This reverts commit 9d6fd2c3e9 ("Merge remote-tracking branch
'msm-4.4/tmp-510d0a3f' into msm-4.4"), because it breaks the
dump parsing tools due to kernel can be loaded anywhere in the memory
now and not fixed at linear mapping.
Change-Id: Id416f0a249d803442847d09ac47781147b0d0ee6
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
On arm systems the spin on owner optimization can intermittently cause a
lockup that's usually as long as the waiting thread's cpu timeslice. The
repeated mutex aquisitions + atomics in a single spinning thread can
completely lock out the owner from releasing the kernel mutex. The
owner needs to acquire a spinlock on the relase path and this spinlock
can share a monitor with the other locks and atomics on the waiter path.
Rate limit the waiter so that the thread releasing the mutex never
is starved.
Bug 23036902
Change-Id: Ie1b64275a0c6141f94faaf3e63fcbf9b5438140c
Signed-off-by: Riley Andrews <riandrews@google.com>
Git-commit: 84d8ce7e0025cac60a8a379a7ee3e59d640fbc03
Git-repo: https://android.googlesource.com/kernel/msm.git
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
* msm-4.4/tmp-510d0a3f:
Linux 4.4.11
nf_conntrack: avoid kernel pointer value leak in slab name
drm/radeon: fix DP link training issue with second 4K monitor
drm/i915/bdw: Add missing delay during L3 SQC credit programming
drm/i915: Bail out of pipe config compute loop on LPT
drm/radeon: fix PLL sharing on DCE6.1 (v2)
Revert "[media] videobuf2-v4l2: Verify planes array in buffer dequeueing"
Input: max8997-haptic - fix NULL pointer dereference
get_rock_ridge_filename(): handle malformed NM entries
tools lib traceevent: Do not reassign parg after collapse_tree()
qla1280: Don't allocate 512kb of host tags
atomic_open(): fix the handling of create_error
regulator: axp20x: Fix axp22x ldo_io voltage ranges
regulator: s2mps11: Fix invalid selector mask and voltages for buck9
workqueue: fix rebind bound workers warning
ARM: dts: at91: sam9x5: Fix the memory range assigned to the PMC
vfs: rename: check backing inode being equal
vfs: add vfs_select_inode() helper
perf/core: Disable the event on a truncated AUX record
regmap: spmi: Fix regmap_spmi_ext_read in multi-byte case
pinctrl: at91-pio4: fix pull-up/down logic
spi: spi-ti-qspi: Handle truncated frames properly
spi: spi-ti-qspi: Fix FLEN and WLEN settings if bits_per_word is overridden
spi: pxa2xx: Do not detect number of enabled chip selects on Intel SPT
ALSA: hda - Fix broken reconfig
ALSA: hda - Fix white noise on Asus UX501VW headset
ALSA: hda - Fix subwoofer pin on ASUS N751 and N551
ALSA: usb-audio: Yet another Phoneix Audio device quirk
ALSA: usb-audio: Quirk for yet another Phoenix Audio devices (v2)
crypto: testmgr - Use kmalloc memory for RSA input
crypto: hash - Fix page length clamping in hash walk
crypto: qat - fix invalid pf2vf_resp_wq logic
s390/mm: fix asce_bits handling with dynamic pagetable levels
zsmalloc: fix zs_can_compact() integer overflow
ocfs2: fix posix_acl_create deadlock
ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang
net/route: enforce hoplimit max value
tcp: refresh skb timestamp at retransmit time
net: thunderx: avoid exposing kernel stack
net: fix a kernel infoleak in x25 module
uapi glibc compat: fix compile errors when glibc net/if.h included before linux/if.h MIME-Version: 1.0
bridge: fix igmp / mld query parsing
net: bridge: fix old ioctl unlocked net device walk
VSOCK: do not disconnect socket when peer has shutdown SEND only
net/mlx4_en: Fix endianness bug in IPV6 csum calculation
net: fix infoleak in rtnetlink
net: fix infoleak in llc
net: fec: only clear a queue's work bit if the queue was emptied
netem: Segment GSO packets on enqueue
sch_dsmark: update backlog as well
sch_htb: update backlog as well
net_sched: update hierarchical backlog too
net_sched: introduce qdisc_replace() helper
gre: do not pull header in ICMP error processing
net: Implement net_dbg_ratelimited() for CONFIG_DYNAMIC_DEBUG case
samples/bpf: fix trace_output example
bpf: fix check_map_func_compatibility logic
bpf: fix refcnt overflow
bpf: fix double-fdput in replace_map_fd_with_map_ptr()
net/mlx4_en: fix spurious timestamping callbacks
ipv4/fib: don't warn when primary address is missing if in_dev is dead
net/mlx5e: Fix minimum MTU
net/mlx5e: Device's mtu field is u16 and not int
openvswitch: use flow protocol when recalculating ipv6 checksums
atl2: Disable unimplemented scatter/gather feature
vlan: pull on __vlan_insert_tag error path and fix csum correction
net: use skb_postpush_rcsum instead of own implementations
cdc_mbim: apply "NDP to end" quirk to all Huawei devices
bpf/verifier: reject invalid LD_ABS | BPF_DW instruction
net: sched: do not requeue a NULL skb
packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface
route: do not cache fib route info on local routes with oif
decnet: Do not build routes to devices without decnet private data.
parisc: Use generic extable search and sort routines
arm64: kasan: Use actual memory node when populating the kernel image shadow
arm64: mm: treat memstart_addr as a signed quantity
arm64: lse: deal with clobbered IP registers after branch via PLT
arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
arm64: consistently use p?d_set_huge
arm64: fix KASLR boot-time I-cache maintenance
arm64: hugetlb: partial revert of 66b3923a1a0f
arm64: make irq_stack_ptr more robust
arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomness
efi: stub: use high allocation for converted command line
efi: stub: add implementation of efi_random_alloc()
efi: stub: implement efi_get_random_bytes() based on EFI_RNG_PROTOCOL
arm64: kaslr: randomize the linear region
arm64: add support for kernel ASLR
arm64: add support for building vmlinux as a relocatable PIE binary
arm64: switch to relative exception tables
extable: add support for relative extables to search and sort routines
scripts/sortextable: add support for ET_DYN binaries
arm64: futex.h: Add missing PAN toggling
arm64: make asm/elf.h available to asm files
arm64: avoid dynamic relocations in early boot code
arm64: avoid R_AARCH64_ABS64 relocations for Image header fields
arm64: add support for module PLTs
arm64: move brk immediate argument definitions to separate header
arm64: mm: use bit ops rather than arithmetic in pa/va translations
arm64: mm: only perform memstart_addr sanity check if DEBUG_VM
arm64: User die() instead of panic() in do_page_fault()
arm64: allow kernel Image to be loaded anywhere in physical memory
arm64: defer __va translation of initrd_start and initrd_end
arm64: move kernel image to base of vmalloc area
arm64: kvm: deal with kernel symbols outside of linear mapping
arm64: decouple early fixmap init from linear mapping
arm64: pgtable: implement static [pte|pmd|pud]_offset variants
arm64: introduce KIMAGE_VADDR as the virtual base of the kernel region
arm64: add support for ioremap() block mappings
arm64: prevent potential circular header dependencies in asm/bug.h
of/fdt: factor out assignment of initrd_start/initrd_end
of/fdt: make memblock minimum physical address arch configurable
arm64: Remove the get_thread_info() function
arm64: kernel: Don't toggle PAN on systems with UAO
arm64: cpufeature: Test 'matches' pointer to find the end of the list
arm64: kernel: Add support for User Access Override
arm64: add ARMv8.2 id_aa64mmfr2 boiler plate
arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro
arm64: use local label prefixes for __reg_num symbols
arm64: vdso: Mark vDSO code as read-only
arm64: ubsan: select ARCH_HAS_UBSAN_SANITIZE_ALL
arm64: ptdump: Indicate whether memory should be faulting
arm64: Add support for ARCH_SUPPORTS_DEBUG_PAGEALLOC
arm64: Drop alloc function from create_mapping
arm64: prefetch: add missing #include for spin_lock_prefetch
arm64: lib: patch in prfm for copy_page if requested
arm64: lib: improve copy_page to deal with 128 bytes at a time
arm64: prefetch: add alternative pattern for CPUs without a prefetcher
arm64: prefetch: don't provide spin_lock_prefetch with LSE
arm64: allow vmalloc regions to be set with set_memory_*
arm64: kernel: implement ACPI parking protocol
arm64: mm: create new fine-grained mappings at boot
arm64: ensure _stext and _etext are page-aligned
arm64: mm: allow passing a pgdir to alloc_init_*
arm64: mm: allocate pagetables anywhere
arm64: mm: use fixmap when creating page tables
arm64: mm: add functions to walk tables in fixmap
arm64: mm: add __{pud,pgd}_populate
arm64: mm: avoid redundant __pa(__va(x))
arm64: mm: add functions to walk page tables by PA
arm64: mm: move pte_* macros
arm64: kasan: avoid TLB conflicts
arm64: mm: add code to safely replace TTBR1_EL1
arm64: add function to install the idmap
arm64: unmap idmap earlier
arm64: unify idmap removal
arm64: mm: place empty_zero_page in bss
arm64: mm: specialise pagetable allocators
asm-generic: Fix local variable shadow in __set_fixmap_offset
Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules
arm64: Fix an enum typo in mm/dump.c
arm64: kasan: ensure that the KASAN zero page is mapped read-only
arch/arm64/include/asm/pgtable.h: add pmd_mkclean for THP
arm64: hide __efistub_ aliases from kallsyms
Linux 4.4.10
drm/i915/skl: Fix DMC load on Skylake J0 and K0
lib/test-string_helpers.c: fix and improve string_get_size() tests
ACPI / processor: Request native thermal interrupt handling via _OSC
drm/i915: Fake HDMI live status
drm/i915: Make RPS EI/thresholds multiple of 25 on SNB-BDW
drm/i915: Fix eDP low vswing for Broadwell
drm/i915/ddi: Fix eDP VDD handling during booting and suspend/resume
drm/radeon: make sure vertical front porch is at least 1
iio: ak8975: fix maybe-uninitialized warning
iio: ak8975: Fix NULL pointer exception on early interrupt
drm/amdgpu: set metadata pointer to NULL after freeing.
drm/amdgpu: make sure vertical front porch is at least 1
gpu: ipu-v3: Fix imx-ipuv3-crtc module autoloading
nvmem: mxs-ocotp: fix buffer overflow in read
USB: serial: cp210x: add Straizona Focusers device ids
USB: serial: cp210x: add ID for Link ECU
ata: ahci-platform: Add ports-implemented DT bindings.
libahci: save port map for forced port map
powerpc: Fix bad inline asm constraint in create_zero_mask()
ACPICA: Dispatcher: Update thread ID for recursive method calls
x86/sysfb_efi: Fix valid BAR address range check
ARC: Add missing io barriers to io{read,write}{16,32}be()
ARM: cpuidle: Pass on arm_cpuidle_suspend()'s return value
propogate_mnt: Handle the first propogated copy being a slave
fs/pnode.c: treat zero mnt_group_id-s as unequal
x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO
MAINTAINERS: Remove asterisk from EFI directory names
writeback: Fix performance regression in wb_over_bg_thresh()
batman-adv: Reduce refcnt of removed router when updating route
batman-adv: Fix broadcast/ogm queue limit on a removed interface
batman-adv: Check skb size before using encapsulated ETH+VLAN header
batman-adv: fix DAT candidate selection (must use vid)
mm: update min_free_kbytes from khugepaged after core initialization
proc: prevent accessing /proc/<PID>/environ until it's ready
Input: zforce_ts - fix dual touch recognition
HID: Fix boot delay for Creative SB Omni Surround 5.1 with quirk
HID: wacom: Add support for DTK-1651
xen/evtchn: fix ring resize when binding new events
xen/balloon: Fix crash when ballooning on x86 32 bit PAE
xen: Fix page <-> pfn conversion on 32 bit systems
ARM: SoCFPGA: Fix secondary CPU startup in thumb2 kernel
ARM: EXYNOS: Properly skip unitialized parent clock in power domain on
mm/zswap: provide unique zpool name
mm, cma: prevent nr_isolated_* counters from going negative
Minimal fix-up of bad hashing behavior of hash_64()
MD: make bio mergeable
tracing: Don't display trigger file for events that can't be enabled
mac80211: fix statistics leak if dev_alloc_name() fails
ath9k: ar5008_hw_cmn_spur_mitigate: add missing mask_m & mask_p initialisation
lpfc: fix misleading indentation
clk: qcom: msm8960: Fix ce3_src register offset
clk: versatile: sp810: support reentrance
clk: qcom: msm8960: fix ce3_core clk enable register
clk: meson: Fix meson_clk_register_clks() signature type mismatch
clk: rockchip: free memory in error cases when registering clock branches
soc: rockchip: power-domain: fix err handle while probing
clk-divider: make sure read-only dividers do not write to their register
CNS3xxx: Fix PCI cns3xxx_write_config()
mwifiex: fix corner case association failure
ata: ahci_xgene: dereferencing uninitialized pointer in probe
nbd: ratelimit error msgs after socket close
mfd: intel-lpss: Remove clock tree on error path
ipvs: drop first packet to redirect conntrack
ipvs: correct initial offset of Call-ID header search in SIP persistence engine
ipvs: handle ip_vs_fill_iph_skb_off failure
RDMA/iw_cxgb4: Fix bar2 virt addr calculation for T4 chips
Revert: "powerpc/tm: Check for already reclaimed tasks"
arm64: head.S: use memset to clear BSS
efi: stub: define DISABLE_BRANCH_PROFILING for all architectures
arm64: entry: remove pointless SPSR mode check
arm64: mm: move pgd_cache initialisation to pgtable_cache_init
arm64: module: avoid undefined shift behavior in reloc_data()
arm64: module: fix relocation of movz instruction with negative immediate
arm64: traps: address fallout from printk -> pr_* conversion
arm64: ftrace: fix a stack tracer's output under function graph tracer
arm64: pass a task parameter to unwind_frame()
arm64: ftrace: modify a stack frame in a safe way
arm64: remove irq_count and do_softirq_own_stack()
arm64: hugetlb: add support for PTE contiguous bit
arm64: Use PoU cache instr for I/D coherency
arm64: Defer dcache flush in __cpu_copy_user_page
arm64: reduce stack use in irq_handler
arm64: Documentation: add list of software workarounds for errata
arm64: mm: place __cpu_setup in .text
arm64: cmpxchg: Don't incldue linux/mmdebug.h
arm64: mm: fold alternatives into .init
arm64: Remove redundant padding from linker script
arm64: mm: remove pointless PAGE_MASKing
arm64: don't call C code with el0's fp register
arm64: when walking onto the task stack, check sp & fp are in current->stack
arm64: Add this_cpu_ptr() assembler macro for use in entry.S
arm64: irq: fix walking from irq stack to task stack
arm64: Add do_softirq_own_stack() and enable irq_stacks
arm64: Modify stack trace and dump for use with irq_stack
arm64: Store struct thread_info in sp_el0
arm64: Add trace_hardirqs_off annotation in ret_to_user
arm64: ftrace: fix the comments for ftrace_modify_code
arm64: ftrace: stop using kstop_machine to enable/disable tracing
arm64: spinlock: serialise spin_unlock_wait against concurrent lockers
arm64: enable HAVE_IRQ_TIME_ACCOUNTING
arm64: fix COMPAT_SHMLBA definition for large pages
arm64: add __init/__initdata section marker to some functions/variables
arm64: pgtable: implement pte_accessible()
arm64: mm: allow sections for unaligned bases
arm64: mm: detect bad __create_mapping uses
Linux 4.4.9
extcon: max77843: Use correct size for reading the interrupt register
stm class: Select CONFIG_SRCU
megaraid_sas: add missing curly braces in ioctl handler
sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race
thermal: rockchip: fix a impossible condition caused by the warning
unbreak allmodconfig KCONFIG_ALLCONFIG=...
jme: Fix device PM wakeup API usage
jme: Do not enable NIC WoL functions on S0
bus: imx-weim: Take the 'status' property value into account
ARM: dts: pxa: fix dma engine node to pxa3xx-nand
ARM: dts: armada-375: use armada-370-sata for SATA
ARM: EXYNOS: select THERMAL_OF
ARM: prima2: always enable reset controller
ARM: OMAP3: Add cpuidle parameters table for omap3430
ext4: fix races of writeback with punch hole and zero range
ext4: fix races between buffered IO and collapse / insert range
ext4: move unlocked dio protection from ext4_alloc_file_blocks()
ext4: fix races between page faults and hole punching
perf stat: Document --detailed option
perf tools: handle spaces in file names obtained from /proc/pid/maps
perf hists browser: Only offer symbol scripting when a symbol is under the cursor
mtd: nand: Drop mtd.owner requirement in nand_scan
mtd: brcmnand: Fix v7.1 register offsets
mtd: spi-nor: remove micron_quad_enable()
serial: sh-sci: Remove cpufreq notifier to fix crash/deadlock
ext4: fix NULL pointer dereference in ext4_mark_inode_dirty()
x86/mm/kmmio: Fix mmiotrace for hugepages
perf evlist: Reference count the cpu and thread maps at set_maps()
drivers/misc/ad525x_dpot: AD5274 fix RDAC read back errors
rtc: max77686: Properly handle regmap_irq_get_virq() error code
rtc: rx8025: remove rv8803 id
rtc: ds1685: passing bogus values to irq_restore
rtc: vr41xx: Wire up alarm_irq_enable
rtc: hym8563: fix invalid year calculation
PM / Domains: Fix removal of a subdomain
PM / OPP: Initialize u_volt_min/max to a valid value
misc: mic/scif: fix wrap around tests
misc/bmp085: Enable building as a module
lib/mpi: Endianness fix
fbdev: da8xx-fb: fix videomodes of lcd panels
scsi_dh: force modular build if SCSI is a module
paride: make 'verbose' parameter an 'int' again
regulator: s5m8767: fix get_register() error handling
irqchip/mxs: Fix error check of of_io_request_and_map()
irqchip/sunxi-nmi: Fix error check of of_io_request_and_map()
spi/rockchip: Make sure spi clk is on in rockchip_spi_set_cs
locking/mcs: Fix mcs_spin_lock() ordering
regulator: core: Fix nested locking of supplies
regulator: core: Ensure we lock all regulators
regulator: core: fix regulator_lock_supply regression
Revert "regulator: core: Fix nested locking of supplies"
videobuf2-v4l2: Verify planes array in buffer dequeueing
videobuf2-core: Check user space planes array in dqbuf
USB: usbip: fix potential out-of-bounds write
cgroup: make sure a parent css isn't freed before its children
mm/hwpoison: fix wrong num_poisoned_pages accounting
mm: vmscan: reclaim highmem zone if buffer_heads is over limit
numa: fix /proc/<pid>/numa_maps for THP
mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check
memcg: relocate charge moving from ->attach to ->post_attach
cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
slub: clean up code for kmem cgroup support to kmem_cache_free_bulk
workqueue: fix ghost PENDING flag while doing MQ IO
x86/apic: Handle zero vector gracefully in clear_vector_irq()
efi: Expose non-blocking set_variable() wrapper to efivars
efi: Fix out-of-bounds read in variable_matches()
IB/security: Restrict use of the write() interface
IB/mlx5: Expose correct max_sge_rd limit
cxl: Keep IRQ mappings on context teardown
v4l2-dv-timings.h: fix polarity for 4k formats
vb2-memops: Fix over allocation of frame vectors
ASoC: rt5640: Correct the digital interface data select
ASoC: dapm: Make sure we have a card when displaying component widgets
ASoC: ssm4567: Reset device before regcache_sync()
ASoC: s3c24xx: use const snd_soc_component_driver pointer
EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback
toshiba_acpi: Fix regression caused by hotkey enabling value
i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared
i2c: cpm: Fix build break due to incompatible pointer types
perf intel-pt: Fix segfault tracing transactions
drm/i915: Use fw_domains_put_with_fifo() on HSW
drm/i915: Fixup the free space logic in ring_prepare
drm/amdkfd: uninitialized variable in dbgdev_wave_control_set_registers()
drm/i915: skl_update_scaler() wants a rotation bitmask instead of bit number
drm/i915: Cleanup phys status page too
pwm: brcmstb: Fix check of devm_ioremap_resource() return code
drm/dp/mst: Get validated port ref in drm_dp_update_payload_part1()
drm/dp/mst: Restore primary hub guid on resume
drm/dp/mst: Validate port in drm_dp_payload_send_msg()
drm/nouveau/gr/gf100: select a stream master to fixup tfb offset queries
drm: Loongson-3 doesn't fully support wc memory
drm/radeon: fix vertical bars appear on monitor (v2)
drm/radeon: forbid mapping of userptr bo through radeon device file
drm/radeon: fix initial connector audio value
drm/radeon: add a quirk for a XFX R9 270X
drm/amdgpu: fix regression on CIK (v2)
amdgpu/uvd: add uvd fw version for amdgpu
drm/amdgpu: bump the afmt limit for CZ, ST, Polaris
drm/amdgpu: use defines for CRTCs and AMFT blocks
drm/amdgpu: when suspending, if uvd/vce was running. need to cancel delay work.
iommu/dma: Restore scatterlist offsets correctly
iommu/amd: Fix checking of pci dma aliases
pinctrl: single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs
pinctrl: mediatek: correct debounce time unit in mtk_gpio_set_debounce
xen kconfig: don't "select INPUT_XEN_KBDDEV_FRONTEND"
Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay
Input: gtco - fix crash on detecting device without endpoints
netlink: don't send NETLINK_URELEASE for unbound sockets
nl80211: check netlink protocol in socket release notification
powerpc: Update TM user feature bits in scan_features()
powerpc: Update cpu_user_features2 in scan_features()
powerpc: scan_features() updates incorrect bits for REAL_LE
crypto: talitos - fix AEAD tcrypt tests
crypto: talitos - fix crash in talitos_cra_init()
crypto: sha1-mb - use corrcet pointer while completing jobs
crypto: ccp - Prevent information leakage on export
iwlwifi: mvm: fix memory leak in paging
iwlwifi: pcie: lower the debug level for RSA semaphore access
s390/pci: add extra padding to function measurement block
cpufreq: intel_pstate: Fix processing for turbo activation ratio
Revert "drm/amdgpu: disable runtime pm on PX laptops without dGPU power control"
Revert "drm/radeon: disable runtime pm on PX laptops without dGPU power control"
drm/i915: Fix race condition in intel_dp_destroy_mst_connector()
drm/qxl: fix cursor position with non-zero hotspot
drm/nouveau/core: use vzalloc for allocating ramht
futex: Acknowledge a new waiter in counter before plist
futex: Handle unlock_pi race gracefully
asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic()
ALSA: hda - Add dock support for ThinkPad X260
ALSA: pcxhr: Fix missing mutex unlock
ALSA: hda - add PCI ID for Intel Broxton-T
ALSA: hda - Keep powering up ADCs on Cirrus codecs
ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m
ALSA: hda - Don't trust the reported actual power state
x86 EDAC, sb_edac.c: Repair damage introduced when "fixing" channel address
x86/mm/xen: Suppress hugetlbfs in PV guests
arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission
arm64: Honour !PTE_WRITE in set_pte_at() for kernel mappings
sched/cgroup: Fix/cleanup cgroup teardown/init
dmaengine: pxa_dma: fix the maximum requestor line
dmaengine: hsu: correct use of channel status register
dmaengine: dw: fix master selection
debugfs: Make automount point inodes permanently empty
lib: lz4: fixed zram with lz4 on big endian machines
dm cache metadata: fix cmd_read_lock() acquiring write lock
dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros
usb: gadget: f_fs: Fix use-after-free
usb: hcd: out of bounds access in for_each_companion
xhci: fix 10 second timeout on removal of PCI hotpluggable xhci controllers
usb: xhci: fix wild pointers in xhci_mem_cleanup
xhci: resume USB 3 roothub first
usb: xhci: applying XHCI_PME_STUCK_QUIRK to Intel BXT B0 host
assoc_array: don't call compare_object() on a node
ARM: OMAP2+: hwmod: Fix updating of sysconfig register
ARM: OMAP2: Fix up interconnect barrier initialization for DRA7
ARM: mvebu: Correct unit address for linksys
ARM: dts: AM43x-epos: Fix clk parent for synctimer
KVM: arm/arm64: Handle forward time correction gracefully
kvm: x86: do not leak guest xcr0 into host interrupt handlers
x86/mce: Avoid using object after free in genpool
block: loop: fix filesystem corruption in case of aio/dio
block: partition: initialize percpuref before sending out KOBJ_ADD
Conflicts:
arch/arm64/Kconfig
arch/arm64/include/asm/cputype.h
arch/arm64/include/asm/hardirq.h
arch/arm64/include/asm/irq.h
arch/arm64/kernel/cpu_errata.c
arch/arm64/kernel/cpuinfo.c
arch/arm64/kernel/setup.c
arch/arm64/kernel/smp.c
arch/arm64/kernel/stacktrace.c
arch/arm64/mm/init.c
arch/arm64/mm/mmu.c
arch/arm64/mm/pageattr.c
mm/memcontrol.c
CRs-Fixed: 1054234
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
Change-Id: I2a7a34631ffee36ce18b9171f16d023be777392f
commit 920c720aa5aa3900a7f1689228fdfc2580a91e7e upstream.
Similar to commit b4b29f9485 ("locking/osq: Fix ordering of node
initialisation in osq_lock") the use of xchg_acquire() is
fundamentally broken with MCS like constructs.
Furthermore, it turns out we rely on the global transitivity of this
operation because the unlock path observes the pointer with a
READ_ONCE(), not an smp_load_acquire().
This is non-critical because the MCS code isn't actually used and
mostly serves as documentation, a stepping stone to the more complex
things we've build on top of the idea.
Reported-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: 3552a07a9c ("locking/mcs: Use acquire/release semantics")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently dump_stack is printed once a spin_bug is detected for rwlock.
So provide an options to trigger a panic or watchdog bite for debugging
rwlock magic corruptions and lockups.
Change-Id: I20807e8eceb8b81635e58701d1f9f9bd36ab5877
[abhimany: replace msm with qcom]
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>
Currently we cause a BUG_ON once a spin_bug is detected, but
that causes a whole lot of processing and the other CPUs would
have proceeded to perform other actions and the state of the system
is moved by the time we can analyze it.
Provide an option to trigger a watchdog bite instead so that we
can get the traces as close to the issue as possible.
Change-Id: Ic8d692ebd02c6940a3b4e5798463744db20b0026
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Once a spinlock lockup is detected on a CPU, we invoke a Kernel Panic.
During the panic handling, we might see more instances of spinlock
lockup from other CPUs. This causes the dmesg to be cluttered and makes
it cumbersome to detect what exactly happened.
Call spin_bug instead of calling spin_dump directly.
Change-Id: I57857a991345a8dac3cd952463d05129145867a8
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Data corruptions in the kernel often end up in system crashes that
are easier to debug closer to the time of detection. Specifically,
if we do not panic immediately after lock or list corruptions have been
detected, the problem context is lost in the ensuing system mayhem.
Add support for allowing system crash immediately after such corruptions
are detected. The CONFIG option controls the enabling/disabling of the
feature.
Change-Id: I9b2eb62da506a13007acff63e85e9515145909ff
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
[abhimany: minor merge conflict resolution]
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>
The Cavium guys reported a soft lockup on their arm64 machine, caused by
commit c55a6ffa62 ("locking/osq: Relax atomic semantics"):
mutex_optimistic_spin+0x9c/0x1d0
__mutex_lock_slowpath+0x44/0x158
mutex_lock+0x54/0x58
kernfs_iop_permission+0x38/0x70
__inode_permission+0x88/0xd8
inode_permission+0x30/0x6c
link_path_walk+0x68/0x4d4
path_openat+0xb4/0x2bc
do_filp_open+0x74/0xd0
do_sys_open+0x14c/0x228
SyS_openat+0x3c/0x48
el0_svc_naked+0x24/0x28
This is because in osq_lock we initialise the node for the current CPU:
node->locked = 0;
node->next = NULL;
node->cpu = curr;
and then publish the current CPU in the lock tail:
old = atomic_xchg_acquire(&lock->tail, curr);
Once the update to lock->tail is visible to another CPU, the node is
then live and can be both read and updated by concurrent lockers.
Unfortunately, the ACQUIRE semantics of the xchg operation mean that
there is no guarantee the contents of the node will be visible before
lock tail is updated. This can lead to lock corruption when, for
example, a concurrent locker races to set the next field.
Fixes: c55a6ffa62 ("locking/osq: Relax atomic semantics"):
Reported-by: David Daney <ddaney@caviumnetworks.com>
Reported-by: Andrew Pinski <andrew.pinski@caviumnetworks.com>
Tested-by: Andrew Pinski <andrew.pinski@caviumnetworks.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1449856001-21177-1-git-send-email-will.deacon@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There were still a number of references to my old Red Hat email
address in the kernel source. Remove these while keeping the
Red Hat copyright notices intact.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull scheduler changes from Ingo Molnar:
"The main changes in this cycle were:
- sched/fair load tracking fixes and cleanups (Byungchul Park)
- Make load tracking frequency scale invariant (Dietmar Eggemann)
- sched/deadline updates (Juri Lelli)
- stop machine fixes, cleanups and enhancements for bugs triggered by
CPU hotplug stress testing (Oleg Nesterov)
- scheduler preemption code rework: remove PREEMPT_ACTIVE and related
cleanups (Peter Zijlstra)
- Rework the sched_info::run_delay code to fix races (Peter Zijlstra)
- Optimize per entity utilization tracking (Peter Zijlstra)
- ... misc other fixes, cleanups and smaller updates"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
sched: Start stopper early
stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
sched/x86: Fix typo in __switch_to() comments
sched/core: Remove a parameter in the migrate_task_rq() function
sched/core: Drop unlikely behind BUG_ON()
sched/core: Fix task and run queue sched_info::run_delay inconsistencies
sched/numa: Fix task_tick_fair() from disabling numa_balancing
sched/core: Add preempt_count invariant check
sched/core: More notrace annotations
sched/core: Kill PREEMPT_ACTIVE
sched/core, sched/x86: Kill thread_info::saved_preempt_count
sched/core: Simplify preempt_count tests
sched/core: Robustify preemption leak checks
sched/core: Stop setting PREEMPT_ACTIVE
...
Pull locking changes from Ingo Molnar:
"The main changes in this cycle were:
- More gradual enhancements to atomic ops: new atomic*_read_ctrl()
ops, synchronize atomic_{read,set}() ordering requirements between
architectures, add atomic_long_t bitops. (Peter Zijlstra)
- Add _{relaxed|acquire|release}() variants for inc/dec atomics and
use them in various locking primitives: mutex, rtmutex, mcs, rwsem.
This enables weakly ordered architectures (such as arm64) to make
use of more locking related optimizations. (Davidlohr Bueso)
- Implement atomic[64]_{inc,dec}_relaxed() on ARM. (Will Deacon)
- Futex kernel data cache footprint micro-optimization. (Rasmus
Villemoes)
- pvqspinlock runtime overhead micro-optimization. (Waiman Long)
- misc smaller fixlets"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ARM, locking/atomics: Implement _relaxed variants of atomic[64]_{inc,dec}
locking/rwsem: Use acquire/release semantics
locking/mcs: Use acquire/release semantics
locking/rtmutex: Use acquire/release semantics
locking/mutex: Use acquire/release semantics
locking/asm-generic: Add _{relaxed|acquire|release}() variants for inc/dec atomics
atomic: Implement atomic_read_ctrl()
atomic, arch: Audit atomic_{read,set}()
atomic: Add atomic_long_t bitops
futex: Force hot variables into a single cache line
locking/pvqspinlock: Kick the PV CPU unconditionally when _Q_SLOW_VAL
locking/osq: Relax atomic semantics
locking/qrwlock: Rename ->lock to ->wait_lock
locking/Documentation/lockstat: Fix typo - lokcing -> locking
locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h
Pull RCU updates from Paul E. McKenney:
- Miscellaneous fixes. (Paul E. McKenney, Boqun Feng, Oleg Nesterov, Patrick Marlier)
- Improvements to expedited grace periods. (Paul E. McKenney)
- Performance improvements to and locktorture tests for percpu-rwsem.
(Oleg Nesterov, Paul E. McKenney)
- Torture-test changes. (Paul E. McKenney, Davidlohr Bueso)
- Documentation updates. (Paul E. McKenney)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The locktorture module has a list of torture types, and specifying
a type not on this list is supposed to cleanly fail the module load.
Unfortunately, the "fail" happens without the "cleanly". This commit
therefore adds the needed clean-up after an incorrect torture_type.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Based on Peter Zijlstra's earlier patch.
Change percpu_down_read() to use __down_read(), this way we can
do rwsem_acquire_read() unconditionally at the start to make this
code more symmetric and clean.
Originally-From: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Update the comments broken by the previous change.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Currently down_write/up_write calls synchronize_sched_expedited()
twice, which is evil. Change this code to rely on rcu-sync primitives.
This avoids the _expedited "big hammer", and this can be faster in
the contended case or even in the case when a single thread does
down_write/up_write in a loop.
Of course, a single down_write() will take more time, but otoh it
will be much more friendly to the whole system.
To simplify the review this patch doesn't update the comments, fixed
by the next change.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This is the temporary ugly hack which will be reverted later. We only
need it to ensure that the next patch will not break "change sb_writers
to use percpu_rw_semaphore" patches routed via the VFS tree.
The alloc_super()->destroy_super() error path assumes that it is safe
to call percpu_free_rwsem() after kzalloc() without percpu_init_rwsem(),
so let's not disappoint it.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit adds percpu_rwsem tests based on the earlier rwsem tests.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit exports percpu_down_read(), percpu_down_write(),
__percpu_init_rwsem(), percpu_up_read(), and percpu_up_write() to allow
locktorture to test them when built as a module.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Real time mutexes is one of the few general primitives
that we do not have in locktorture. Address this -- a few
considerations:
o To spice things up, enable competing thread(s) to become
rt, such that we can stress different prio boosting paths
in the rtmutex code. Introduce a ->task_boost callback,
only used by rtmutex-torturer. Tasks will boost/deboost
around every 50k (arbitrarily) lock/unlock operations.
o Hold times are similar to what we have for other locks:
only occasionally having longer hold times (per ~200k ops).
So we roughly do two full rt boost+deboosting ops with
short hold times.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
As of 654672d4ba (locking/atomics: Add _{acquire|release|relaxed}()
variants of some atomic operations) and 6d79ef2d30 (locking, asm-generic:
Add _{relaxed|acquire|release}() variants for 'atomic_long_t'), weakly
ordered archs can benefit from more relaxed use of barriers when locking
and unlocking, instead of regular full barrier semantics. While currently
only arm64 supports such optimizations, updating corresponding locking
primitives serves for other archs to immediately benefit as well, once the
necessary machinery is implemented of course.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E.McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443643395-17016-6-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As of 654672d4ba (locking/atomics: Add _{acquire|release|relaxed}()
variants of some atomic operations) and 6d79ef2d30 (locking, asm-generic:
Add _{relaxed|acquire|release}() variants for 'atomic_long_t'), weakly
ordered archs can benefit from more relaxed use of barriers when locking
and unlocking, instead of regular full barrier semantics. While currently
only arm64 supports such optimizations, updating corresponding locking
primitives serves for other archs to immediately benefit as well, once the
necessary machinery is implemented of course.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E.McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443643395-17016-5-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As of 654672d4ba (locking/atomics: Add _{acquire|release|relaxed}()
variants of some atomic operations) and 6d79ef2d30 (locking, asm-generic:
Add _{relaxed|acquire|release}() variants for 'atomic_long_t'), weakly
ordered archs can benefit from more relaxed use of barriers when locking
and unlocking, instead of regular full barrier semantics. While currently
only arm64 supports such optimizations, updating corresponding locking
primitives serves for other archs to immediately benefit as well, once the
necessary machinery is implemented of course.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E.McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443643395-17016-4-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As of 654672d4ba (locking/atomics: Add _{acquire|release|relaxed}()
variants of some atomic operations) and 6d79ef2d30 (locking, asm-generic:
Add _{relaxed|acquire|release}() variants for 'atomic_long_t'), weakly
ordered archs can benefit from more relaxed use of barriers when locking
and unlocking, instead of regular full barrier semantics. While currently
only arm64 supports such optimizations, updating corresponding locking
primitives serves for other archs to immediately benefit as well, once the
necessary machinery is implemented of course.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E.McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443643395-17016-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
rt_mutex_waiter_less() check of task deadlines is open coded. Since this
is subject to wraparound bugs, make it use the correct helper.
Reported-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441188096-23021-4-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Various people reported hitting the "unpinning an unpinned lock"
warning. As it turns out there are 2 places where we take a lock out
of the middle of a stack, and in those cases it would fail to preserve
the pin_count when rebuilding the lock stack.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reported-by: Tim Spriggs <tspriggs@apple.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davej@codemonkey.org.uk
Link: http://lkml.kernel.org/r/20150916141040.GA11639@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If _Q_SLOW_VAL has been set, the vCPU state must have been vcpu_hashed.
The extra check at the end of __pv_queued_spin_unlock() is unnecessary
and can be removed.
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441996658-62854-3-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
... by using acquire/release for ops around the lock->tail. As such,
weakly ordered archs can benefit from more relaxed use of barriers
when issuing atomics.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/1442216244-4409-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
... trivial, but reads a little nicer when we name our
actual primitive 'lock'.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/1442216244-4409-1-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull locking fixes from Ingo Molnar:
"Spinlock performance regression fix, plus documentation fixes"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/static_keys: Fix up the static keys documentation
locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support
locking/qspinlock/x86: Fix performance regression under unaccelerated VMs
locking/static_keys: Fix a silly typo
Dave ran into horrible performance on a VM without PARAVIRT_SPINLOCKS
set and Linus noted that the test-and-set implementation was retarded.
One should spin on the variable with a load, not a RMW.
While there, remove 'queued' from the name, as the lock isn't queued
at all, but a simple test-and-set.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Dave Chinner <david@fromorbit.com>
Tested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lkml.kernel.org/r/20150904152523.GR18673@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull vfs updates from Al Viro:
"In this one:
- d_move fixes (Eric Biederman)
- UFS fixes (me; locking is mostly sane now, a bunch of bugs in error
handling ought to be fixed)
- switch of sb_writers to percpu rwsem (Oleg Nesterov)
- superblock scalability (Josef Bacik and Dave Chinner)
- swapon(2) race fix (Hugh Dickins)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits)
vfs: Test for and handle paths that are unreachable from their mnt_root
dcache: Reduce the scope of i_lock in d_splice_alias
dcache: Handle escaped paths in prepend_path
mm: fix potential data race in SyS_swapon
inode: don't softlockup when evicting inodes
inode: rename i_wb_list to i_io_list
sync: serialise per-superblock sync operations
inode: convert inode_sb_list_lock to per-sb
inode: add hlist_fake to avoid the inode hash lock in evict
writeback: plug writeback at a high level
change sb_writers to use percpu_rw_semaphore
shift percpu_counter_destroy() into destroy_super_work()
percpu-rwsem: kill CONFIG_PERCPU_RWSEM
percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()
percpu-rwsem: introduce percpu_down_read_trylock()
document rwsem_release() in sb_wait_write()
fix the broken lockdep logic in __sb_start_write()
introduce __sb_writers_{acquired,release}() helpers
ufs_inode_get{frag,block}(): get rid of 'phys' argument
ufs_getfrag_block(): tidy up a bit
...
The qrwlock implementation is slightly heavy in its use of memory
barriers, mainly through the use of _cmpxchg() and _return() atomics, which
imply full barrier semantics.
This patch modifies the qrwlock code to use the more relaxed atomic
routines so that we can reduce the unnecessary barrier overhead on
weakly-ordered architectures.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hp.com
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1438880084-18856-7-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For an over-committed guest with more vCPUs than physical CPUs
available, it is possible that a vCPU may be kicked twice before
getting the lock - once before it becomes queue head and once again
before it gets the lock. All these CPU kicking and halting (VMEXIT)
can be expensive and slow down system performance.
This patch adds a new vCPU state (vcpu_hashed) which enables the code
to delay CPU kicking until at unlock time. Once this state is set,
the new lock holder will set _Q_SLOW_VAL and fill in the hash table
on behalf of the halted queue head vCPU. The original vcpu_halted
state will be used by pv_wait_node() only to differentiate other
queue nodes from the qeue head.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1436647018-49734-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, a reader will check first to make sure that the writer mode
byte is cleared before incrementing the reader count. That waiting is
not really necessary. It increases the latency in the reader/writer
to reader transition and reduces readers performance.
This patch eliminates that waiting. It also has the side effect
of reducing the chance of writer lock stealing and improving the
fairness of the lock. Using a locking microbenchmark, a 10-threads 5M
locking loop of mostly readers (RW ratio = 10,000:1) has the following
performance numbers in a Haswell-EX box:
Kernel Locking Rate (Kops/s)
------ ---------------------
4.1.1 15,063,081
4.1.1+patch 17,241,552 (+14.4%)
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1436459543-29126-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When we unlock in __pv_queued_spin_unlock(), a failed cmpxchg() on the lock
value indicates that we need to take the slow-path and unhash the
corresponding node blocked on the lock.
Since a failed cmpxchg() does not provide any memory-ordering guarantees,
it is possible that the node data could be read before the cmpxchg() on
weakly-ordered architectures and therefore return a stale value, leading
to hash corruption and/or a BUG().
This patch adds an smb_rmb() following the failed cmpxchg operation, so
that the unhashing is ordered after the lock has been checked.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[ Added more comments]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <Waiman.Long@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steve Capper <Steve.Capper@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150713155830.GL2632@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Rename the on-stack variable to match the datastructure variable,
- place the cmpxchg back under the comment that explains it,
- clean up the WARN() statement to avoid superfluous conditionals
and line-breaks.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Enabling locking-selftest in a VM guest may cause the following
kernel panic:
kernel BUG at .../kernel/locking/qspinlock_paravirt.h:137!
This is due to the fact that the pvqspinlock unlock function is
expecting either a _Q_LOCKED_VAL or _Q_SLOW_VAL in the lock
byte. This patch prevents that bug report by ignoring it when
debug_locks_silent is set. Otherwise, a warning will be printed
if it contains an unexpected value.
With this patch applied, the kernel locking-selftest completed
without any noise.
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1436663959-53092-1-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
No one uses this anymore, and this is not the first time the
idea of replacing it with a (now possible) userspace side.
Lock stealing logic was removed long ago in when the lock
was granted to the highest prio.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1435782588-4177-2-git-send-email-dave@stgolabs.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The qrwlock is fair in the process context, but becoming unfair when
in the interrupt context to support use cases like the tasklist_lock.
The current code isn't that well-documented on what happens when
in the interrupt context. The rspin_until_writer_unlock() will only
spin if the writer has gotten the lock. If the writer is still in the
waiting state, the increment in the reader count will cause the writer
to remain in the waiting state and the new interrupt context reader
will get the lock and return immediately. The current code, however,
does an additional read of the lock value which is not necessary as
the information has already been there in the fast path. This may
sometime cause an additional cacheline transfer when the lock is
highly contended.
This patch passes the lock value information gotten in the fast path
to the slow path to eliminate the additional read. It also documents
the action for the interrupt context readers more clearly.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1434729002-57724-3-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
