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* Merge android-4.4.178 (7af10f2) into msm-4.4Srinivasarao P2019-04-05
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-7af10f2 Linux 4.4.178 stm class: Hide STM-specific options if STM is disabled coresight: removing bind/unbind options from sysfs arm64: support keyctl() system call in 32-bit mode Revert "USB: core: only clean up what we allocated" xhci: Fix port resume done detection for SS ports with LPM enabled KVM: Reject device ioctls from processes other than the VM's creator x86/smp: Enforce CONFIG_HOTPLUG_CPU when SMP=y perf intel-pt: Fix TSC slip gpio: adnp: Fix testing wrong value in adnp_gpio_direction_input fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc USB: serial: option: add Olicard 600 USB: serial: option: set driver_info for SIM5218 and compatibles USB: serial: mos7720: fix mos_parport refcount imbalance on error path USB: serial: ftdi_sio: add additional NovaTech products USB: serial: cp210x: add new device id serial: sh-sci: Fix setting SCSCR_TIE while transferring data serial: max310x: Fix to avoid potential NULL pointer dereference staging: vt6655: Fix interrupt race condition on device start up. staging: vt6655: Remove vif check from vnt_interrupt tty: atmel_serial: fix a potential NULL pointer dereference scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices scsi: zfcp: fix rport unblock if deleted SCSI devices on Scsi_Host scsi: sd: Fix a race between closing an sd device and sd I/O ALSA: pcm: Don't suspend stream in unrecoverable PCM state ALSA: pcm: Fix possible OOB access in PCM oss plugins ALSA: seq: oss: Fix Spectre v1 vulnerability ALSA: rawmidi: Fix potential Spectre v1 vulnerability ALSA: compress: add support for 32bit calls in a 64bit kernel ARM: imx6q: cpuidle: fix bug that CPU might not wake up at expected time btrfs: raid56: properly unmap parity page in finish_parity_scrub() btrfs: remove WARN_ON in log_dir_items mac8390: Fix mmio access size probe sctp: get sctphdr by offset in sctp_compute_cksum vxlan: Don't call gro_cells_destroy() before device is unregistered tcp: do not use ipv6 header for ipv4 flow packets: Always register packet sk in the same order Add hlist_add_tail_rcu() (Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net) net: rose: fix a possible stack overflow net/packet: Set __GFP_NOWARN upon allocation in alloc_pg_vec mISDN: hfcpci: Test both vendor & device ID for Digium HFC4S dccp: do not use ipv6 header for ipv4 flow stmmac: copy unicast mac address to MAC registers cfg80211: size various nl80211 messages correctly mmc: mmc: fix switch timeout issue caused by jiffies precision arm64: kconfig: drop CONFIG_RTC_LIB dependency video: fbdev: Set pixclock = 0 in goldfishfb cpu/hotplug: Handle unbalanced hotplug enable/disable usb: gadget: rndis: free response queue during REMOTE_NDIS_RESET_MSG usb: gadget: configfs: add mutex lock before unregister gadget ipv6: fix endianness error in icmpv6_err stm class: Fix stm device initialization order stm class: Do not leak the chrdev in error path PM / Hibernate: Call flush_icache_range() on pages restored in-place arm64: kernel: Include _AC definition in page.h perf/ring_buffer: Refuse to begin AUX transaction after rb->aux_mmap_count drops mac80211: fix "warning: ‘target_metric’ may be used uninitialized" arm64/kernel: fix incorrect EL0 check in inv_entry macro ARM: 8510/1: rework ARM_CPU_SUSPEND dependencies staging: goldfish: audio: fix compiliation on arm staging: ion: Set minimum carveout heap allocation order to PAGE_SHIFT staging: ashmem: Add missing include staging: ashmem: Avoid deadlock with mmap/shrink asm-generic: Fix local variable shadow in __set_fixmap_offset coresight: etm4x: Check every parameter used by dma_xx_coherent. coresight: "DEVICE_ATTR_RO" should defined as static. stm class: Fix a race in unlinking stm class: Fix unbalanced module/device refcounting stm class: Guard output assignment against concurrency stm class: Fix unlocking braino in the error path stm class: Support devices with multiple instances stm class: Prevent user-controllable allocations stm class: Fix link list locking stm class: Fix locking in unbinding policy path coresight: remove csdev's link from topology coresight: release reference taken by 'bus_find_device()' coresight: coresight_unregister() function cleanup coresight: fixing lockdep error writeback: initialize inode members that track writeback history Revert "mmc: block: don't use parameter prefix if built as module" net: diag: support v4mapped sockets in inet_diag_find_one_icsk() perf: Synchronously free aux pages in case of allocation failure arm64: hide __efistub_ aliases from kallsyms hid-sensor-hub.c: fix wrong do_div() usage vmstat: make vmstat_updater deferrable again and shut down on idle android: unconditionally remove callbacks in sync_fence_free() ARM: 8494/1: mm: Enable PXN when running non-LPAE kernel on LPAE processor ARM: 8458/1: bL_switcher: add GIC dependency efi: stub: define DISABLE_BRANCH_PROFILING for all architectures arm64: fix COMPAT_SHMLBA definition for large pages mmc: block: Allow more than 8 partitions per card sched/fair: Fix new task's load avg removed from source CPU in wake_up_new_task() Bluetooth: Verify that l2cap_get_conf_opt provides large enough buffer Bluetooth: Check L2CAP option sizes returned from l2cap_get_conf_opt ath10k: avoid possible string overflow rtc: Fix overflow when converting time64_t to rtc_time USB: core: only clean up what we allocated lib/int_sqrt: optimize small argument serial: sprd: clear timeout interrupt only rather than all interrupts usb: renesas_usbhs: gadget: fix unused-but-set-variable warning arm64: traps: disable irq in die() Hang/soft lockup in d_invalidate with simultaneous calls serial: sprd: adjust TIMEOUT to a big value tcp/dccp: drop SYN packets if accept queue is full usb: gadget: Add the gserial port checking in gs_start_tx() usb: gadget: composite: fix dereference after null check coverify warning kbuild: setlocalversion: print error to STDERR extcon: usb-gpio: Don't miss event during suspend/resume mm/rmap: replace BUG_ON(anon_vma->degree) with VM_WARN_ON mmc: core: fix using wrong io voltage if mmc_select_hs200 fails arm64: mm: Add trace_irqflags annotations to do_debug_exception() usb: dwc3: gadget: Fix suspend/resume during device mode mmc: core: shut up "voltage-ranges unspecified" pr_info() mmc: sanitize 'bus width' in debug output mmc: make MAN_BKOPS_EN message a debug mmc: debugfs: Add a restriction to mmc debugfs clock setting mmc: pwrseq_simple: Make reset-gpios optional to match doc ALSA: hda - Enforces runtime_resume after S3 and S4 for each codec ALSA: hda - Record the current power state before suspend/resume calls locking/lockdep: Add debug_locks check in __lock_downgrade() media: v4l2-ctrls.c/uvc: zero v4l2_event mmc: tmio_mmc_core: don't claim spurious interrupts ext4: brelse all indirect buffer in ext4_ind_remove_space() ext4: fix data corruption caused by unaligned direct AIO ext4: fix NULL pointer dereference while journal is aborted futex: Ensure that futex address is aligned in handle_futex_death() MIPS: Fix kernel crash for R6 in jump label branch function mips: loongson64: lemote-2f: Add IRQF_NO_SUSPEND to "cascade" irqaction. udf: Fix crash on IO error during truncate drm/vmwgfx: Don't double-free the mode stored in par->set_mode mmc: pxamci: fix enum type confusion ANDROID: drop CONFIG_INPUT_KEYCHORD from cuttlefish and ranchu UPSTREAM: virt_wifi: Remove REGULATORY_WIPHY_SELF_MANAGED UPSTREAM: net: socket: set sock->sk to NULL after calling proto_ops::release() f2fs: set pin_file under CAP_SYS_ADMIN f2fs: fix to avoid deadlock in f2fs_read_inline_dir() f2fs: fix to adapt small inline xattr space in __find_inline_xattr() f2fs: fix to do sanity check with inode.i_inline_xattr_size f2fs: give some messages for inline_xattr_size f2fs: don't trigger read IO for beyond EOF page f2fs: fix to add refcount once page is tagged PG_private f2fs: remove wrong comment in f2fs_invalidate_page() f2fs: fix to use kvfree instead of kzfree f2fs: print more parameters in trace_f2fs_map_blocks f2fs: trace f2fs_ioc_shutdown f2fs: fix to avoid deadlock of atomic file operations f2fs: fix to dirty inode for i_mode recovery f2fs: give random value to i_generation f2fs: no need to take page lock in readdir f2fs: fix to update iostat correctly in IPU path f2fs: fix encrypted page memory leak f2fs: make fault injection covering __submit_flush_wait() f2fs: fix to retry fill_super only if recovery failed f2fs: silence VM_WARN_ON_ONCE in mempool_alloc f2fs: correct spelling mistake f2fs: fix wrong #endif f2fs: don't clear CP_QUOTA_NEED_FSCK_FLAG f2fs: don't allow negative ->write_io_size_bits f2fs: fix to check inline_xattr_size boundary correctly Revert "f2fs: fix to avoid deadlock of atomic file operations" Revert "f2fs: fix to check inline_xattr_size boundary correctly" f2fs: do not use mutex lock in atomic context f2fs: fix potential data inconsistence of checkpoint f2fs: fix to avoid deadlock of atomic file operations f2fs: fix to check inline_xattr_size boundary correctly f2fs: jump to label 'free_node_inode' when failing from d_make_root() f2fs: fix to document inline_xattr_size option f2fs: fix to data block override node segment by mistake f2fs: fix typos in code comments f2fs: sync filesystem after roll-forward recovery fs: export evict_inodes f2fs: flush quota blocks after turnning it off f2fs: avoid null pointer exception in dcc_info f2fs: don't wake up too frequently, if there is lots of IOs f2fs: try to keep CP_TRIMMED_FLAG after successful umount f2fs: add quick mode of checkpoint=disable for QA f2fs: run discard jobs when put_super f2fs: fix to set sbi dirty correctly f2fs: UBSAN: set boolean value iostat_enable correctly f2fs: add brackets for macros f2fs: check if file namelen exceeds max value f2fs: fix to trigger fsck if dirent.name_len is zero f2fs: no need to check return value of debugfs_create functions f2fs: export FS_NOCOW_FL flag to user f2fs: check inject_rate validity during configuring f2fs: remove set but not used variable 'err' f2fs: fix compile warnings: 'struct *' declared inside parameter list f2fs: change error code to -ENOMEM from -EINVAL Conflicts: arch/arm/Kconfig arch/arm64/kernel/traps.c drivers/hwtracing/coresight/coresight-etm4x.c drivers/hwtracing/coresight/coresight-tmc.c drivers/hwtracing/stm/Kconfig drivers/hwtracing/stm/core.c drivers/mmc/core/mmc.c drivers/usb/gadget/function/u_serial.c kernel/events/ring_buffer.c net/wireless/nl80211.c sound/core/compress_offload.c Change-Id: I33783dbd0a25d678d6c61204f9e67690e57bed8f Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
| * mm/rmap: replace BUG_ON(anon_vma->degree) with VM_WARN_ONKonstantin Khlebnikov2019-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e4c5800a3991f0c6a766983535dfc10d51802cf6 upstream. This check effectively catches anon vma hierarchy inconsistence and some vma corruptions. It was effective for catching corner cases in anon vma reusing logic. For now this code seems stable so check could be hidden under CONFIG_DEBUG_VM and replaced with WARN because it's not so fatal. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Vasily Averin <vvs@virtuozzo.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge android-4.4.164 (564ce1b) into msm-4.4Srinivasarao P2018-11-21
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-564ce1b Linux 4.4.164 drm/i915/hdmi: Add HDMI 2.0 audio clock recovery N values drm/dp_mst: Check if primary mstb is null drm/rockchip: Allow driver to be shutdown on reboot/kexec mm: migration: fix migration of huge PMD shared pages hugetlbfs: fix kernel BUG at fs/hugetlbfs/inode.c:444! configfs: replace strncpy with memcpy fuse: fix leaked notify reply rtc: hctosys: Add missing range error reporting sunrpc: correct the computation for page_ptr when truncating mount: Prevent MNT_DETACH from disconnecting locked mounts mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts mount: Retest MNT_LOCKED in do_umount ext4: fix buffer leak in __ext4_read_dirblock() on error path ext4: fix buffer leak in ext4_xattr_move_to_block() on error path ext4: release bs.bh before re-using in ext4_xattr_block_find() ext4: fix possible leak of sbi->s_group_desc_leak in error path ext4: avoid possible double brelse() in add_new_gdb() on error path ext4: fix missing cleanup if ext4_alloc_flex_bg_array() fails while resizing ext4: avoid buffer leak in ext4_orphan_add() after prior errors ext4: fix possible inode leak in the retry loop of ext4_resize_fs() ext4: avoid potential extra brelse in setup_new_flex_group_blocks() ext4: add missing brelse() add_new_gdb_meta_bg()'s error path ext4: add missing brelse() in set_flexbg_block_bitmap()'s error path ext4: add missing brelse() update_backups()'s error path clockevents/drivers/i8253: Add support for PIT shutdown quirk Btrfs: fix data corruption due to cloning of eof block arch/alpha, termios: implement BOTHER, IBSHIFT and termios2 termios, tty/tty_baudrate.c: fix buffer overrun mtd: docg3: don't set conflicting BCH_CONST_PARAMS option mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings ocfs2: fix a misuse a of brelse after failing ocfs2_check_dir_entry vhost/scsi: truncate T10 PI iov_iter to prot_bytes mach64: fix image corruption due to reading accelerator registers mach64: fix display corruption on big endian machines libceph: bump CEPH_MSG_MAX_DATA_LEN clk: s2mps11: Fix matching when built as module and DT node contains compatible xtensa: fix boot parameters address translation xtensa: make sure bFLT stack is 16 byte aligned xtensa: add NOTES section to the linker script MIPS: Loongson-3: Fix BRIDGE irq delivery problem MIPS: Loongson-3: Fix CPU UART irq delivery problem bna: ethtool: Avoid reading past end of buffer e1000: fix race condition between e1000_down() and e1000_watchdog e1000: avoid null pointer dereference on invalid stat type mm: do not bug_on on incorrect length in __mm_populate() fs, elf: make sure to page align bss in load_elf_library mm: refuse wrapped vm_brk requests binfmt_elf: fix calculations for bss padding mm, elf: handle vm_brk error fuse: set FR_SENT while locked fuse: fix blocked_waitq wakeup fuse: Fix use-after-free in fuse_dev_do_write() fuse: Fix use-after-free in fuse_dev_do_read() scsi: qla2xxx: Fix incorrect port speed being set for FC adapters cdrom: fix improper type cast, which can leat to information leak. 9p: clear dangling pointers in p9stat_free 9p locks: fix glock.client_id leak in do_lock media: tvp5150: fix width alignment during set_selection() sc16is7xx: Fix for multi-channel stall powerpc/boot: Ensure _zimage_start is a weak symbol MIPS: kexec: Mark CPU offline before disabling local IRQ media: pci: cx23885: handle adding to list failure drm/omap: fix memory barrier bug in DMM driver powerpc/nohash: fix undefined behaviour when testing page size support tty: check name length in tty_find_polling_driver() MD: fix invalid stored role for a disk - try2 btrfs: set max_extent_size properly Btrfs: fix null pointer dereference on compressed write path error btrfs: qgroup: Dirty all qgroups before rescan Btrfs: fix wrong dentries after fsync of file that got its parent replaced btrfs: make sure we create all new block groups btrfs: reset max_extent_size on clear in a bitmap btrfs: wait on caching when putting the bg cache btrfs: don't attempt to trim devices that don't support it btrfs: iterate all devices during trim, instead of fs_devices::alloc_list btrfs: locking: Add extra check in btrfs_init_new_buffer() to avoid deadlock btrfs: Handle owner mismatch gracefully when walking up tree soc/tegra: pmc: Fix child-node lookup arm64: dts: stratix10: Correct System Manager register size Cramfs: fix abad comparison when wrap-arounds occur ext4: avoid running out of journal credits when appending to an inline file media: em28xx: make v4l2-compliance happier by starting sequence on zero media: em28xx: fix input name for Terratec AV 350 media: em28xx: use a default format if TRY_FMT fails xen: fix xen_qlock_wait() kgdboc: Passing ekgdboc to command line causes panic TC: Set DMA masks for devices MIPS: OCTEON: fix out of bounds array access on CN68XX powerpc/msi: Fix compile error on mpc83xx dm ioctl: harden copy_params()'s copy_from_user() from malicious users lockd: fix access beyond unterminated strings in prints nfsd: Fix an Oops in free_session() NFSv4.1: Fix the r/wsize checking genirq: Fix race on spurious interrupt detection printk: Fix panic caused by passing log_buf_len to command line smb3: on kerberos mount if server doesn't specify auth type use krb5 smb3: do not attempt cifs operation in smb3 query info error path smb3: allow stats which track session and share reconnects to be reset w1: omap-hdq: fix missing bus unregister at removal iio: adc: at91: fix wrong channel number in triggered buffer mode iio: adc: at91: fix acking DRDY irq on simple conversions kbuild: fix kernel/bounds.c 'W=1' warning hugetlbfs: dirty pages as they are added to pagecache ima: fix showing large 'violations' or 'runtime_measurements_count' crypto: lrw - Fix out-of bounds access on counter overflow signal/GenWQE: Fix sending of SIGKILL PCI: Add Device IDs for Intel GPU "spurious interrupt" quirk HID: hiddev: fix potential Spectre v1 ext4: initialize retries variable in ext4_da_write_inline_data_begin() gfs2_meta: ->mount() can get NULL dev_name jbd2: fix use after free in jbd2_log_do_checkpoint() libnvdimm: Hold reference on parent while scheduling async init net/ipv4: defensive cipso option parsing xen: make xen_qlock_wait() nestable xen: fix race in xen_qlock_wait() tpm: Restore functionality to xen vtpm driver. xen-swiotlb: use actually allocated size on check physical continuous ALSA: hda: Check the non-cached stream buffers more explicitly dmaengine: dma-jz4780: Return error if not probed from DT signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init scsi: lpfc: Correct soft lockup when running mds diagnostics uio: ensure class is registered before devices driver/dma/ioat: Call del_timer_sync() without holding prep_lock usb: chipidea: Prevent unbalanced IRQ disable MD: fix invalid stored role for a disk ext4: fix argument checking in EXT4_IOC_MOVE_EXT tpm: suppress transmit cmd error logs when TPM 1.2 is disabled/deactivated scsi: megaraid_sas: fix a missing-check bug scsi: esp_scsi: Track residual for PIO transfers ath10k: schedule hardware restart if WMI command times out pinctrl: ssbi-gpio: Fix pm8xxx_pin_config_get() to be compliant pinctrl: spmi-mpp: Fix pmic_mpp_config_get() to be compliant pinctrl: qcom: spmi-mpp: Fix drive strength setting ACPI / LPSS: Add alternative ACPI HIDs for Cherry Trail DMA controllers kprobes: Return error if we fail to reuse kprobe instead of BUG_ON() pinctrl: qcom: spmi-mpp: Fix err handling of pmic_mpp_set_mux x86: boot: Fix EFI stub alignment Bluetooth: btbcm: Add entry for BCM4335C0 UART bluetooth mmc: sdhci-pci-o2micro: Add quirk for O2 Micro dev 0x8620 rev 0x01 perf tools: Cleanup trace-event-info 'tdata' leak perf tools: Free temporary 'sys' string in read_event_files() tun: Consistently configure generic netdev params via rtnetlink swim: fix cleanup on setup error ataflop: fix error handling during setup locking/lockdep: Fix debug_locks off performance problem selftests: ftrace: Add synthetic event syntax testcase net: qla3xxx: Remove overflowing shift statement x86/fpu: Remove second definition of fpu in __fpu__restore_sig() sparc: Fix single-pcr perf event counter management. x86/kconfig: Fall back to ticket spinlocks x86/corruption-check: Fix panic in memory_corruption_check() when boot option without value is provided ALSA: ca0106: Disable IZD on SB0570 DAC to fix audio pops ALSA: hda - Add mic quirk for the Lenovo G50-30 (17aa:3905) parisc: Fix map_pages() to not overwrite existing pte entries parisc: Fix address in HPMC IVA ipmi: Fix timer race with module unload pcmcia: Implement CLKRUN protocol disabling for Ricoh bridges jffs2: free jffs2_sb_info through jffs2_kill_sb() hwmon: (pmbus) Fix page count auto-detection. bcache: fix miss key refill->end in writeback ANDROID: zram: set comp_len to PAGE_SIZE when page is huge Conflicts: drivers/hid/usbhid/hiddev.c Change-Id: I42874613e3b4102ef4ed051e1e8ed25b2d4ae7f2 Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
| * mm: migration: fix migration of huge PMD shared pagesMike Kravetz2018-11-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 017b1660df89f5fb4bfe66c34e35f7d2031100c7 upstream. The page migration code employs try_to_unmap() to try and unmap the source page. This is accomplished by using rmap_walk to find all vmas where the page is mapped. This search stops when page mapcount is zero. For shared PMD huge pages, the page map count is always 1 no matter the number of mappings. Shared mappings are tracked via the reference count of the PMD page. Therefore, try_to_unmap stops prematurely and does not completely unmap all mappings of the source page. This problem can result is data corruption as writes to the original source page can happen after contents of the page are copied to the target page. Hence, data is lost. This problem was originally seen as DB corruption of shared global areas after a huge page was soft offlined due to ECC memory errors. DB developers noticed they could reproduce the issue by (hotplug) offlining memory used to back huge pages. A simple testcase can reproduce the problem by creating a shared PMD mapping (note that this must be at least PUD_SIZE in size and PUD_SIZE aligned (1GB on x86)), and using migrate_pages() to migrate process pages between nodes while continually writing to the huge pages being migrated. To fix, have the try_to_unmap_one routine check for huge PMD sharing by calling huge_pmd_unshare for hugetlbfs huge pages. If it is a shared mapping it will be 'unshared' which removes the page table entry and drops the reference on the PMD page. After this, flush caches and TLB. mmu notifiers are called before locking page tables, but we can not be sure of PMD sharing until page tables are locked. Therefore, check for the possibility of PMD sharing before locking so that notifiers can prepare for the worst possible case. Link: http://lkml.kernel.org/r/20180823205917.16297-2-mike.kravetz@oracle.com [mike.kravetz@oracle.com: make _range_in_vma() a static inline] Link: http://lkml.kernel.org/r/6063f215-a5c8-2f0c-465a-2c515ddc952d@oracle.com Fixes: 39dde65c9940 ("shared page table for hugetlb page") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge android-4.4.108 (55b3b8c) into msm-4.4Srinivasarao P2018-01-18
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-55b3b8c Linux 4.4.108 alpha: fix build failures ALSA: hda - Fix yet another i915 pointer leftover in error path ALSA: hda - Degrade i915 binding failure message ALSA: hda - Clear the leftover component assignment at snd_hdac_i915_exit() Revert "Bluetooth: btusb: driver to enable the usb-wakeup feature" MIPS: math-emu: Fix final emulation phase for certain instructions thermal: hisilicon: Handle return value of clk_prepare_enable cpuidle: fix broadcast control when broadcast can not be entered rtc: set the alarm to the next expiring timer tcp: fix under-evaluated ssthresh in TCP Vegas fm10k: ensure we process SM mbx when processing VF mbx scsi: lpfc: PLOGI failures during NPIV testing scsi: lpfc: Fix secure firmware updates PCI/AER: Report non-fatal errors only to the affected endpoint ixgbe: fix use of uninitialized padding igb: check memory allocation failure PCI: Create SR-IOV virtfn/physfn links before attaching driver scsi: mpt3sas: Fix IO error occurs on pulling out a drive from RAID1 volume created on two SATA drive scsi: cxgb4i: fix Tx skb leak PCI: Avoid bus reset if bridge itself is broken net: phy: at803x: Change error to EINVAL for invalid MAC rtc: pl031: make interrupt optional crypto: crypto4xx - increase context and scatter ring buffer elements backlight: pwm_bl: Fix overflow condition bnxt_en: Fix NULL pointer dereference in reopen failure path cpuidle: powernv: Pass correct drv->cpumask for registration ARM: dma-mapping: disallow dma_get_sgtable() for non-kernel managed memory netfilter: nfnetlink_queue: fix secctx memory leak xhci: plat: Register shutdown for xhci_plat isdn: kcapi: avoid uninitialized data KVM: pci-assign: do not map smm memory slot pages in vt-d page tables ARM: dts: am335x-evmsk: adjust mmc2 param to allow suspend netfilter: nf_nat_snmp: Fix panic when snmp_trap_helper fails to register netfilter: nfnl_cthelper: fix a race when walk the nf_ct_helper_hash table irda: vlsi_ir: fix check for DMA mapping errors RDMA/iser: Fix possible mr leak on device removal event i40e: Do not enable NAPI on q_vectors that have no rings net: Do not allow negative values for busy_read and busy_poll sysctl interfaces bna: avoid writing uninitialized data into hw registers s390/qeth: no ETH header for outbound AF_IUCV r8152: prevent the driver from transmitting packets with carrier off HID: xinmo: fix for out of range for THT 2P arcade controller. hwmon: (asus_atk0110) fix uninitialized data access ARM: dts: ti: fix PCI bus dtc warnings KVM: VMX: Fix enable VPID conditions KVM: x86: correct async page present tracepoint scsi: lpfc: Fix PT2PT PRLI reject pinctrl: st: add irq_request/release_resources callbacks inet: frag: release spinlock before calling icmp_send() netfilter: nfnl_cthelper: Fix memory leak netfilter: nfnl_cthelper: fix runtime expectation policy updates usb: gadget: udc: remove pointer dereference after free usb: gadget: f_uvc: Sanity check wMaxPacketSize for SuperSpeed net: qmi_wwan: Add USB IDs for MDM6600 modem on Motorola Droid 4 bna: integer overflow bug in debugfs sch_dsmark: fix invalid skb_cow() usage crypto: deadlock between crypto_alg_sem/rtnl_mutex/genl_mutex r8152: fix the list rx_done may be used without initialization cpuidle: Validate cpu_dev in cpuidle_add_sysfs() arm: kprobes: Align stack to 8-bytes in test code arm: kprobes: Fix the return address of multiple kretprobes ALSA: hda - add support for docking station for HP 840 G3 ALSA: hda - add support for docking station for HP 820 G2 x86/irq: Do not substract irq_tlb_count from irq_call_count sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off() ARM: Hide finish_arch_post_lock_switch() from modules x86/mm, sched/core: Turn off IRQs in switch_mm() x86/mm, sched/core: Uninline switch_mm() x86/mm: Build arch/x86/mm/tlb.c even on !SMP sched/core: Add switch_mm_irqs_off() and use it in the scheduler mm/mmu_context, sched/core: Fix mmu_context.h assumption mm/rmap: batched invalidations should use existing api x86/mm: If INVPCID is available, use it to flush global mappings x86/mm: Add a 'noinvpcid' boot option to turn off INVPCID x86/mm: Fix INVPCID asm constraint x86/mm: Add INVPCID helpers cxl: Check if vphb exists before iterating over AFU devices arm64: Initialise high_memory global variable earlier ANDROID: binder: Remove obsolete proc waitqueue. Change-Id: Ie954ccd1dbd861672345bb0ee879273be4d0a441 Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
| * mm/rmap: batched invalidations should use existing apiNadav Amit2017-12-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 858eaaa711700ce4595e039441e239e56d7b9514 upstream. The recently introduced batched invalidations mechanism uses its own mechanism for shootdown. However, it does wrong accounting of interrupts (e.g., inc_irq_stat is called for local invalidations), trace-points (e.g., TLB_REMOTE_SHOOTDOWN for local invalidations) and may break some platforms as it bypasses the invalidation mechanisms of Xen and SGI UV. This patch reuses the existing TLB flushing mechnaisms instead. We use NULL as mm to indicate a global invalidation is required. Fixes 72b252aed506b8 ("mm: send one IPI per CPU to TLB flush all entries after unmapping pages") Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@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>
* | Merge android-4.4@4b8fc9f (v4.4.82) into msm-4.4Blagovest Kolenichev2017-09-01
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-4b8fc9f UPSTREAM: locking: avoid passing around 'thread_info' in mutex debugging code ANDROID: arm64: fix undeclared 'init_thread_info' error UPSTREAM: kdb: use task_cpu() instead of task_thread_info()->cpu Linux 4.4.82 net: account for current skb length when deciding about UFO ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output mm/mempool: avoid KASAN marking mempool poison checks as use-after-free KVM: arm/arm64: Handle hva aging while destroying the vm sparc64: Prevent perf from running during super critical sections udp: consistently apply ufo or fragmentation revert "ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output" revert "net: account for current skb length when deciding about UFO" packet: fix tp_reserve race in packet_set_ring net: avoid skb_warn_bad_offload false positives on UFO tcp: fastopen: tcp_connect() must refresh the route net: sched: set xt_tgchk_param par.nft_compat as 0 in ipt_init_target bpf, s390: fix jit branch offset related to ldimm64 net: fix keepalive code vs TCP_FASTOPEN_CONNECT tcp: avoid setting cwnd to invalid ssthresh after cwnd reduction states ANDROID: keychord: Fix for a memory leak in keychord. ANDROID: keychord: Fix races in keychord_write. Use %zu to print resid (size_t). ANDROID: keychord: Fix a slab out-of-bounds read. Linux 4.4.81 workqueue: implicit ordered attribute should be overridable net: account for current skb length when deciding about UFO ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output mm: don't dereference struct page fields of invalid pages signal: protect SIGNAL_UNKILLABLE from unintentional clearing. lib/Kconfig.debug: fix frv build failure mm, slab: make sure that KMALLOC_MAX_SIZE will fit into MAX_ORDER ARM: 8632/1: ftrace: fix syscall name matching virtio_blk: fix panic in initialization error path drm/virtio: fix framebuffer sparse warning scsi: qla2xxx: Get mutex lock before checking optrom_state phy state machine: failsafe leave invalid RUNNING state x86/boot: Add missing declaration of string functions tg3: Fix race condition in tg3_get_stats64(). net: phy: dp83867: fix irq generation sh_eth: R8A7740 supports packet shecksumming wext: handle NULL extra data in iwe_stream_add_point better sparc64: Measure receiver forward progress to avoid send mondo timeout xen-netback: correctly schedule rate-limited queues net: phy: Fix PHY unbind crash net: phy: Correctly process PHY_HALTED in phy_stop_machine() net/mlx5: Fix command bad flow on command entry allocation failure sctp: fix the check for _sctp_walk_params and _sctp_walk_errors sctp: don't dereference ptr before leaving _sctp_walk_{params, errors}() dccp: fix a memleak for dccp_feat_init err process dccp: fix a memleak that dccp_ipv4 doesn't put reqsk properly dccp: fix a memleak that dccp_ipv6 doesn't put reqsk properly net: ethernet: nb8800: Handle all 4 RGMII modes identically ipv6: Don't increase IPSTATS_MIB_FRAGFAILS twice in ip6_fragment() packet: fix use-after-free in prb_retire_rx_blk_timer_expired() openvswitch: fix potential out of bound access in parse_ct mcs7780: Fix initialization when CONFIG_VMAP_STACK is enabled rtnetlink: allocate more memory for dev_set_mac_address() ipv4: initialize fib_trie prior to register_netdev_notifier call. ipv6: avoid overflow of offset in ip6_find_1stfragopt net: Zero terminate ifr_name in dev_ifname(). ipv4: ipv6: initialize treq->txhash in cookie_v[46]_check() saa7164: fix double fetch PCIe access condition drm: rcar-du: fix backport bug f2fs: sanity check checkpoint segno and blkoff media: lirc: LIRC_GET_REC_RESOLUTION should return microseconds mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries iser-target: Avoid isert_conn->cm_id dereference in isert_login_recv_done iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP iscsi-target: Fix initial login PDU asynchronous socket close OOPs iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race iscsi-target: Always wait for kthread_should_stop() before kthread exit target: Avoid mappedlun symlink creation during lun shutdown media: platform: davinci: return -EINVAL for VPFE_CMD_S_CCDC_RAW_PARAMS ioctl ARM: dts: armada-38x: Fix irq type for pca955 ext4: fix overflow caused by missing cast in ext4_resize_fs() ext4: fix SEEK_HOLE/SEEK_DATA for blocksize < pagesize mm/page_alloc: Remove kernel address exposure in free_reserved_area() KVM: async_pf: make rcu irq exit if not triggered from idle task ASoC: do not close shared backend dailink ALSA: hda - Fix speaker output from VAIO VPCL14M1R workqueue: restore WQ_UNBOUND/max_active==1 to be ordered libata: array underflow in ata_find_dev() ANDROID: binder: don't queue async transactions to thread. ANDROID: binder: don't enqueue death notifications to thread todo. ANDROID: binder: call poll_wait() unconditionally. android: configs: move quota-related configs to recommended BACKPORT: arm64: split thread_info from task stack UPSTREAM: arm64: assembler: introduce ldr_this_cpu UPSTREAM: arm64: make cpu number a percpu variable UPSTREAM: arm64: smp: prepare for smp_processor_id() rework BACKPORT: arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx UPSTREAM: arm64: prep stack walkers for THREAD_INFO_IN_TASK UPSTREAM: arm64: unexport walk_stackframe UPSTREAM: arm64: traps: simplify die() and __die() UPSTREAM: arm64: factor out current_stack_pointer BACKPORT: arm64: asm-offsets: remove unused definitions UPSTREAM: arm64: thread_info remove stale items UPSTREAM: thread_info: include <current.h> for THREAD_INFO_IN_TASK UPSTREAM: thread_info: factor out restart_block UPSTREAM: kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function UPSTREAM: sched/core: Add try_get_task_stack() and put_task_stack() UPSTREAM: sched/core: Allow putting thread_info into task_struct UPSTREAM: printk: when dumping regs, show the stack, not thread_info UPSTREAM: fix up initial thread stack pointer vs thread_info confusion UPSTREAM: Clarify naming of thread info/stack allocators ANDROID: sdcardfs: override credential for ioctl to lower fs Conflicts: android/configs/android-base.cfg arch/arm64/Kconfig arch/arm64/include/asm/suspend.h arch/arm64/kernel/head.S arch/arm64/kernel/smp.c arch/arm64/kernel/suspend.c arch/arm64/kernel/traps.c arch/arm64/mm/proc.S kernel/fork.c sound/soc/soc-pcm.c Change-Id: I273e216c94899a838bbd208391c6cbe20b2bf683 Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>
| * mm, mprotect: flush TLB if potentially racing with a parallel reclaim ↵Mel Gorman2017-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | leaving stale TLB entries commit 3ea277194daaeaa84ce75180ec7c7a2075027a68 upstream. Stable note for 4.4: The upstream patch patches madvise(MADV_FREE) but 4.4 does not have support for that feature. The changelog is left as-is but the hunk related to madvise is omitted from the backport. Nadav Amit identified a theoritical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. For some operations like mprotect, it's not necessarily a data integrity issue but it is a correctness issue as there is a window where an mprotect that limits access still allows access. For munmap, it's potentially a data integrity issue although the race is massive as an munmap, mmap and return to userspace must all complete between the window when reclaim drops the PTL and flushes the TLB. However, it's theoritically possible so handle this issue by flushing the mm if reclaim is potentially currently batching TLB flushes. Other instances where a flush is required for a present pte should be ok as either the page lock is held preventing parallel reclaim or a page reference count is elevated preventing a parallel free leading to corruption. In the case of page_mkclean there isn't an obvious path that userspace could take advantage of without using the operations that are guarded by this patch. Other users such as gup as a race with reclaim looks just at PTEs. huge page variants should be ok as they don't race with reclaim. mincore only looks at PTEs. userfault also should be ok as if a parallel reclaim takes place, it will either fault the page back in or read some of the data before the flush occurs triggering a fault. Note that a variant of this patch was acked by Andy Lutomirski but this was for the x86 parts on top of his PCID work which didn't make the 4.13 merge window as expected. His ack is dropped from this version and there will be a follow-on patch on top of PCID that will include his ack. [akpm@linux-foundation.org: tweak comments] [akpm@linux-foundation.org: fix spello] Link: http://lkml.kernel.org/r/20170717155523.emckq2esjro6hf3z@suse.de Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@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>
* | mm: Enhance per process reclaim to consider shared pagesMinchan Kim2016-06-22
|/ | | | | | | | | | | | | | | | | | | | | Some pages could be shared by several processes. (ex, libc) In case of that, it's too bad to reclaim them from the beginnig. This patch causes VM to keep them on memory until last task try to reclaim them so shared pages will be reclaimed only if all of task has gone swapping out. This feature doesn't handle non-linear mapping on ramfs because it's very time-consuming and doesn't make sure of reclaiming and not common. Change-Id: I7e5f34f2e947f5db6d405867fe2ad34863ca40f7 Signed-off-by: Sangseok Lee <sangseok.lee@lge.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Patch-mainline: linux-mm @ 9 May 2013 16:21:27 [vinmenon@codeaurora.org: trivial merge conflict fixes + changes to make the patch work with 3.18 kernel] Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* mm: page migration use migration entry for swapcache tooHugh Dickins2015-11-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hitherto page migration has avoided using a migration entry for a swapcache page mapped into userspace, apparently for historical reasons. So any page blessed with swapcache would entail a minor fault when it's next touched, which page migration otherwise tries to avoid. Swapcache in an mlocked area is rare, so won't often matter, but still better fixed. Just rearrange the block in try_to_unmap_one(), to handle TTU_MIGRATION before checking PageAnon, that's all (apart from some reindenting). Well, no, that's not quite all: doesn't this by the way fix a soft_dirty bug, that page migration of a file page was forgetting to transfer the soft_dirty bit? Probably not a serious bug: if I understand correctly, soft_dirty afficionados usually have to handle file pages separately anyway; but we publish the bit in /proc/<pid>/pagemap on file mappings as well as anonymous, so page migration ought not to perturb it. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rmap use pte lock not mmap_sem to set PageMlockedHugh Dickins2015-11-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KernelThreadSanitizer (ktsan) has shown that the down_read_trylock() of mmap_sem in try_to_unmap_one() (when going to set PageMlocked on a page found mapped in a VM_LOCKED vma) is ineffective against races with exit_mmap()'s munlock_vma_pages_all(), because mmap_sem is not held when tearing down an mm. But that's okay, those races are benign; and although we've believed for years in that ugly down_read_trylock(), it's unsuitable for the job, and frustrates the good intention of setting PageMlocked when it fails. It just doesn't matter if here we read vm_flags an instant before or after a racing mlock() or munlock() or exit_mmap() sets or clears VM_LOCKED: the syscalls (or exit) work their way up the address space (taking pt locks after updating vm_flags) to establish the final state. We do still need to be careful never to mark a page Mlocked (hence unevictable) by any race that will not be corrected shortly after. The page lock protects from many of the races, but not all (a page is not necessarily locked when it's unmapped). But the pte lock we just dropped is good to cover the rest (and serializes even with munlock_vma_pages_all(), so no special barriers required): now hold on to the pte lock while calling mlock_vma_page(). Is that lock ordering safe? Yes, that's how follow_page_pte() calls it, and how page_remove_rmap() calls the complementary clear_page_mlock(). This fixes the following case (though not a case which anyone has complained of), which mmap_sem did not: truncation's preliminary unmap_mapping_range() is supposed to remove even the anonymous COWs of filecache pages, and that might race with try_to_unmap_one() on a VM_LOCKED vma, so that mlock_vma_page() sets PageMlocked just after zap_pte_range() unmaps the page, causing "Bad page state (mlocked)" when freed. The pte lock protects against this. You could say that it also protects against the more ordinary case, racing with the preliminary unmapping of a filecache page itself: but in our current tree, that's independently protected by i_mmap_rwsem; and that race would be why "Bad page state (mlocked)" was seen before commit 48ec833b7851 ("Revert mm/memory.c: share the i_mmap_rwsem"). Vlastimil Babka points out another race which this patch protects against. try_to_unmap_one() might reach its mlock_vma_page() TestSetPageMlocked a moment after munlock_vma_pages_all() did its Phase 1 TestClearPageMlocked: leaving PageMlocked and unevictable when it should be evictable. mmap_sem is ineffective because exit_mmap() does not hold it; page lock ineffective because __munlock_pagevec() only takes it afterwards, in Phase 2; pte lock is effective because __munlock_pagevec_fill() takes it to get the page, after VM_LOCKED was cleared from vm_flags, so visible to try_to_unmap_one. Kirill Shutemov points out that if the compiler chooses to implement a "vma->vm_flags &= VM_WHATEVER" or "vma->vm_flags |= VM_WHATEVER" operation with an intermediate store of unrelated bits set, since I'm here foregoing its usual protection by mmap_sem, try_to_unmap_one() might catch sight of a spurious VM_LOCKED in vm_flags, and make the wrong decision. This does not appear to be an immediate problem, but we may want to define vm_flags accessors in future, to guard against such a possibility. While we're here, make a related optimization in try_to_munmap_one(): if it's doing TTU_MUNLOCK, then there's no point at all in descending the page tables and getting the pt lock, unless the vma is VM_LOCKED. Yes, that can change racily, but it can change racily even without the optimization: it's not critical. Far better not to waste time here. Stopped short of separating try_to_munlock_one() from try_to_munmap_one() on this occasion, but that's probably the sensible next step - with a rename, given that try_to_munlock()'s business is to try to set Mlocked. Updated the unevictable-lru Documentation, to remove its reference to mmap semaphore, but found a few more updates needed in just that area. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ksm: add cond_resched() to the rmap_walksAndrea Arcangeli2015-11-05
| | | | | | | | | | | While at it add it to the file and anon walks too. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Petr Holasek <pholasek@redhat.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: hugetlb: proc: add HugetlbPages field to /proc/PID/statusNaoya Horiguchi2015-11-05
| | | | | | | | | | | | | | | | Currently there's no easy way to get per-process usage of hugetlb pages, which is inconvenient because userspace applications which use hugetlb typically want to control their processes on the basis of how much memory (including hugetlb) they use. So this patch simply provides easy access to the info via /proc/PID/status. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Joern Engel <joern@logfs.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce idle page trackingVladimir Davydov2015-09-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Knowing the portion of memory that is not used by a certain application or memory cgroup (idle memory) can be useful for partitioning the system efficiently, e.g. by setting memory cgroup limits appropriately. Currently, the only means to estimate the amount of idle memory provided by the kernel is /proc/PID/{clear_refs,smaps}: the user can clear the access bit for all pages mapped to a particular process by writing 1 to clear_refs, wait for some time, and then count smaps:Referenced. However, this method has two serious shortcomings: - it does not count unmapped file pages - it affects the reclaimer logic To overcome these drawbacks, this patch introduces two new page flags, Idle and Young, and a new sysfs file, /sys/kernel/mm/page_idle/bitmap. A page's Idle flag can only be set from userspace by setting bit in /sys/kernel/mm/page_idle/bitmap at the offset corresponding to the page, and it is cleared whenever the page is accessed either through page tables (it is cleared in page_referenced() in this case) or using the read(2) system call (mark_page_accessed()). Thus by setting the Idle flag for pages of a particular workload, which can be found e.g. by reading /proc/PID/pagemap, waiting for some time to let the workload access its working set, and then reading the bitmap file, one can estimate the amount of pages that are not used by the workload. The Young page flag is used to avoid interference with the memory reclaimer. A page's Young flag is set whenever the Access bit of a page table entry pointing to the page is cleared by writing to the bitmap file. If page_referenced() is called on a Young page, it will add 1 to its return value, therefore concealing the fact that the Access bit was cleared. Note, since there is no room for extra page flags on 32 bit, this feature uses extended page flags when compiled on 32 bit. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: kpageidle requires an MMU] [akpm@linux-foundation.org: decouple from page-flags rework] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: defer flush of writable TLB entriesMel Gorman2015-09-04
| | | | | | | | | | | | | | | | If a PTE is unmapped and it's dirty then it was writable recently. Due to deferred TLB flushing, it's best to assume a writable TLB cache entry exists. With that assumption, the TLB must be flushed before any IO can start or the page is freed to avoid lost writes or data corruption. This patch defers flushing of potentially writable TLBs as long as possible. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: send one IPI per CPU to TLB flush all entries after unmapping pagesMel Gorman2015-09-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An IPI is sent to flush remote TLBs when a page is unmapped that was potentially accesssed by other CPUs. There are many circumstances where this happens but the obvious one is kswapd reclaiming pages belonging to a running process as kswapd and the task are likely running on separate CPUs. On small machines, this is not a significant problem but as machine gets larger with more cores and more memory, the cost of these IPIs can be high. This patch uses a simple structure that tracks CPUs that potentially have TLB entries for pages being unmapped. When the unmapping is complete, the full TLB is flushed on the assumption that a refill cost is lower than flushing individual entries. Architectures wishing to do this must give the following guarantee. If a clean page is unmapped and not immediately flushed, the architecture must guarantee that a write to that linear address from a CPU with a cached TLB entry will trap a page fault. This is essentially what the kernel already depends on but the window is much larger with this patch applied and is worth highlighting. The architecture should consider whether the cost of the full TLB flush is higher than sending an IPI to flush each individual entry. An additional architecture helper called flush_tlb_local is required. It's a trivial wrapper with some accounting in the x86 case. The impact of this patch depends on the workload as measuring any benefit requires both mapped pages co-located on the LRU and memory pressure. The case with the biggest impact is multiple processes reading mapped pages taken from the vm-scalability test suite. The test case uses NR_CPU readers of mapped files that consume 10*RAM. Linear mapped reader on a 4-node machine with 64G RAM and 48 CPUs 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 Ops lru-file-mmap-read-elapsed 159.62 ( 0.00%) 120.68 ( 24.40%) Ops lru-file-mmap-read-time_range 30.59 ( 0.00%) 2.80 ( 90.85%) Ops lru-file-mmap-read-time_stddv 6.70 ( 0.00%) 0.64 ( 90.38%) 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 User 581.00 611.43 System 5804.93 4111.76 Elapsed 161.03 122.12 This is showing that the readers completed 24.40% faster with 29% less system CPU time. From vmstats, it is known that the vanilla kernel was interrupted roughly 900K times per second during the steady phase of the test and the patched kernel was interrupts 180K times per second. The impact is lower on a single socket machine. 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 Ops lru-file-mmap-read-elapsed 25.33 ( 0.00%) 20.38 ( 19.54%) Ops lru-file-mmap-read-time_range 0.91 ( 0.00%) 1.44 (-58.24%) Ops lru-file-mmap-read-time_stddv 0.28 ( 0.00%) 0.47 (-65.34%) 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 User 58.09 57.64 System 111.82 76.56 Elapsed 27.29 22.55 It's still a noticeable improvement with vmstat showing interrupts went from roughly 500K per second to 45K per second. The patch will have no impact on workloads with no memory pressure or have relatively few mapped pages. It will have an unpredictable impact on the workload running on the CPU being flushed as it'll depend on how many TLB entries need to be refilled and how long that takes. Worst case, the TLB will be completely cleared of active entries when the target PFNs were not resident at all. [sasha.levin@oracle.com: trace tlb flush after disabling preemption in try_to_unmap_flush] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-blockLinus Torvalds2015-06-25
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull cgroup writeback support from Jens Axboe: "This is the big pull request for adding cgroup writeback support. This code has been in development for a long time, and it has been simmering in for-next for a good chunk of this cycle too. This is one of those problems that has been talked about for at least half a decade, finally there's a solution and code to go with it. Also see last weeks writeup on LWN: http://lwn.net/Articles/648292/" * 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits) writeback, blkio: add documentation for cgroup writeback support vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB writeback: do foreign inode detection iff cgroup writeback is enabled v9fs: fix error handling in v9fs_session_init() bdi: fix wrong error return value in cgwb_create() buffer: remove unusued 'ret' variable writeback: disassociate inodes from dying bdi_writebacks writeback: implement foreign cgroup inode bdi_writeback switching writeback: add lockdep annotation to inode_to_wb() writeback: use unlocked_inode_to_wb transaction in inode_congested() writeback: implement unlocked_inode_to_wb transaction and use it for stat updates writeback: implement [locked_]inode_to_wb_and_lock_list() writeback: implement foreign cgroup inode detection writeback: make writeback_control track the inode being written back writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb() mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use writeback: implement memcg writeback domain based throttling writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes writeback: implement memcg wb_domain writeback: update wb_over_bg_thresh() to use wb_domain aware operations ...
| * memcg: add per cgroup dirty page accountingGreg Thelen2015-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When modifying PG_Dirty on cached file pages, update the new MEM_CGROUP_STAT_DIRTY counter. This is done in the same places where global NR_FILE_DIRTY is managed. The new memcg stat is visible in the per memcg memory.stat cgroupfs file. The most recent past attempt at this was http://thread.gmane.org/gmane.linux.kernel.cgroups/8632 The new accounting supports future efforts to add per cgroup dirty page throttling and writeback. It also helps an administrator break down a container's memory usage and provides evidence to understand memcg oom kills (the new dirty count is included in memcg oom kill messages). The ability to move page accounting between memcg (memory.move_charge_at_immigrate) makes this accounting more complicated than the global counter. The existing mem_cgroup_{begin,end}_page_stat() lock is used to serialize move accounting with stat updates. Typical update operation: memcg = mem_cgroup_begin_page_stat(page) if (TestSetPageDirty()) { [...] mem_cgroup_update_page_stat(memcg) } mem_cgroup_end_page_stat(memcg) Summary of mem_cgroup_end_page_stat() overhead: - Without CONFIG_MEMCG it's a no-op - With CONFIG_MEMCG and no inter memcg task movement, it's just rcu_read_lock() - With CONFIG_MEMCG and inter memcg task movement, it's rcu_read_lock() + spin_lock_irqsave() A memcg parameter is added to several routines because their callers now grab mem_cgroup_begin_page_stat() which returns the memcg later needed by for mem_cgroup_update_page_stat(). Because mem_cgroup_begin_page_stat() may disable interrupts, some adjustments are needed: - move __mark_inode_dirty() from __set_page_dirty() to its caller. __mark_inode_dirty() locking does not want interrupts disabled. - use spin_lock_irqsave(tree_lock) rather than spin_lock_irq() in __delete_from_page_cache(), replace_page_cache_page(), invalidate_complete_page2(), and __remove_mapping(). text data bss dec hex filename 8925147 1774832 1785856 12485835 be84cb vmlinux-!CONFIG_MEMCG-before 8925339 1774832 1785856 12486027 be858b vmlinux-!CONFIG_MEMCG-after +192 text bytes 8965977 1784992 1785856 12536825 bf4bf9 vmlinux-CONFIG_MEMCG-before 8966750 1784992 1785856 12537598 bf4efe vmlinux-CONFIG_MEMCG-after +773 text bytes Performance tests run on v4.0-rc1-36-g4f671fe2f952. Lower is better for all metrics, they're all wall clock or cycle counts. The read and write fault benchmarks just measure fault time, they do not include I/O time. * CONFIG_MEMCG not set: baseline patched kbuild 1m25.030000(+-0.088% 3 samples) 1m25.426667(+-0.120% 3 samples) dd write 100 MiB 0.859211561 +-15.10% 0.874162885 +-15.03% dd write 200 MiB 1.670653105 +-17.87% 1.669384764 +-11.99% dd write 1000 MiB 8.434691190 +-14.15% 8.474733215 +-14.77% read fault cycles 254.0(+-0.000% 10 samples) 253.0(+-0.000% 10 samples) write fault cycles 2021.2(+-3.070% 10 samples) 1984.5(+-1.036% 10 samples) * CONFIG_MEMCG=y root_memcg: baseline patched kbuild 1m25.716667(+-0.105% 3 samples) 1m25.686667(+-0.153% 3 samples) dd write 100 MiB 0.855650830 +-14.90% 0.887557919 +-14.90% dd write 200 MiB 1.688322953 +-12.72% 1.667682724 +-13.33% dd write 1000 MiB 8.418601605 +-14.30% 8.673532299 +-15.00% read fault cycles 266.0(+-0.000% 10 samples) 266.0(+-0.000% 10 samples) write fault cycles 2051.7(+-1.349% 10 samples) 2049.6(+-1.686% 10 samples) * CONFIG_MEMCG=y non-root_memcg: baseline patched kbuild 1m26.120000(+-0.273% 3 samples) 1m25.763333(+-0.127% 3 samples) dd write 100 MiB 0.861723964 +-15.25% 0.818129350 +-14.82% dd write 200 MiB 1.669887569 +-13.30% 1.698645885 +-13.27% dd write 1000 MiB 8.383191730 +-14.65% 8.351742280 +-14.52% read fault cycles 265.7(+-0.172% 10 samples) 267.0(+-0.000% 10 samples) write fault cycles 2070.6(+-1.512% 10 samples) 2084.4(+-2.148% 10 samples) As expected anon page faults are not affected by this patch. tj: Updated to apply on top of the recent cancel_dirty_page() changes. Signed-off-by: Sha Zhengju <handai.szj@gmail.com> Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* | mm: clarify that the function operates on hugepage pteAneesh Kumar K.V2015-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have confusing functions to clear pmd, pmd_clear_* and pmd_clear. Add _huge_ to pmdp_clear functions so that we are clear that they operate on hugepage pte. We don't bother about other functions like pmdp_set_wrprotect, pmdp_clear_flush_young, because they operate on PTE bits and hence indicate they are operating on hugepage ptes Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | rmap: fix theoretical race between do_wp_page and shrink_active_listVladimir Davydov2015-06-24
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As noted by Paul the compiler is free to store a temporary result in a variable on stack, heap or global unless it is explicitly marked as volatile, see: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4455.html#sample-optimizations This can result in a race between do_wp_page() and shrink_active_list() as follows. In do_wp_page() we can call page_move_anon_rmap(), which sets page->mapping as follows: anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; page->mapping = (struct address_space *) anon_vma; The page in question may be on an LRU list, because nowhere in do_wp_page() we remove it from the list, neither do we take any LRU related locks. Although the page is locked, shrink_active_list() can still call page_referenced() on it concurrently, because the latter does not require an anonymous page to be locked: CPU0 CPU1 ---- ---- do_wp_page shrink_active_list lock_page page_referenced PageAnon->yes, so skip trylock_page page_move_anon_rmap page->mapping = anon_vma rmap_walk PageAnon->no rmap_walk_file BUG page->mapping += PAGE_MAPPING_ANON This patch fixes this race by explicitly forbidding the compiler to split page->mapping store in page_move_anon_rmap() with the aid of WRITE_ONCE. [akpm@linux-foundation.org: tweak comment, per Minchan] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove rest of ACCESS_ONCE() usagesJason Low2015-04-15
| | | | | | | | | | | | | | | | | We converted some of the usages of ACCESS_ONCE to READ_ONCE in the mm/ tree since it doesn't work reliably on non-scalar types. This patch removes the rest of the usages of ACCESS_ONCE, and use the new READ_ONCE API for the read accesses. This makes things cleaner, instead of using separate/multiple sets of APIs. Signed-off-by: Jason Low <jason.low2@hp.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix anon_vma->degree underflow in anon_vma endless growing preventionLeon Yu2015-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I have constantly stumbled upon "kernel BUG at mm/rmap.c:399!" after upgrading to 3.19 and had no luck with 4.0-rc1 neither. So, after looking into new logic introduced by commit 7a3ef208e662 ("mm: prevent endless growth of anon_vma hierarchy"), I found chances are that unlink_anon_vmas() is called without incrementing dst->anon_vma->degree in anon_vma_clone() due to allocation failure. If dst->anon_vma is not NULL in error path, its degree will be incorrectly decremented in unlink_anon_vmas() and eventually underflow when exiting as a result of another call to unlink_anon_vmas(). That's how "kernel BUG at mm/rmap.c:399!" is triggered for me. This patch fixes the underflow by dropping dst->anon_vma when allocation fails. It's safe to do so regardless of original value of dst->anon_vma because dst->anon_vma doesn't have valid meaning if anon_vma_clone() fails. Besides, callers don't care dst->anon_vma in such case neither. Also suggested by Michal Hocko, we can clean up vma_adjust() a bit as anon_vma_clone() now does the work. [akpm@linux-foundation.org: tweak comment] Fixes: 7a3ef208e662 ("mm: prevent endless growth of anon_vma hierarchy") Signed-off-by: Leon Yu <chianglungyu@gmail.com> Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: track move_lock state internallyJohannes Weiner2015-02-11
| | | | | | | | | | | | | The complexity of memcg page stat synchronization is currently leaking into the callsites, forcing them to keep track of the move_lock state and the IRQ flags. Simplify the API by tracking it in the memcg. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rmap: drop support of non-linear mappingsKirill A. Shutemov2015-02-10
| | | | | | | | | We don't create non-linear mappings anymore. Let's drop code which handles them in rmap. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: prevent endless growth of anon_vma hierarchyKonstantin Khlebnikov2015-01-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Constantly forking task causes unlimited grow of anon_vma chain. Each next child allocates new level of anon_vmas and links vma to all previous levels because pages might be inherited from any level. This patch adds heuristic which decides to reuse existing anon_vma instead of forking new one. It adds counter anon_vma->degree which counts linked vmas and directly descending anon_vmas and reuses anon_vma if counter is lower than two. As a result each anon_vma has either vma or at least two descending anon_vmas. In such trees half of nodes are leafs with alive vmas, thus count of anon_vmas is no more than two times bigger than count of vmas. This heuristic reuses anon_vmas as few as possible because each reuse adds false aliasing among vmas and rmap walker ought to scan more ptes when it searches where page is might be mapped. Link: http://lkml.kernel.org/r/20120816024610.GA5350@evergreen.ssec.wisc.edu Fixes: 5beb49305251 ("mm: change anon_vma linking to fix multi-process server scalability issue") [akpm@linux-foundation.org: fix typo, per Rik] Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reported-by: Daniel Forrest <dan.forrest@ssec.wisc.edu> Tested-by: Michal Hocko <mhocko@suse.cz> Tested-by: Jerome Marchand <jmarchan@redhat.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [2.6.34+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'for-linus' of ↵Linus Torvalds2014-12-20
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux Pull ACCESS_ONCE cleanup preparation from Christian Borntraeger: "kernel: Provide READ_ONCE and ASSIGN_ONCE As discussed on LKML http://marc.info/?i=54611D86.4040306%40de.ibm.com ACCESS_ONCE might fail with specific compilers for non-scalar accesses. Here is a set of patches to tackle that problem. The first patch introduce READ_ONCE and ASSIGN_ONCE. If the data structure is larger than the machine word size memcpy is used and a warning is emitted. The next patches fix up several in-tree users of ACCESS_ONCE on non-scalar types. This does not yet contain a patch that forces ACCESS_ONCE to work only on scalar types. This is targetted for the next merge window as Linux next already contains new offenders regarding ACCESS_ONCE vs. non-scalar types" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux: s390/kvm: REPLACE barrier fixup with READ_ONCE arm/spinlock: Replace ACCESS_ONCE with READ_ONCE arm64/spinlock: Replace ACCESS_ONCE READ_ONCE mips/gup: Replace ACCESS_ONCE with READ_ONCE x86/gup: Replace ACCESS_ONCE with READ_ONCE x86/spinlock: Replace ACCESS_ONCE with READ_ONCE mm: replace ACCESS_ONCE with READ_ONCE or barriers kernel: Provide READ_ONCE and ASSIGN_ONCE
| * mm: replace ACCESS_ONCE with READ_ONCE or barriersChristian Borntraeger2014-12-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ACCESS_ONCE does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) Let's change the code to access the page table elements with READ_ONCE that does implicit scalar accesses for the gup code. mm_find_pmd is tricky, because m68k and sparc(32bit) define pmd_t as array of longs. This code requires just that the pmd_present and pmd_trans_huge check are done on the same value, so a barrier is sufficent. A similar case is in handle_pte_fault. On ppc44x the word size is 32 bit, but a pte is 64 bit. A barrier is ok as well. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: linux-mm@kvack.org Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds2014-12-15
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull drm updates from Dave Airlie: "Highlights: - AMD KFD driver merge This is the AMD HSA interface for exposing a lowlevel interface for GPGPU use. They have an open source userspace built on top of this interface, and the code looks as good as it was going to get out of tree. - Initial atomic modesetting work The need for an atomic modesetting interface to allow userspace to try and send a complete set of modesetting state to the driver has arisen, and been suffering from neglect this past year. No more, the start of the common code and changes for msm driver to use it are in this tree. Ongoing work to get the userspace ioctl finished and the code clean will probably wait until next kernel. - DisplayID 1.3 and tiled monitor exposed to userspace. Tiled monitor property is now exposed for userspace to make use of. - Rockchip drm driver merged. - imx gpu driver moved out of staging Other stuff: - core: panel - MIPI DSI + new panels. expose suggested x/y properties for virtual GPUs - i915: Initial Skylake (SKL) support gen3/4 reset work start of dri1/ums removal infoframe tracking fixes for lots of things. - nouveau: tegra k1 voltage support GM204 modesetting support GT21x memory reclocking work - radeon: CI dpm fixes GPUVM improvements Initial DPM fan control - rcar-du: HDMI support added removed some support for old boards slave encoder driver for Analog Devices adv7511 - exynos: Exynos4415 SoC support - msm: a4xx gpu support atomic helper conversion - tegra: iommu support universal plane support ganged-mode DSI support - sti: HDMI i2c improvements - vmwgfx: some late fixes. - qxl: use suggested x/y properties" * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (969 commits) drm: sti: fix module compilation issue drm/i915: save/restore GMBUS freq across suspend/resume on gen4 drm: sti: correctly cleanup CRTC and planes drm: sti: add HQVDP plane drm: sti: add cursor plane drm: sti: enable auxiliary CRTC drm: sti: fix delay in VTG programming drm: sti: prepare sti_tvout to support auxiliary crtc drm: sti: use drm_crtc_vblank_{on/off} instead of drm_vblank_{on/off} drm: sti: fix hdmi avi infoframe drm: sti: remove event lock while disabling vblank drm: sti: simplify gdp code drm: sti: clear all mixer control drm: sti: remove gpio for HDMI hot plug detection drm: sti: allow to change hdmi ddc i2c adapter drm/doc: Document drm_add_modes_noedid() usage drm/i915: Remove '& 0xffff' from the mask given to WA_REG() drm/i915: Invert the mask and val arguments in wa_add() and WA_REG() drm: Zero out DRM object memory upon cleanup drm/i915/bdw: Fix the write setting up the WIZ hashing mode ...
| * \ Merge tag 'v3.18' into drm-nextDave Airlie2014-12-08
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 3.18 Backmerge Linus tree into -next as we had conflicts in i915/radeon/nouveau, and everyone was solving them individually. * tag 'v3.18': (57 commits) Linux 3.18 watchdog: s3c2410_wdt: Fix the mask bit offset for Exynos7 uapi: fix to export linux/vm_sockets.h i2c: cadence: Set the hardware time-out register to maximum value i2c: davinci: generate STP always when NACK is received ahci: disable MSI on SAMSUNG 0xa800 SSD context_tracking: Restore previous state in schedule_user slab: fix nodeid bounds check for non-contiguous node IDs lib/genalloc.c: export devm_gen_pool_create() for modules mm: fix anon_vma_clone() error treatment mm: fix swapoff hang after page migration and fork fat: fix oops on corrupted vfat fs ipc/sem.c: fully initialize sem_array before making it visible drivers/input/evdev.c: don't kfree() a vmalloc address cxgb4: Fill in supported link mode for SFP modules xen-netfront: Remove BUGs on paged skb data which crosses a page boundary mm/vmpressure.c: fix race in vmpressure_work_fn() mm: frontswap: invalidate expired data on a dup-store failure mm: do not overwrite reserved pages counter at show_mem() drm/radeon: kernel panic in drm_calc_vbltimestamp_from_scanoutpos with 3.18.0-rc6 ... Conflicts: drivers/gpu/drm/i915/intel_display.c drivers/gpu/drm/nouveau/nouveau_drm.c drivers/gpu/drm/radeon/radeon_cs.c
| * | | mmu_notifier: call mmu_notifier_invalidate_range() from VMMJoerg Roedel2014-11-13
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add calls to the new mmu_notifier_invalidate_range() function to all places in the VMM that need it. Signed-off-by: Joerg Roedel <jroedel@suse.de> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Jay Cornwall <Jay.Cornwall@amd.com> Cc: Oded Gabbay <Oded.Gabbay@amd.com> Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
* | | mm/rmap: calculate page offset when neededDavidlohr Bueso2014-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call page_to_pgoff() to get the page offset once we are sure we actually need it, and any very obvious initial function checks have passed. Trivial micro-optimization, and potentially save some cycles. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm/rmap: share the i_mmap_rwsemDavidlohr Bueso2014-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similarly to the anon memory counterpart, we can share the mapping's lock ownership as the interval tree is not modified when doing doing the walk, only the file page. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: convert i_mmap_mutex to rwsemDavidlohr Bueso2014-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The i_mmap_mutex is a close cousin of the anon vma lock, both protecting similar data, one for file backed pages and the other for anon memory. To this end, this lock can also be a rwsem. In addition, there are some important opportunities to share the lock when there are no tree modifications. This conversion is straightforward. For now, all users take the write lock. [sfr@canb.auug.org.au: update fremap.c] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: use new helper functions around the i_mmap_mutexDavidlohr Bueso2014-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert all open coded mutex_lock/unlock calls to the i_mmap_[lock/unlock]_write() helpers. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm, memcg: fix potential undefined behaviour in page stat accountingMichal Hocko2014-12-10
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit d7365e783edb ("mm: memcontrol: fix missed end-writeback page accounting") mem_cgroup_end_page_stat consumes locked and flags variables directly rather than via pointers which might trigger C undefined behavior as those variables are initialized only in the slow path of mem_cgroup_begin_page_stat. Although mem_cgroup_end_page_stat handles parameters correctly and touches them only when they hold a sensible value it is caller which loads a potentially uninitialized value which then might allow compiler to do crazy things. I haven't seen any warning from gcc and it seems that the current version (4.9) doesn't exploit this type undefined behavior but Sasha has reported the following: UBSan: Undefined behaviour in mm/rmap.c:1084:2 load of value 255 is not a valid value for type '_Bool' CPU: 4 PID: 8304 Comm: rngd Not tainted 3.18.0-rc2-next-20141029-sasha-00039-g77ed13d-dirty #1427 Call Trace: dump_stack (lib/dump_stack.c:52) ubsan_epilogue (lib/ubsan.c:159) __ubsan_handle_load_invalid_value (lib/ubsan.c:482) page_remove_rmap (mm/rmap.c:1084 mm/rmap.c:1096) unmap_page_range (./arch/x86/include/asm/atomic.h:27 include/linux/mm.h:463 mm/memory.c:1146 mm/memory.c:1258 mm/memory.c:1279 mm/memory.c:1303) unmap_single_vma (mm/memory.c:1348) unmap_vmas (mm/memory.c:1377 (discriminator 3)) exit_mmap (mm/mmap.c:2837) mmput (kernel/fork.c:659) do_exit (./arch/x86/include/asm/thread_info.h:168 kernel/exit.c:462 kernel/exit.c:747) do_group_exit (include/linux/sched.h:775 kernel/exit.c:873) SyS_exit_group (kernel/exit.c:901) tracesys_phase2 (arch/x86/kernel/entry_64.S:529) Fix this by using pointer parameters for both locked and flags and be more robust for future compiler changes even though the current code is implemented correctly. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix anon_vma_clone() error treatmentDaniel Forrest2014-12-03
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrew Morton noticed that the error return from anon_vma_clone() was being dropped and replaced with -ENOMEM (which is not itself a bug because the only error return value from anon_vma_clone() is -ENOMEM). I did an audit of callers of anon_vma_clone() and discovered an actual bug where the error return was being lost. In __split_vma(), between Linux 3.11 and 3.12 the code was changed so the err variable is used before the call to anon_vma_clone() and the default initial value of -ENOMEM is overwritten. So a failure of anon_vma_clone() will return success since err at this point is now zero. Below is a patch which fixes this bug and also propagates the error return value from anon_vma_clone() in all cases. Fixes: ef0855d334e1 ("mm: mempolicy: turn vma_set_policy() into vma_dup_policy()") Signed-off-by: Daniel Forrest <dan.forrest@ssec.wisc.edu> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tim Hartrick <tim@edgecast.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rmap: split out page_remove_file_rmap()Johannes Weiner2014-10-29
| | | | | | | | | | | page_remove_rmap() has too many branches on PageAnon() and is hard to follow. Move the file part into a separate function. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: fix missed end-writeback page accountingJohannes Weiner2014-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API") changed page migration to uncharge the old page right away. The page is locked, unmapped, truncated, and off the LRU, but it could race with writeback ending, which then doesn't unaccount the page properly: test_clear_page_writeback() migration wait_on_page_writeback() TestClearPageWriteback() mem_cgroup_migrate() clear PCG_USED mem_cgroup_update_page_stat() if (PageCgroupUsed(pc)) decrease memcg pages under writeback release pc->mem_cgroup->move_lock The per-page statistics interface is heavily optimized to avoid a function call and a lookup_page_cgroup() in the file unmap fast path, which means it doesn't verify whether a page is still charged before clearing PageWriteback() and it has to do it in the stat update later. Rework it so that it looks up the page's memcg once at the beginning of the transaction and then uses it throughout. The charge will be verified before clearing PageWriteback() and migration can't uncharge the page as long as that is still set. The RCU lock will protect the memcg past uncharge. As far as losing the optimization goes, the following test results are from a microbenchmark that maps, faults, and unmaps a 4GB sparse file three times in a nested fashion, so that there are two negative passes that don't account but still go through the new transaction overhead. There is no actual difference: old: 33.195102545 seconds time elapsed ( +- 0.01% ) new: 33.199231369 seconds time elapsed ( +- 0.03% ) The time spent in page_remove_rmap()'s callees still adds up to the same, but the time spent in the function itself seems reduced: # Children Self Command Shared Object Symbol old: 0.12% 0.11% filemapstress [kernel.kallsyms] [k] page_remove_rmap new: 0.12% 0.08% filemapstress [kernel.kallsyms] [k] page_remove_rmap Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: <stable@vger.kernel.org> [3.17.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert a few VM_BUG_ON callers to VM_BUG_ON_VMASasha Levin2014-10-09
| | | | | | | | | | | | | | | | | | | | Trivially convert a few VM_BUG_ON calls to VM_BUG_ON_VMA to extract more information when they trigger. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kvm: Fix page ageing bugsAndres Lagar-Cavilla2014-09-24
| | | | | | | | | | | | | | | | | | | | | 1. We were calling clear_flush_young_notify in unmap_one, but we are within an mmu notifier invalidate range scope. The spte exists no more (due to range_start) and the accessed bit info has already been propagated (due to kvm_pfn_set_accessed). Simply call clear_flush_young. 2. We clear_flush_young on a primary MMU PMD, but this may be mapped as a collection of PTEs by the secondary MMU (e.g. during log-dirty). This required expanding the interface of the clear_flush_young mmu notifier, so a lot of code has been trivially touched. 3. In the absence of shadow_accessed_mask (e.g. EPT A bit), we emulate the access bit by blowing the spte. This requires proper synchronizing with MMU notifier consumers, like every other removal of spte's does. Signed-off-by: Andres Lagar-Cavilla <andreslc@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* mm: memcontrol: rewrite uncharge APIJohannes Weiner2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The memcg uncharging code that is involved towards the end of a page's lifetime - truncation, reclaim, swapout, migration - is impressively complicated and fragile. Because anonymous and file pages were always charged before they had their page->mapping established, uncharges had to happen when the page type could still be known from the context; as in unmap for anonymous, page cache removal for file and shmem pages, and swap cache truncation for swap pages. However, these operations happen well before the page is actually freed, and so a lot of synchronization is necessary: - Charging, uncharging, page migration, and charge migration all need to take a per-page bit spinlock as they could race with uncharging. - Swap cache truncation happens during both swap-in and swap-out, and possibly repeatedly before the page is actually freed. This means that the memcg swapout code is called from many contexts that make no sense and it has to figure out the direction from page state to make sure memory and memory+swap are always correctly charged. - On page migration, the old page might be unmapped but then reused, so memcg code has to prevent untimely uncharging in that case. Because this code - which should be a simple charge transfer - is so special-cased, it is not reusable for replace_page_cache(). But now that charged pages always have a page->mapping, introduce mem_cgroup_uncharge(), which is called after the final put_page(), when we know for sure that nobody is looking at the page anymore. For page migration, introduce mem_cgroup_migrate(), which is called after the migration is successful and the new page is fully rmapped. Because the old page is no longer uncharged after migration, prevent double charges by decoupling the page's memcg association (PCG_USED and pc->mem_cgroup) from the page holding an actual charge. The new bits PCG_MEM and PCG_MEMSW represent the respective charges and are transferred to the new page during migration. mem_cgroup_migrate() is suitable for replace_page_cache() as well, which gets rid of mem_cgroup_replace_page_cache(). However, care needs to be taken because both the source and the target page can already be charged and on the LRU when fuse is splicing: grab the page lock on the charge moving side to prevent changing pc->mem_cgroup of a page under migration. Also, the lruvecs of both pages change as we uncharge the old and charge the new during migration, and putback may race with us, so grab the lru lock and isolate the pages iff on LRU to prevent races and ensure the pages are on the right lruvec afterward. Swap accounting is massively simplified: because the page is no longer uncharged as early as swap cache deletion, a new mem_cgroup_swapout() can transfer the page's memory+swap charge (PCG_MEMSW) to the swap entry before the final put_page() in page reclaim. Finally, page_cgroup changes are now protected by whatever protection the page itself offers: anonymous pages are charged under the page table lock, whereas page cache insertions, swapin, and migration hold the page lock. Uncharging happens under full exclusion with no outstanding references. Charging and uncharging also ensure that the page is off-LRU, which serializes against charge migration. Remove the very costly page_cgroup lock and set pc->flags non-atomically. [mhocko@suse.cz: mem_cgroup_charge_statistics needs preempt_disable] [vdavydov@parallels.com: fix flags definition] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Tested-by: Jet Chen <jet.chen@intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: rewrite charge APIJohannes Weiner2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These patches rework memcg charge lifetime to integrate more naturally with the lifetime of user pages. This drastically simplifies the code and reduces charging and uncharging overhead. The most expensive part of charging and uncharging is the page_cgroup bit spinlock, which is removed entirely after this series. Here are the top-10 profile entries of a stress test that reads a 128G sparse file on a freshly booted box, without even a dedicated cgroup (i.e. executing in the root memcg). Before: 15.36% cat [kernel.kallsyms] [k] copy_user_generic_string 13.31% cat [kernel.kallsyms] [k] memset 11.48% cat [kernel.kallsyms] [k] do_mpage_readpage 4.23% cat [kernel.kallsyms] [k] get_page_from_freelist 2.38% cat [kernel.kallsyms] [k] put_page 2.32% cat [kernel.kallsyms] [k] __mem_cgroup_commit_charge 2.18% kswapd0 [kernel.kallsyms] [k] __mem_cgroup_uncharge_common 1.92% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.86% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.62% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn After: 15.67% cat [kernel.kallsyms] [k] copy_user_generic_string 13.48% cat [kernel.kallsyms] [k] memset 11.42% cat [kernel.kallsyms] [k] do_mpage_readpage 3.98% cat [kernel.kallsyms] [k] get_page_from_freelist 2.46% cat [kernel.kallsyms] [k] put_page 2.13% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.88% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.67% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn 1.39% kswapd0 [kernel.kallsyms] [k] free_pcppages_bulk 1.30% cat [kernel.kallsyms] [k] kfree As you can see, the memcg footprint has shrunk quite a bit. text data bss dec hex filename 37970 9892 400 48262 bc86 mm/memcontrol.o.old 35239 9892 400 45531 b1db mm/memcontrol.o This patch (of 4): The memcg charge API charges pages before they are rmapped - i.e. have an actual "type" - and so every callsite needs its own set of charge and uncharge functions to know what type is being operated on. Worse, uncharge has to happen from a context that is still type-specific, rather than at the end of the page's lifetime with exclusive access, and so requires a lot of synchronization. Rewrite the charge API to provide a generic set of try_charge(), commit_charge() and cancel_charge() transaction operations, much like what's currently done for swap-in: mem_cgroup_try_charge() attempts to reserve a charge, reclaiming pages from the memcg if necessary. mem_cgroup_commit_charge() commits the page to the charge once it has a valid page->mapping and PageAnon() reliably tells the type. mem_cgroup_cancel_charge() aborts the transaction. This reduces the charge API and enables subsequent patches to drastically simplify uncharging. As pages need to be committed after rmap is established but before they are added to the LRU, page_add_new_anon_rmap() must stop doing LRU additions again. Revive lru_cache_add_active_or_unevictable(). [hughd@google.com: fix shmem_unuse] [hughd@google.com: Add comments on the private use of -EAGAIN] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/rmap.c: fix pgoff calculation to handle hugepage correctlyNaoya Horiguchi2014-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | I triggered VM_BUG_ON() in vma_address() when I tried to migrate an anonymous hugepage with mbind() in the kernel v3.16-rc3. This is because pgoff's calculation in rmap_walk_anon() fails to consider compound_order() only to have an incorrect value. This patch introduces page_to_pgoff(), which gets the page's offset in PAGE_CACHE_SIZE. Kirill pointed out that page cache tree should natively handle hugepages, and in order to make hugetlbfs fit it, page->index of hugetlbfs page should be in PAGE_CACHE_SIZE. This is beyond this patch, but page_to_pgoff() contains the point to be fixed in a single function. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: let mm_find_pmd fix buggy race with THP faultHugh Dickins2014-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trinity has reported: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: __lock_acquire (kernel/locking/lockdep.c:3070 (discriminator 1)) CPU: 6 PID: 16173 Comm: trinity-c364 Tainted: G W 3.15.0-rc1-next-20140415-sasha-00020-gaa90d09 #398 lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151) remove_migration_pte (mm/migrate.c:137) rmap_walk (mm/rmap.c:1628 mm/rmap.c:1699) remove_migration_ptes (mm/migrate.c:224) migrate_pages (mm/migrate.c:922 mm/migrate.c:960 mm/migrate.c:1126) migrate_misplaced_page (mm/migrate.c:1733) __handle_mm_fault (mm/memory.c:3762 mm/memory.c:3812 mm/memory.c:3925) handle_mm_fault (mm/memory.c:3948) __get_user_pages (mm/memory.c:1851) __mlock_vma_pages_range (mm/mlock.c:255) __mm_populate (mm/mlock.c:711) SyS_mlockall (include/linux/mm.h:1799 mm/mlock.c:817 mm/mlock.c:791) I believe this comes about because, whereas collapsing and splitting THP functions take anon_vma lock in write mode (which excludes concurrent rmap walks), faulting THP functions (write protection and misplaced NUMA) do not - and mostly they do not need to. But they do use a pmdp_clear_flush(), set_pmd_at() sequence which, for an instant (indeed, for a long instant, given the inter-CPU TLB flush in there), leaves *pmd neither present not trans_huge. Which can confuse a concurrent rmap walk, as when removing migration ptes, seen in the dumped trace. Although that rmap walk has a 4k page to insert, anon_vmas containing THPs are in no way segregated from 4k-page anon_vmas, so the 4k-intent mm_find_pmd() does need to cope with that instant when a trans_huge pmd is temporarily absent. I don't think we need strengthen the locking at the THP end: it's easily handled with an ACCESS_ONCE() before testing both conditions. And since mm_find_pmd() had only one caller who wanted a THP rather than a pmd, let's slightly repurpose it to fail when it hits a THP or non-present pmd, and open code split_huge_page_address() again. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: Dave Jones <davej@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'next' (accumulated 3.16 merge window patches) into masterLinus Torvalds2014-06-08
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that 3.15 is released, this merges the 'next' branch into 'master', bringing us to the normal situation where my 'master' branch is the merge window. * accumulated work in next: (6809 commits) ufs: sb mutex merge + mutex_destroy powerpc: update comments for generic idle conversion cris: update comments for generic idle conversion idle: remove cpu_idle() forward declarations nbd: zero from and len fields in NBD_CMD_DISCONNECT. mm: convert some level-less printks to pr_* MAINTAINERS: adi-buildroot-devel is moderated MAINTAINERS: add linux-api for review of API/ABI changes mm/kmemleak-test.c: use pr_fmt for logging fs/dlm/debug_fs.c: replace seq_printf by seq_puts fs/dlm/lockspace.c: convert simple_str to kstr fs/dlm/config.c: convert simple_str to kstr mm: mark remap_file_pages() syscall as deprecated mm: memcontrol: remove unnecessary memcg argument from soft limit functions mm: memcontrol: clean up memcg zoneinfo lookup mm/memblock.c: call kmemleak directly from memblock_(alloc|free) mm/mempool.c: update the kmemleak stack trace for mempool allocations lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations mm: introduce kmemleak_update_trace() mm/kmemleak.c: use %u to print ->checksum ...
| * mm/rmap.c: cleanup ttu_flagsKonstantin Khlebnikov2014-06-04
| | | | | | | | | | | | | | | | | | | | Transform action part of ttu_flags into individiual bits. These flags aren't part of any uses-space visible api or even trace events. Signed-off-by: Konstantin Khlebnikov <koct9i@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>
| * mm/rmap.c: don't call mmu_notifier_invalidate_page() during munlockKonstantin Khlebnikov2014-06-04
| | | | | | | | | | | | | | | | | | | | | | In its munmap mode, try_to_unmap_one() searches other mlocked vmas, it never unmaps pages. There is no reason for invalidation because ptes are left unchanged. Signed-off-by: Konstantin Khlebnikov <koct9i@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>
| * mm: fold mlocked_vma_newpage() into its only call siteJianyu Zhan2014-06-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In previous commit(mm: use the light version __mod_zone_page_state in mlocked_vma_newpage()) a irq-unsafe __mod_zone_page_state is used. And as suggested by Andrew, to reduce the risks that new call sites incorrectly using mlocked_vma_newpage() without knowing they are adding racing, this patch folds mlocked_vma_newpage() into its only call site, page_add_new_anon_rmap, to make it open-cocded for people to know what is going on. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: use the light version __mod_zone_page_state in mlocked_vma_newpage()Jianyu Zhan2014-06-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mlocked_vma_newpage() is called with pte lock held(a spinlock), which implies preemtion disabled, and the vm stat counter is not modified from interrupt context, so we need not use an irq-safe mod_zone_page_state() here, using a light-weight version __mod_zone_page_state() would be OK. This patch also documents __mod_zone_page_state() and some of its callsites. The comment above __mod_zone_page_state() is from Hugh Dickins, and acked by Christoph. Most credits to Hugh and Christoph for the clarification on the usage of the __mod_zone_page_state(). [akpm@linux-foundation.org: coding-style fixes] Suggested-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/rmap.c: make page_referenced_one() and try_to_unmap_one() staticKirill A. Shutemov2014-06-04
| | | | | | | | | | | | | | | | | | | | | | KSM was converted to use rmap_walk() and now nobody uses these functions outside mm/rmap.c. Let's covert them back to static. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>