which makes conceptual
sense), or (b) we could make sure to re-map a pinned page writably in
do_swap_page(), or (c) we could just make do_wp_page() not COW the
pinned page (which was what we historically did before that "mm:
do_wp_page() simplification" commit).

But while all of them are equally valid models for breaking this chain,
not putting pinned pages into the swap cache in the first place is the
simplest one by far.

It's also the safest one: the reason why do_wp_page() was changed in the
first place was that getting the "can I re-use this page" wrong is so
fraught with errors.  If you do it wrong, you end up with an incorrectly
shared page.

As a result, using "page_maybe_dma_pinned()" in either do_wp_page() or
do_swap_page() would be a serious bug since it is only a (very good)
heuristic.  Re-using the page requires a hard black-and-white rule with
no room for ambiguity.

In contrast, saying "this page is very likely dma pinned, so let's not
add it to the swap cache and try to unmap it" is an obviously safe thing
to do, and if the heuristic might very rarely be a false positive, no
harm is done.

Fixes: 09854ba94c ("mm: do_wp_page() simplification")
Reported-and-tested-by: Martin Raiber <martin@urbackup.org>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19 18:27:29 +01:00
Shakeel Butt
dd156e3fca mm/rmap: always do TTU_IGNORE_ACCESS
[ Upstream commit 013339df116c2ee0d796dd8bfb8f293a2030c063 ]

Since commit 369ea8242c ("mm/rmap: update to new mmu_notifier semantic
v2"), the code to check the secondary MMU's page table access bit is
broken for !(TTU_IGNORE_ACCESS) because the page is unmapped from the
secondary MMU's page table before the check.  More specifically for those
secondary MMUs which unmap the memory in
mmu_notifier_invalidate_range_start() like kvm.

However memory reclaim is the only user of !(TTU_IGNORE_ACCESS) or the
absence of TTU_IGNORE_ACCESS and it explicitly performs the page table
access check before trying to unmap the page.  So, at worst the reclaim
will miss accesses in a very short window if we remove page table access
check in unmapping code.

There is an unintented consequence of !(TTU_IGNORE_ACCESS) for the memcg
reclaim.  From memcg reclaim the page_referenced() only account the
accesses from the processes which are in the same memcg of the target page
but the unmapping code is considering accesses from all the processes, so,
decreasing the effectiveness of memcg reclaim.

The simplest solution is to always assume TTU_IGNORE_ACCESS in unmapping
code.

Link: https://lkml.kernel.org/r/20201104231928.1494083-1-shakeelb@google.com
Fixes: 369ea8242c ("mm/rmap: update to new mmu_notifier semantic v2")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:55 +01:00
Nicholas Piggin
2da9f6305f mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit
Previously the negated unsigned long would be cast back to signed long
which would have the correct negative value.  After commit 730ec8c01a
("mm/vmscan.c: change prototype for shrink_page_list"), the large
unsigned int converts to a large positive signed long.

Symptoms include CMA allocations hanging forever holding the cma_mutex
due to alloc_contig_range->...->isolate_migratepages_block waiting
forever in "while (unlikely(too_many_isolated(pgdat)))".

[akpm@linux-foundation.org: fix -stat.nr_lazyfree_fail as well, per Michal]

Fixes: 730ec8c01a ("mm/vmscan.c: change prototype for shrink_page_list")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vaneet Narang <v.narang@samsung.com>
Cc: Maninder Singh <maninder1.s@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201029032320.1448441-1-npiggin@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Yu Zhao
ed0173733d mm: use self-explanatory macros rather than "2"
Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Link: http://lkml.kernel.org/r/20200831175042.3527153-2-yuzhao@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:19 -07:00
Matthew Wilcox (Oracle)
3efe62e466 mm/vmscan: allow arbitrary sized pages to be paged out
Remove the assumption that a compound page has HPAGE_PMD_NR pins from the
page cache.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Link: https://lkml.kernel.org/r/20200908195539.25896-12-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:15 -07:00
Hui Su
01c4776ba0 mm/vmscan: fix comments for isolate_lru_page()
fix comments for isolate_lru_page():
s/fundamentnal/fundamental

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200927173923.GA8058@rlk
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:34 -07:00
Chunxin Zang
069c411de4 mm/vmscan: fix infinite loop in drop_slab_node
We have observed that drop_caches can take a considerable amount of
time (<put data here>).  Especially when there are many memcgs involved
because they are adding an additional overhead.

It is quite unfortunate that the operation cannot be interrupted by a
signal currently.  Add a check for fatal signals into the main loop so
that userspace can control early bailout.

There are two reasons:

1. We have too many memcgs, even though one object freed in one memcg,
   the sum of object is bigger than 10.

2. We spend a lot of time in traverse memcg once.  So, the memcg who
   traversed at the first have been freed many objects.  Traverse memcg
   next time, the freed count bigger than 10 again.

We can get the following info through 'ps':

  root:~# ps -aux | grep drop
  root  357956 ... R    Aug25 21119854:55 echo 3 > /proc/sys/vm/drop_caches
  root 1771385 ... R    Aug16 21146421:17 echo 3 > /proc/sys/vm/drop_caches
  root 1986319 ... R    18:56 117:27 echo 3 > /proc/sys/vm/drop_caches
  root 2002148 ... R    Aug24 5720:39 echo 3 > /proc/sys/vm/drop_caches
  root 2564666 ... R    18:59 113:58 echo 3 > /proc/sys/vm/drop_caches
  root 2639347 ... R    Sep03 2383:39 echo 3 > /proc/sys/vm/drop_caches
  root 3904747 ... R    03:35 993:31 echo 3 > /proc/sys/vm/drop_caches
  root 4016780 ... R    Aug21 7882:18 echo 3 > /proc/sys/vm/drop_caches

Use bpftrace follow 'freed' value in drop_slab_node:

  root:~# bpftrace -e 'kprobe:drop_slab_node+70 {@ret=hist(reg("bp")); }'
  Attaching 1 probe...
  ^B^C

  @ret:
  [64, 128)        1 |                                                    |
  [128, 256)      28 |                                                    |
  [256, 512)     107 |@                                                   |
  [512, 1K)      298 |@@@                                                 |
  [1K, 2K)       613 |@@@@@@@                                             |
  [2K, 4K)      4435 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
  [4K, 8K)       442 |@@@@@                                               |
  [8K, 16K)      299 |@@@                                                 |
  [16K, 32K)     100 |@                                                   |
  [32K, 64K)     139 |@                                                   |
  [64K, 128K)     56 |                                                    |
  [128K, 256K)    26 |                                                    |
  [256K, 512K)     2 |                                                    |

In the while loop, we can check whether the TASK_KILLABLE signal is set,
if so, we should break the loop.

Signed-off-by: Chunxin Zang <zangchunxin@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20200909152047.27905-1-zangchunxin@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:34 -07:00
Hugh Dickins
8d8869ca5d mm: fix check_move_unevictable_pages() on THP
check_move_unevictable_pages() is used in making unevictable shmem pages
evictable: by shmem_unlock_mapping(), drm_gem_check_release_pagevec() and
i915/gem check_release_pagevec().  Those may pass down subpages of a huge
page, when /sys/kernel/mm/transparent_hugepage/shmem_enabled is "force".

That does not crash or warn at present, but the accounting of vmstats
unevictable_pgs_scanned and unevictable_pgs_rescued is inconsistent:
scanned being incremented on each subpage, rescued only on the head (since
tails already appear evictable once the head has been updated).

5.8 commit 5d91f31faf ("mm: swap: fix vmstats for huge page") has
established that vm_events in general (and unevictable_pgs_rescued in
particular) should count every subpage: so follow that precedent here.

Do this in such a way that if mem_cgroup_page_lruvec() is made stricter
(to check page->mem_cgroup is always set), no problem: skip the tails
before calling it, and add thp_nr_pages() to vmstats on the head.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008301405000.5954@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-19 13:13:38 -07:00
Xunlei Pang
e3336cab25 mm: memcg: fix memcg reclaim soft lockup
We've met softlockup with "CONFIG_PREEMPT_NONE=y", when the target memcg
doesn't have any reclaimable memory.

It can be easily reproduced as below:

  watchdog: BUG: soft lockup - CPU#0 stuck for 111s![memcg_test:2204]
  CPU: 0 PID: 2204 Comm: memcg_test Not tainted 5.9.0-rc2+ #12
  Call Trace:
    shrink_lruvec+0x49f/0x640
    shrink_node+0x2a6/0x6f0
    do_try_to_free_pages+0xe9/0x3e0
    try_to_free_mem_cgroup_pages+0xef/0x1f0
    try_charge+0x2c1/0x750
    mem_cgroup_charge+0xd7/0x240
    __add_to_page_cache_locked+0x2fd/0x370
    add_to_page_cache_lru+0x4a/0xc0
    pagecache_get_page+0x10b/0x2f0
    filemap_fault+0x661/0xad0
    ext4_filemap_fault+0x2c/0x40
    __do_fault+0x4d/0xf9
    handle_mm_fault+0x1080/0x1790

It only happens on our 1-vcpu instances, because there's no chance for
oom reaper to run to reclaim the to-be-killed process.

Add a cond_resched() at the upper shrink_node_memcgs() to solve this
issue, this will mean that we will get a scheduling point for each memcg
in the reclaimed hierarchy without any dependency on the reclaimable
memory in that memcg thus making it more predictable.

Suggested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Xunlei Pang <xlpang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: http://lkml.kernel.org/r/1598495549-67324-1-git-send-email-xlpang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-05 12:14:29 -07:00
Matthew Wilcox (Oracle)
6c357848b4 mm: replace hpage_nr_pages with thp_nr_pages
The thp prefix is more frequently used than hpage and we should be
consistent between the various functions.

[akpm@linux-foundation.org: fix mm/migrate.c]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-6-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14 19:56:56 -07:00
Randy Dunlap
1eba09c15d mm/vmscan.c: delete or fix duplicated words
Drop the repeated word "marked".
Change "time time" to "same time".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200801173822.14973-14-rdunlap@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:58 -07:00
Joonsoo Kim
4002570c5c mm/vmscan: restore active/inactive ratio for anonymous LRU
Now that workingset detection is implemented for anonymous LRU, we don't
need large inactive list to allow detecting frequently accessed pages
before they are reclaimed, anymore.  This effectively reverts the
temporary measure put in by commit "mm/vmscan: make active/inactive ratio
as 1:1 for anon lru".

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-7-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:56 -07:00
Joonsoo Kim
aae466b005 mm/swap: implement workingset detection for anonymous LRU
This patch implements workingset detection for anonymous LRU.  All the
infrastructure is implemented by the previous patches so this patch just
activates the workingset detection by installing/retrieving the shadow
entry and adding refault calculation.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:56 -07:00
Joonsoo Kim
3852f6768e mm/swapcache: support to handle the shadow entries
Workingset detection for anonymous page will be implemented in the
following patch and it requires to store the shadow entries into the
swapcache.  This patch implements an infrastructure to store the shadow
entry in the swapcache.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1595490560-15117-5-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:55 -07:00
Joonsoo Kim
170b04b7ae mm/workingset: prepare the workingset detection infrastructure for anon LRU
To prepare the workingset detection for anon LRU, this patch splits
workingset event counters for refault, activate and restore into anon and
file variants, as well as the refaults counter in struct lruvec.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-4-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:55 -07:00
Joonsoo Kim
b518154e59 mm/vmscan: protect the workingset on anonymous LRU
In current implementation, newly created or swap-in anonymous page is
started on active list.  Growing active list results in rebalancing
active/inactive list so old pages on active list are demoted to inactive
list.  Hence, the page on active list isn't protected at all.

Following is an example of this situation.

Assume that 50 hot pages on active list.  Numbers denote the number of
pages on active/inactive list (active | inactive).

1. 50 hot pages on active list
50(h) | 0

2. workload: 50 newly created (used-once) pages
50(uo) | 50(h)

3. workload: another 50 newly created (used-once) pages
50(uo) | 50(uo), swap-out 50(h)

This patch tries to fix this issue.  Like as file LRU, newly created or
swap-in anonymous pages will be inserted to the inactive list.  They are
promoted to active list if enough reference happens.  This simple
modification changes the above example as following.

1. 50 hot pages on active list
50(h) | 0

2. workload: 50 newly created (used-once) pages
50(h) | 50(uo)

3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(uo)

As you can see, hot pages on active list would be protected.

Note that, this implementation has a drawback that the page cannot be
promoted and will be swapped-out if re-access interval is greater than the
size of inactive list but less than the size of total(active+inactive).
To solve this potential issue, following patch will apply workingset
detection similar to the one that's already applied to file LRU.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:55 -07:00
Joonsoo Kim
ccc5dc6734 mm/vmscan: make active/inactive ratio as 1:1 for anon lru
Patch series "workingset protection/detection on the anonymous LRU list", v7.

* PROBLEM
In current implementation, newly created or swap-in anonymous page is
started on the active list.  Growing the active list results in
rebalancing active/inactive list so old pages on the active list are
demoted to the inactive list.  Hence, hot page on the active list isn't
protected at all.

Following is an example of this situation.

Assume that 50 hot pages on active list and system can contain total 100
pages.  Numbers denote the number of pages on active/inactive list (active
| inactive).  (h) stands for hot pages and (uo) stands for used-once
pages.

1. 50 hot pages on active list
50(h) | 0

2. workload: 50 newly created (used-once) pages
50(uo) | 50(h)

3. workload: another 50 newly created (used-once) pages
50(uo) | 50(uo), swap-out 50(h)

As we can see, hot pages are swapped-out and it would cause swap-in later.

* SOLUTION
Since this is what we want to avoid, this patchset implements workingset
protection.  Like as the file LRU list, newly created or swap-in anonymous
page is started on the inactive list.  Also, like as the file LRU list, if
enough reference happens, the page will be promoted.  This simple
modification changes the above example as following.

1. 50 hot pages on active list
50(h) | 0

2. workload: 50 newly created (used-once) pages
50(h) | 50(uo)

3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(uo)

hot pages remains in the active list. :)

* EXPERIMENT
I tested this scenario on my test bed and confirmed that this problem
happens on current implementation. I also checked that it is fixed by
this patchset.

* SUBJECT
workingset detection

* PROBLEM
Later part of the patchset implements the workingset detection for the
anonymous LRU list.  There is a corner case that workingset protection
could cause thrashing.  If we can avoid thrashing by workingset detection,
we can get the better performance.

Following is an example of thrashing due to the workingset protection.

1. 50 hot pages on active list
50(h) | 0

2. workload: 50 newly created (will be hot) pages
50(h) | 50(wh)

3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(wh)

4. workload: 50 (will be hot) pages
50(h) | 50(wh), swap-in 50(wh)

5. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(wh)

6. repeat 4, 5

Without workingset detection, this kind of workload cannot be promoted and
thrashing happens forever.

* SOLUTION
Therefore, this patchset implements workingset detection.  All the
infrastructure for workingset detecion is already implemented, so there is
not much work to do.  First, extend workingset detection code to deal with
the anonymous LRU list.  Then, make swap cache handles the exceptional
value for the shadow entry.  Lastly, install/retrieve the shadow value
into/from the swap cache and check the refault distance.

* EXPERIMENT
I made a test program to imitates above scenario and confirmed that
problem exists.  Then, I checked that this patchset fixes it.

My test setup is a virtual machine with 8 cpus and 6100MB memory.  But,
the amount of the memory that the test program can use is about 280 MB.
This is because the system uses large ram-backed swap and large ramdisk to
capture the trace.

Test scenario is like as below.

1. allocate cold memory (512MB)
2. allocate hot-1 memory (96MB)
3. activate hot-1 memory (96MB)
4. allocate another hot-2 memory (96MB)
5. access cold memory (128MB)
6. access hot-2 memory (96MB)
7. repeat 5, 6

Since hot-1 memory (96MB) is on the active list, the inactive list can
contains roughly 190MB pages.  hot-2 memory's re-access interval (96+128
MB) is more 190MB, so it cannot be promoted without workingset detection
and swap-in/out happens repeatedly.  With this patchset, workingset
detection works and promotion happens.  Therefore, swap-in/out occurs
less.

Here is the result. (average of 5 runs)

type swap-in swap-out
base 863240 989945
patch 681565 809273

As we can see, patched kernel do less swap-in/out.

* OVERALL TEST (ebizzy using modified random function)
ebizzy is the test program that main thread allocates lots of memory and
child threads access them randomly during the given times.  Swap-in will
happen if allocated memory is larger than the system memory.

The random function that represents the zipf distribution is used to make
hot/cold memory.  Hot/cold ratio is controlled by the parameter.  If the
parameter is high, hot memory is accessed much larger than cold one.  If
the parameter is low, the number of access on each memory would be
similar.  I uses various parameters in order to show the effect of
patchset on various hot/cold ratio workload.

My test setup is a virtual machine with 8 cpus, 1024 MB memory and 5120 MB
ram swap.

Result format is as following.

param: 1-1024-0.1
- 1 (number of thread)
- 1024 (allocated memory size, MB)
- 0.1 (zipf distribution alpha,
0.1 works like as roughly uniform random,
1.3 works like as small portion of memory is hot and the others are cold)

pswpin: smaller is better
std: standard deviation
improvement: negative is better

* single thread
           param        pswpin       std       improvement
      base 1-1024.0-0.1 14101983.40   79441.19
      prot 1-1024.0-0.1 14065875.80  136413.01  (   -0.26 )
    detect 1-1024.0-0.1 13910435.60  100804.82  (   -1.36 )
      base 1-1024.0-0.7 7998368.80   43469.32
      prot 1-1024.0-0.7 7622245.80   88318.74  (   -4.70 )
    detect 1-1024.0-0.7 7618515.20   59742.07  (   -4.75 )
      base 1-1024.0-1.3 1017400.80   38756.30
      prot 1-1024.0-1.3  940464.60   29310.69  (   -7.56 )
    detect 1-1024.0-1.3  945511.40   24579.52  (   -7.07 )
      base 1-1280.0-0.1 22895541.40   50016.08
      prot 1-1280.0-0.1 22860305.40   51952.37  (   -0.15 )
    detect 1-1280.0-0.1 22705565.20   93380.35  (   -0.83 )
      base 1-1280.0-0.7 13717645.60   46250.65
      prot 1-1280.0-0.7 12935355.80   64754.43  (   -5.70 )
    detect 1-1280.0-0.7 13040232.00   63304.00  (   -4.94 )
      base 1-1280.0-1.3 1654251.40    4159.68
      prot 1-1280.0-1.3 1522680.60   33673.50  (   -7.95 )
    detect 1-1280.0-1.3 1599207.00   70327.89  (   -3.33 )
      base 1-1536.0-0.1 31621775.40   31156.28
      prot 1-1536.0-0.1 31540355.20   62241.36  (   -0.26 )
    detect 1-1536.0-0.1 31420056.00  123831.27  (   -0.64 )
      base 1-1536.0-0.7 19620760.60   60937.60
      prot 1-1536.0-0.7 18337839.60   56102.58  (   -6.54 )
    detect 1-1536.0-0.7 18599128.00   75289.48  (   -5.21 )
      base 1-1536.0-1.3 2378142.40   20994.43
      prot 1-1536.0-1.3 2166260.60   48455.46  (   -8.91 )
    detect 1-1536.0-1.3 2183762.20   16883.24  (   -8.17 )
      base 1-1792.0-0.1 40259714.80   90750.70
      prot 1-1792.0-0.1 40053917.20   64509.47  (   -0.51 )
    detect 1-1792.0-0.1 39949736.40  104989.64  (   -0.77 )
      base 1-1792.0-0.7 25704884.40   69429.68
      prot 1-1792.0-0.7 23937389.00   79945.60  (   -6.88 )
    detect 1-1792.0-0.7 24271902.00   35044.30  (   -5.57 )
      base 1-1792.0-1.3 3129497.00   32731.86
      prot 1-1792.0-1.3 2796994.40   19017.26  (  -10.62 )
    detect 1-1792.0-1.3 2886840.40   33938.82  (   -7.75 )
      base 1-2048.0-0.1 48746924.40   50863.88
      prot 1-2048.0-0.1 48631954.40   24537.30  (   -0.24 )
    detect 1-2048.0-0.1 48509419.80   27085.34  (   -0.49 )
      base 1-2048.0-0.7 32046424.40   78624.22
      prot 1-2048.0-0.7 29764182.20   86002.26  (   -7.12 )
    detect 1-2048.0-0.7 30250315.80  101282.14  (   -5.60 )
      base 1-2048.0-1.3 3916723.60   24048.55
      prot 1-2048.0-1.3 3490781.60   33292.61  (  -10.87 )
    detect 1-2048.0-1.3 3585002.20   44942.04  (   -8.47 )

* multi thread
           param        pswpin       std       improvement
      base 8-1024.0-0.1 16219822.60  329474.01
      prot 8-1024.0-0.1 15959494.00  654597.45  (   -1.61 )
    detect 8-1024.0-0.1 15773790.80  502275.25  (   -2.75 )
      base 8-1024.0-0.7 9174107.80  537619.33
      prot 8-1024.0-0.7 8571915.00  385230.08  (   -6.56 )
    detect 8-1024.0-0.7 8489484.20  364683.00  (   -7.46 )
      base 8-1024.0-1.3 1108495.60   83555.98
      prot 8-1024.0-1.3 1038906.20   63465.20  (   -6.28 )
    detect 8-1024.0-1.3  941817.80   32648.80  (  -15.04 )
      base 8-1280.0-0.1 25776114.20  450480.45
      prot 8-1280.0-0.1 25430847.00  465627.07  (   -1.34 )
    detect 8-1280.0-0.1 25282555.00  465666.55  (   -1.91 )
      base 8-1280.0-0.7 15218968.00  702007.69
      prot 8-1280.0-0.7 13957947.80  492643.86  (   -8.29 )
    detect 8-1280.0-0.7 14158331.20  238656.02  (   -6.97 )
      base 8-1280.0-1.3 1792482.80   30512.90
      prot 8-1280.0-1.3 1577686.40   34002.62  (  -11.98 )
    detect 8-1280.0-1.3 1556133.00   22944.79  (  -13.19 )
      base 8-1536.0-0.1 33923761.40  575455.85
      prot 8-1536.0-0.1 32715766.20  300633.51  (   -3.56 )
    detect 8-1536.0-0.1 33158477.40  117764.51  (   -2.26 )
      base 8-1536.0-0.7 20628907.80  303851.34
      prot 8-1536.0-0.7 19329511.20  341719.31  (   -6.30 )
    detect 8-1536.0-0.7 20013934.00  385358.66  (   -2.98 )
      base 8-1536.0-1.3 2588106.40  130769.20
      prot 8-1536.0-1.3 2275222.40   89637.06  (  -12.09 )
    detect 8-1536.0-1.3 2365008.40  124412.55  (   -8.62 )
      base 8-1792.0-0.1 43328279.20  946469.12
      prot 8-1792.0-0.1 41481980.80  525690.89  (   -4.26 )
    detect 8-1792.0-0.1 41713944.60  406798.93  (   -3.73 )
      base 8-1792.0-0.7 27155647.40  536253.57
      prot 8-1792.0-0.7 24989406.80  502734.52  (   -7.98 )
    detect 8-1792.0-0.7 25524806.40  263237.87  (   -6.01 )
      base 8-1792.0-1.3 3260372.80  137907.92
      prot 8-1792.0-1.3 2879187.80   63597.26  (  -11.69 )
    detect 8-1792.0-1.3 2892962.20   33229.13  (  -11.27 )
      base 8-2048.0-0.1 50583989.80  710121.48
      prot 8-2048.0-0.1 49599984.40  228782.42  (   -1.95 )
    detect 8-2048.0-0.1 50578596.00  660971.66  (   -0.01 )
      base 8-2048.0-0.7 33765479.60  812659.55
      prot 8-2048.0-0.7 30767021.20  462907.24  (   -8.88 )
    detect 8-2048.0-0.7 32213068.80  211884.24  (   -4.60 )
      base 8-2048.0-1.3 3941675.80   28436.45
      prot 8-2048.0-1.3 3538742.40   76856.08  (  -10.22 )
    detect 8-2048.0-1.3 3579397.80   58630.95  (   -9.19 )

As we can see, all the cases show improvement.  Especially, test case with
zipf distribution 1.3 show more improvements.  It means that if there is a
hot/cold tendency in anon pages, this patchset works better.

This patch (of 6):

Current implementation of LRU management for anonymous page has some
problems.  Most important one is that it doesn't protect the workingset,
that is, pages on the active LRU list.  Although, this problem will be
fixed in the following patchset, the preparation is required and this
patch does it.

What following patch does is to implement workingset protection.  After
the following patchset, newly created or swap-in pages will start their
lifetime on the inactive list.  If inactive list is too small, there is
not enough chance to be referenced and the page cannot become the
workingset.

In order to provide the newly anonymous or swap-in pages enough chance to
be referenced again, this patch makes active/inactive LRU ratio as 1:1.

This is just a temporary measure.  Later patch in the series introduces
workingset detection for anonymous LRU that will be used to better decide
if pages should start on the active and inactive list.  Afterwards this
patch is effectively reverted.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/1595490560-15117-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1595490560-15117-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:57:55 -07:00
Shakeel Butt
912c05720f mm: vmscan: consistent update to pgrefill
The vmstat pgrefill is useful together with pgscan and pgsteal stats to
measure the reclaim efficiency.  However vmstat's pgrefill is not updated
consistently at system level.  It gets updated for both global and memcg
reclaim however pgscan and pgsteal are updated for only global reclaim.
So, update pgrefill only for global reclaim.  If someone is interested in
the stats representing both system level as well as memcg level reclaim,
then consult the root memcg's memory.stat instead of /proc/vmstat.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20200711011459.1159929-1-shakeelb@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:29 -07:00
dylan-meiners
238c30468f mm/vmscan.c: fix typo
Change "optizimation" to "optimization".

Signed-off-by: dylan-meiners <spacct.spacct@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200609185144.10049-1-spacct.spacct@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:29 -07:00
David Hildenbrand
0a18e60788 mm: remove vm_total_pages
The global variable "vm_total_pages" is a relic from older days.  There is
only a single user that reads the variable - build_all_zonelists() - and
the first thing it does is update it.

Use a local variable in build_all_zonelists() instead and remove the
global variable.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:28 -07:00
Johannes Weiner
e22c6ed90a mm: memcontrol: don't count limit-setting reclaim as memory pressure
When an outside process lowers one of the memory limits of a cgroup (or
uses the force_empty knob in cgroup1), direct reclaim is performed in the
context of the write(), in order to directly enforce the new limit and
have it being met by the time the write() returns.

Currently, this reclaim activity is accounted as memory pressure in the
cgroup that the writer(!) belongs to.  This is unexpected.  It
specifically causes problems for senpai
(https://github.com/facebookincubator/senpai), which is an agent that
routinely adjusts the memory limits and performs associated reclaim work
in tens or even hundreds of cgroups running on the host.  The cgroup that
senpai is running in itself will report elevated levels of memory
pressure, even though it itself is under no memory shortage or any sort of
distress.

Move the psi annotation from the central cgroup reclaim function to
callsites in the allocation context, and thereby no longer count any
limit-setting reclaim as memory pressure.  If the newly set limit causes
the workload inside the cgroup into direct reclaim, that of course will
continue to count as memory pressure.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200728135210.379885-2-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:26 -07:00
Chris Down
45c7f7e1ef mm, memcg: decouple e{low,min} state mutations from protection checks
mem_cgroup_protected currently is both used to set effective low and min
and return a mem_cgroup_protection based on the result.  As a user, this
can be a little unexpected: it appears to be a simple predicate function,
if not for the big warning in the comment above about the order in which
it must be executed.

This change makes it so that we separate the state mutations from the
actual protection checks, which makes it more obvious where we need to be
careful mutating internal state, and where we are simply checking and
don't need to worry about that.

[mhocko@suse.com - don't check protection on root memcgs]

Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Link: http://lkml.kernel.org/r/ff3f915097fcee9f6d7041c084ef92d16aaeb56a.1594638158.git.chris@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:25 -07:00
Yafang Shao
22f7496f0b mm, memcg: avoid stale protection values when cgroup is above protection
Patch series "mm, memcg: memory.{low,min} reclaim fix & cleanup", v4.

This series contains a fix for a edge case in my earlier protection
calculation patches, and a patch to make the area overall a little more
robust to hopefully help avoid this in future.

This patch (of 2):

A cgroup can have both memory protection and a memory limit to isolate it
from its siblings in both directions - for example, to prevent it from
being shrunk below 2G under high pressure from outside, but also from
growing beyond 4G under low pressure.

Commit 9783aa9917 ("mm, memcg: proportional memory.{low,min} reclaim")
implemented proportional scan pressure so that multiple siblings in excess
of their protection settings don't get reclaimed equally but instead in
accordance to their unprotected portion.

During limit reclaim, this proportionality shouldn't apply of course:
there is no competition, all pressure is from within the cgroup and should
be applied as such.  Reclaim should operate at full efficiency.

However, mem_cgroup_protected() never expected anybody to look at the
effective protection values when it indicated that the cgroup is above its
protection.  As a result, a query during limit reclaim may return stale
protection values that were calculated by a previous reclaim cycle in
which the cgroup did have siblings.

When this happens, reclaim is unnecessarily hesitant and potentially slow
to meet the desired limit.  In theory this could lead to premature OOM
kills, although it's not obvious this has occurred in practice.

Workaround the problem by special casing reclaim roots in
mem_cgroup_protection.  These memcgs are never participating in the
reclaim protection because the reclaim is internal.

We have to ignore effective protection values for reclaim roots because
mem_cgroup_protected might be called from racing reclaim contexts with
different roots.  Calculation is relying on root -> leaf tree traversal
therefore top-down reclaim protection invariants should hold.  The only
exception is the reclaim root which should have effective protection set
to 0 but that would be problematic for the following setup:

 Let's have global and A's reclaim in parallel:
  |
  A (low=2G, usage = 3G, max = 3G, children_low_usage = 1.5G)
  |\
  | C (low = 1G, usage = 2.5G)
  B (low = 1G, usage = 0.5G)

 for A reclaim we have
 B.elow = B.low
 C.elow = C.low

 For the global reclaim
 A.elow = A.low
 B.elow = min(B.usage, B.low) because children_low_usage <= A.elow
 C.elow = min(C.usage, C.low)

 With the effective values resetting we have A reclaim
 A.elow = 0
 B.elow = B.low
 C.elow = C.low

 and global reclaim could see the above and then
 B.elow = C.elow = 0 because children_low_usage > A.elow

Which means that protected memcgs would get reclaimed.

In future we would like to make mem_cgroup_protected more robust against
racing reclaim contexts but that is likely more complex solution than this
simple workaround.

[hannes@cmpxchg.org - large part of the changelog]
[mhocko@suse.com - workaround explanation]
[chris@chrisdown.name - retitle]

Fixes: 9783aa9917 ("mm, memcg: proportional memory.{low,min} reclaim")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/cover.1594638158.git.chris@chrisdown.name
Link: http://lkml.kernel.org/r/044fb8ecffd001c7905d27c0c2ad998069fdc396.1594638158.git.chris@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:25 -07:00
Roman Gushchin
d42f3245c7 mm: memcg: convert vmstat slab counters to bytes
In order to prepare for per-object slab memory accounting, convert
NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE vmstat items to bytes.

To make it obvious, rename them to NR_SLAB_RECLAIMABLE_B and
NR_SLAB_UNRECLAIMABLE_B (similar to NR_KERNEL_STACK_KB).

Internally global and per-node counters are stored in pages, however memcg
and lruvec counters are stored in bytes.  This scheme may look weird, but
only for now.  As soon as slab pages will be shared between multiple
cgroups, global and node counters will reflect the total number of slab
pages.  However memcg and lruvec counters will be used for per-memcg slab
memory tracking, which will take separate kernel objects in the account.
Keeping global and node counters in pages helps to avoid additional
overhead.

The size of slab memory shouldn't exceed 4Gb on 32-bit machines, so it
will fit into atomic_long_t we use for vmstats.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-4-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:24 -07:00
Johannes Weiner
31d8fcac00 mm: workingset: age nonresident information alongside anonymous pages
Patch series "fix for "mm: balance LRU lists based on relative
thrashing" patchset"

This patchset fixes some problems of the patchset, "mm: balance LRU
lists based on relative thrashing", which is now merged on the mainline.

Patch "mm: workingset: let cache workingset challenge anon fix" is the
result of discussion with Johannes.  See following link.

  http://lkml.kernel.org/r/20200520232525.798933-6-hannes@cmpxchg.org

And, the other two are minor things which are found when I try to rebase
my patchset.

This patch (of 3):

After ("mm: workingset: let cache workingset challenge anon fix"), we
compare refault distances to active_file + anon.  But age of the
non-resident information is only driven by the file LRU.  As a result,
we may overestimate the recency of any incoming refaults and activate
them too eagerly, causing unnecessary LRU churn in certain situations.

Make anon aging drive nonresident age as well to address that.

Link: http://lkml.kernel.org/r/1592288204-27734-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1592288204-27734-2-git-send-email-iamjoonsoo.kim@lge.com
Fixes: 34e58cac6d ("mm: workingset: let cache workingset challenge anon")
Reported-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan.kim@gmail.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>
2020-06-26 00:27:37 -07:00
Ethon Paul
55b65a57c2 mm/vmsan: fix some typos in comment
There are some typos, fix them.

s/regsitration/registration
s/santity/sanity
s/decremeting/decrementing

Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411071544.16222-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 19:06:23 -07:00
Johannes Weiner
d483a5dd00 mm: vmscan: limit the range of LRU type balancing
When LRU cost only shows up on one list, we abruptly stop scanning that
list altogether.  That's an extreme reaction: by the time the other list
starts thrashing and the pendulum swings back, we may have no recent age
information on the first list anymore, and we could have significant
latencies until the scanner has caught up.

Soften this change in the feedback system by ensuring that no list
receives less than a third of overall pressure, and only distribute the
other 66% according to LRU cost.  This ensures that we maintain a minimum
rate of aging on the entire workingset while it's being pressured, while
still allowing a generous rate of convergence when the relative sizes of
the lists need to adjust.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-15-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:49 -07:00
Johannes Weiner
96f8bf4fb1 mm: vmscan: reclaim writepage is IO cost
The VM tries to balance reclaim pressure between anon and file so as to
reduce the amount of IO incurred due to the memory shortage.  It already
counts refaults and swapins, but in addition it should also count
writepage calls during reclaim.

For swap, this is obvious: it's IO that wouldn't have occurred if the
anonymous memory hadn't been under memory pressure.  From a relative
balancing point of view this makes sense as well: even if anon is cold and
reclaimable, a cache that isn't thrashing may have equally cold pages that
don't require IO to reclaim.

For file writeback, it's trickier: some of the reclaim writepage IO would
have likely occurred anyway due to dirty expiration.  But not all of it -
premature writeback reduces batching and generates additional writes.
Since the flushers are already woken up by the time the VM starts writing
cache pages one by one, let's assume that we'e likely causing writes that
wouldn't have happened without memory pressure.  In addition, the per-page
cost of IO would have probably been much cheaper if written in larger
batches from the flusher thread rather than the single-page-writes from
kswapd.

For our purposes - getting the trend right to accelerate convergence on a
stable state that doesn't require paging at all - this is sufficiently
accurate.  If we later wanted to optimize for sustained thrashing, we can
still refine the measurements.

Count all writepage calls from kswapd as IO cost toward the LRU that the
page belongs to.

Why do this dynamically?  Don't we know in advance that anon pages require
IO to reclaim, and so could build in a static bias?

First, scanning is not the same as reclaiming.  If all the anon pages are
referenced, we may not swap for a while just because we're scanning the
anon list.  During this time, however, it's important that we age
anonymous memory and the page cache at the same rate so that their
hot-cold gradients are comparable.  Everything else being equal, we still
want to reclaim the coldest memory overall.

Second, we keep copies in swap unless the page changes.  If there is
swap-backed data that's mostly read (tmpfs file) and has been swapped out
before, we can reclaim it without incurring additional IO.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-14-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:49 -07:00
Johannes Weiner
7cf111bc39 mm: vmscan: determine anon/file pressure balance at the reclaim root
We split the LRU lists into anon and file, and we rebalance the scan
pressure between them when one of them begins thrashing: if the file cache
experiences workingset refaults, we increase the pressure on anonymous
pages; if the workload is stalled on swapins, we increase the pressure on
the file cache instead.

With cgroups and their nested LRU lists, we currently don't do this
correctly.  While recursive cgroup reclaim establishes a relative LRU
order among the pages of all involved cgroups, LRU pressure balancing is
done on an individual cgroup LRU level.  As a result, when one cgroup is
thrashing on the filesystem cache while a sibling may have cold anonymous
pages, pressure doesn't get equalized between them.

This patch moves LRU balancing decision to the root of reclaim - the same
level where the LRU order is established.

It does this by tracking LRU cost recursively, so that every level of the
cgroup tree knows the aggregate LRU cost of all memory within its domain.
When the page scanner calculates the scan balance for any given individual
cgroup's LRU list, it uses the values from the ancestor cgroup that
initiated the reclaim cycle.

If one sibling is then thrashing on the cache, it will tip the pressure
balance inside its ancestors, and the next hierarchical reclaim iteration
will go more after the anon pages in the tree.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-13-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:49 -07:00
Johannes Weiner
314b57fb04 mm: balance LRU lists based on relative thrashing
Since the LRUs were split into anon and file lists, the VM has been
balancing between page cache and anonymous pages based on per-list ratios
of scanned vs.  rotated pages.  In most cases that tips page reclaim
towards the list that is easier to reclaim and has the fewest actively
used pages, but there are a few problems with it:

1. Refaults and LRU rotations are weighted the same way, even though
   one costs IO and the other costs a bit of CPU.

2. The less we scan an LRU list based on already observed rotations,
   the more we increase the sampling interval for new references, and
   rotations become even more likely on that list. This can enter a
   death spiral in which we stop looking at one list completely until
   the other one is all but annihilated by page reclaim.

Since commit a528910e12 ("mm: thrash detection-based file cache sizing")
we have refault detection for the page cache.  Along with swapin events,
they are good indicators of when the file or anon list, respectively, is
too small for its workingset and needs to grow.

For example, if the page cache is thrashing, the cache pages need more
time in memory, while there may be colder pages on the anonymous list.
Likewise, if swapped pages are faulting back in, it indicates that we
reclaim anonymous pages too aggressively and should back off.

Replace LRU rotations with refaults and swapins as the basis for relative
reclaim cost of the two LRUs.  This will have the VM target list balances
that incur the least amount of IO on aggregate.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-12-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:49 -07:00
Johannes Weiner
264e90cc07 mm: only count actual rotations as LRU reclaim cost
When shrinking the active file list we rotate referenced pages only when
they're in an executable mapping.  The others get deactivated.  When it
comes to balancing scan pressure, though, we count all referenced pages as
rotated, even the deactivated ones.  Yet they do not carry the same cost
to the system: the deactivated page *might* refault later on, but the
deactivation is tangible progress toward freeing pages; rotations on the
other hand cost time and effort without getting any closer to freeing
memory.

Don't treat both events as equal.  The following patch will hook up LRU
balancing to cache and anon refaults, which are a much more concrete cost
signal for reclaiming one list over the other.  Thus, remove the maybe-IO
cost bias from page references, and only note the CPU cost for actual
rotations that prevent the pages from getting reclaimed.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-11-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:49 -07:00
Johannes Weiner
1431d4d11a mm: base LRU balancing on an explicit cost model
Currently, scan pressure between the anon and file LRU lists is balanced
based on a mixture of reclaim efficiency and a somewhat vague notion of
"value" of having certain pages in memory over others.  That concept of
value is problematic, because it has caused us to count any event that
remotely makes one LRU list more or less preferrable for reclaim, even
when these events are not directly comparable and impose very different
costs on the system.  One example is referenced file pages that we still
deactivate and referenced anonymous pages that we actually rotate back to
the head of the list.

There is also conceptual overlap with the LRU algorithm itself.  By
rotating recently used pages instead of reclaiming them, the algorithm
already biases the applied scan pressure based on page value.  Thus, when
rebalancing scan pressure due to rotations, we should think of reclaim
cost, and leave assessing the page value to the LRU algorithm.

Lastly, considering both value-increasing as well as value-decreasing
events can sometimes cause the same type of event to be counted twice,
i.e.  how rotating a page increases the LRU value, while reclaiming it
succesfully decreases the value.  In itself this will balance out fine,
but it quietly skews the impact of events that are only recorded once.

The abstract metric of "value", the murky relationship with the LRU
algorithm, and accounting both negative and positive events make the
current pressure balancing model hard to reason about and modify.

This patch switches to a balancing model of accounting the concrete,
actually observed cost of reclaiming one LRU over another.  For now, that
cost includes pages that are scanned but rotated back to the list head.
Subsequent patches will add consideration for IO caused by refaulting of
recently evicted pages.

Replace struct zone_reclaim_stat with two cost counters in the lruvec, and
make everything that affects cost go through a new lru_note_cost()
function.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-9-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:48 -07:00
Johannes Weiner
a4fe1631f3 mm: vmscan: drop unnecessary div0 avoidance rounding in get_scan_count()
When we calculate the relative scan pressure between the anon and file LRU
lists, we have to assume that reclaim_stat can contain zeroes.  To avoid
div0 crashes, we add 1 to all denominators like so:

        anon_prio = swappiness;
        file_prio = 200 - anon_prio;

	[...]

        /*
         * The amount of pressure on anon vs file pages is inversely
         * proportional to the fraction of recently scanned pages on
         * each list that were recently referenced and in active use.
         */
        ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
        ap /= reclaim_stat->recent_rotated[0] + 1;

        fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
        fp /= reclaim_stat->recent_rotated[1] + 1;
        spin_unlock_irq(&pgdat->lru_lock);

        fraction[0] = ap;
        fraction[1] = fp;
        denominator = ap + fp + 1;

While reclaim_stat can contain 0, it's not actually possible for ap + fp
to be 0.  One of anon_prio or file_prio could be zero, but they must still
add up to 200.  And the reclaim_stat fraction, due to the +1 in there, is
always at least 1.  So if one of the two numerators is 0, the other one
can't be.  ap + fp is always at least 1.  Drop the + 1.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-8-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:48 -07:00
Johannes Weiner
c843966c55 mm: allow swappiness that prefers reclaiming anon over the file workingset
With the advent of fast random IO devices (SSDs, PMEM) and in-memory swap
devices such as zswap, it's possible for swap to be much faster than
filesystems, and for swapping to be preferable over thrashing filesystem
caches.

Allow setting swappiness - which defines the rough relative IO cost of
cache misses between page cache and swap-backed pages - to reflect such
situations by making the swap-preferred range configurable.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-4-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:48 -07:00
Johannes Weiner
497a6c1b09 mm: keep separate anon and file statistics on page reclaim activity
Having statistics on pages scanned and pages reclaimed for both anon and
file pages makes it easier to evaluate changes to LRU balancing.

While at it, clean up the stat-keeping mess for isolation, putback,
reclaim stats etc.  a bit: first the physical LRU operation (isolation and
putback), followed by vmstats, reclaim_stats, and then vm events.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-3-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:48 -07:00
Qiwu Chen
df3a45f9d8 mm/vmscan: update the comment of should_continue_reclaim()
try_to_compact_zone() has been replaced by try_to_compact_pages(), which
is necessary to be updated in the comment of should_continue_reclaim().

Signed-off-by: Qiwu Chen <chenqiwu@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200501034907.22991-1-chenqiwu@xiaomi.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:47 -07:00
Maninder Singh
730ec8c01a mm/vmscan.c: change prototype for shrink_page_list
commit 3c710c1ad1 ("mm, vmscan extract shrink_page_list reclaim counters
into a struct") changed data type for the function, so changing return
type for funciton and its caller.

Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1588168259-25604-1-git-send-email-maninder1.s@samsung.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:47 -07:00
Jaewon Kim
1f318a9b0d mm/vmscan: count layzfree pages and fix nr_isolated_* mismatch
Fix an nr_isolate_* mismatch problem between cma and dirty lazyfree pages.

If try_to_unmap_one is used for reclaim and it detects a dirty lazyfree
page, then the lazyfree page is changed to a normal anon page having
SwapBacked by commit 802a3a92ad ("mm: reclaim MADV_FREE pages").  Even
with the change, reclaim context correctly counts isolated files because
it uses is_file_lru to distinguish file.  And the change to anon is not
happened if try_to_unmap_one is used for migration.  So migration context
like compaction also correctly counts isolated files even though it uses
page_is_file_lru insted of is_file_lru.  Recently page_is_file_cache was
renamed to page_is_file_lru by commit 9de4f22a60 ("mm: code cleanup for
MADV_FREE").

But the nr_isolate_* mismatch problem happens on cma alloc.  There is
reclaim_clean_pages_from_list which is being used only by cma.  It was
introduced by commit 02c6de8d75 ("mm: cma: discard clean pages during
contiguous allocation instead of migration") to reclaim clean file pages
without migration.  The cma alloc uses both reclaim_clean_pages_from_list
and migrate_pages, and it uses page_is_file_lru to count isolated files.
If there are dirty lazyfree pages allocated from cma memory region, the
pages are counted as isolated file at the beginging but are counted as
isolated anon after finished.

Mem-Info:
Node 0 active_anon:3045904kB inactive_anon:611448kB active_file:14892kB inactive_file:205636kB unevictable:10416kB isolated(anon):0kB isolated(file):37664kB mapped:630216kB dirty:384kB writeback:0kB shmem:42576kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no

Like log above, there were too much isolated files, 37664kB, which
triggers too_many_isolated in reclaim even when there is no actually
isolated file in system wide.  It could be reproducible by running two
programs, writing on MADV_FREE page and doing cma alloc, respectively.
Although isolated anon is 0, I found that the internal value of isolated
anon was the negative value of isolated file.

Fix this by compensating the isolated count for both LRU lists.  Count
non-discarded lazyfree pages in shrink_page_list, then compensate the
counted number in reclaim_clean_pages_from_list.

Reported-by: Yong-Taek Lee <ytk.lee@samsung.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200426011718.30246-1-jaewon31.kim@samsung.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:47 -07:00
Wei Yang
a892cb6b97 mm/vmscan.c: use update_lru_size() in update_lru_sizes()
We already defined the helper update_lru_size().

Let's use this to reduce code duplication.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200331221550.1011-1-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:47 -07:00
Matthew Wilcox (Oracle)
ff45fc3ca0 mm: simplify calling a compound page destructor
None of the three callers of get_compound_page_dtor() want to know the
value; they just want to call the function.  Replace it with
destroy_compound_page() which calls the dtor for them.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200517105051.9352-1-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:47 -07:00
Joonsoo Kim
97a225e69a mm/page_alloc: integrate classzone_idx and high_zoneidx
classzone_idx is just different name for high_zoneidx now.  So, integrate
them and add some comment to struct alloc_context in order to reduce
future confusion about the meaning of this variable.

The accessor, ac_classzone_idx() is also removed since it isn't needed
after integration.

In addition to integration, this patch also renames high_zoneidx to
highest_zoneidx since it represents more precise meaning.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/1587095923-7515-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:44 -07:00
NeilBrown
a37b0715dd mm/writeback: replace PF_LESS_THROTTLE with PF_LOCAL_THROTTLE
PF_LESS_THROTTLE exists for loop-back nfsd (and a similar need in the
loop block driver and callers of prctl(PR_SET_IO_FLUSHER)), where a
daemon needs to write to one bdi (the final bdi) in order to free up
writes queued to another bdi (the client bdi).

The daemon sets PF_LESS_THROTTLE and gets a larger allowance of dirty
pages, so that it can still dirty pages after other processses have been
throttled.  The purpose of this is to avoid deadlock that happen when
the PF_LESS_THROTTLE process must write for any dirty pages to be freed,
but it is being thottled and cannot write.

This approach was designed when all threads were blocked equally,
independently on which device they were writing to, or how fast it was.
Since that time the writeback algorithm has changed substantially with
different threads getting different allowances based on non-trivial
heuristics.  This means the simple "add 25%" heuristic is no longer
reliable.

The important issue is not that the daemon needs a *larger* dirty page
allowance, but that it needs a *private* dirty page allowance, so that
dirty pages for the "client" bdi that it is helping to clear (the bdi
for an NFS filesystem or loop block device etc) do not affect the
throttling of the daemon writing to the "final" bdi.

This patch changes the heuristic so that the task is not throttled when
the bdi it is writing to has a dirty page count below below (or equal
to) the free-run threshold for that bdi.  This ensures it will always be
able to have some pages in flight, and so will not deadlock.

In a steady-state, it is expected that PF_LOCAL_THROTTLE tasks might
still be throttled by global threshold, but that is acceptable as it is
only the deadlock state that is interesting for this flag.

This approach of "only throttle when target bdi is busy" is consistent
with the other use of PF_LESS_THROTTLE in current_may_throttle(), were
it causes attention to be focussed only on the target bdi.

So this patch
 - renames PF_LESS_THROTTLE to PF_LOCAL_THROTTLE,
 - removes the 25% bonus that that flag gives, and
 - If PF_LOCAL_THROTTLE is set, don't delay at all unless the
   global and the local free-run thresholds are exceeded.

Note that previously realtime threads were treated the same as
PF_LESS_THROTTLE threads.  This patch does *not* change the behvaiour
for real-time threads, so it is now different from the behaviour of nfsd
and loop tasks.  I don't know what is wanted for realtime.

[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Chuck Lever <chuck.lever@oracle.com>	[nfsd]
Cc: Christoph Hellwig <hch@lst.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Link: http://lkml.kernel.org/r/87ftbf7gs3.fsf@notabene.neil.brown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:08 -07:00
Qiwu Chen
17e34526f0 mm/vmscan: remove unnecessary argument description of isolate_lru_pages()
Since commit a9e7c39fa9 ("mm/vmscan.c: remove 7th argument of
isolate_lru_pages()"), the explanation of 'mode' argument has been
unnecessary.  Let's remove it.

Signed-off-by: Qiwu Chen <chenqiwu@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200501090346.2894-1-chenqiwu@xiaomi.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-07 19:27:21 -07:00
Huang Ying
9de4f22a60 mm: code cleanup for MADV_FREE
Some comments for MADV_FREE is revised and added to help people understand
the MADV_FREE code, especially the page flag, PG_swapbacked.  This makes
page_is_file_cache() isn't consistent with its comments.  So the function
is renamed to page_is_file_lru() to make them consistent again.  All these
are put in one patch as one logical change.

Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200317100342.2730705-1-ying.huang@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 10:43:38 -07:00
Mateusz Nosek
c4ecddfff1 mm/vmscan.c: do_try_to_free_pages(): clean code by removing unnecessary assignment
sc->memcg_low_skipped resets skipped_deactivate to 0 but this is not
needed as this code path is never reachable with skipped_deactivate != 0
due to previous sc->skipped_deactivate branch.

[mhocko@kernel.org: rewrite changelog]
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20200319165938.23354-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:31 -07:00