Commit 3e38e0aa ("mm: memcg: charge memcg percpu memory to the
parent cgroup") adds memory tracking to the memcg kernel structures
themselves to make cgroups liable for the memory they are consuming
through the allocation of child groups (which can be significant).

This code is a bit awkward as it's spread out through several functions:
The outermost function does memalloc_use_memcg(parent) to set up
current->active_memcg, which designates which cgroup to charge, and the
inner functions pass GFP_ACCOUNT to request charging for specific
allocations.  To make sure this dependency is satisfied at all times -
to make sure we don't randomly charge whoever is calling the functions -
the inner functions warn on !current->active_memcg.

However, this triggers a false warning when the root memcg itself is
allocated.  No parent exists in this case, and so current->active_memcg
is rightfully NULL.  It's a false positive, not indicative of a bug.

Delete the warnings for now, we can revisit this later.

Fixes: 3e38e0aa ("mm: memcg: charge memcg percpu memory to the parent cgroup")
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NRoman Gushchin <guro@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull RTC updates from Alexandre Belloni:
 "Not much this cycle - mostly non urgent driver fixes:

   - ds1374: use watchdog core

   - pcf2127: add alarm and pcf2129 support"

* tag 'rtc-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: pcf2127: fix alarm handling
  rtc: pcf2127: add alarm support
  rtc: pcf2127: add pca2129 device id
  rtc: max77686: Fix wake-ups for max77620
  rtc: ds1307: provide an indication that the watchdog has fired
  rtc: ds1374: remove unused define
  rtc: ds1374: fix RTC_DRV_DS1374_WDT dependencies
  rtc: cleanup obsolete comment about struct rtc_class_ops
  rtc: pl031: fix set_alarm by adding back call to alarm_irq_enable
  rtc: ds1374: wdt: Use watchdog core for watchdog part
  rtc: Replace HTTP links with HTTPS ones
  rtc: goldfish: Enable interrupt in set_alarm() when necessary
  rtc: max77686: Do not allow interrupt to fire before system resume
  rtc: imxdi: fix trivial typos
  rtc: cpcap: fix range

Pull ceph updates from Ilya Dryomov:
 "Xiubo has completed his work on filesystem client metrics, they are
  sent to all available MDSes once per second now.

  Other than that, we have a lot of fixes and cleanups all around the
  filesystem, including a tweak to cut down on MDS request resends in
  multi-MDS setups from Yanhu and fixups for SELinux symlink labeling
  and MClientSession message decoding from Jeff"

* tag 'ceph-for-5.9-rc1' of git://github.com/ceph/ceph-client: (22 commits)
  ceph: handle zero-length feature mask in session messages
  ceph: use frag's MDS in either mode
  ceph: move sb->wb_pagevec_pool to be a global mempool
  ceph: set sec_context xattr on symlink creation
  ceph: remove redundant initialization of variable mds
  ceph: fix use-after-free for fsc->mdsc
  ceph: remove unused variables in ceph_mdsmap_decode()
  ceph: delete repeated words in fs/ceph/
  ceph: send client provided metric flags in client metadata
  ceph: periodically send perf metrics to MDSes
  ceph: check the sesion state and return false in case it is closed
  libceph: replace HTTP links with HTTPS ones
  ceph: remove unnecessary cast in kfree()
  libceph: just have osd_req_op_init() return a pointer
  ceph: do not access the kiocb after aio requests
  ceph: clean up and optimize ceph_check_delayed_caps()
  ceph: fix potential mdsc use-after-free crash
  ceph: switch to WARN_ON_ONCE in encode_supported_features()
  ceph: add global total_caps to count the mdsc's total caps number
  ceph: add check_session_state() helper and make it global
  ...

Pull more parisc updates from Helge Deller:

 - Oscar Carter contributed a patch which fixes parisc's usage of
   dereference_function_descriptor() and thus will allow using the
   -Wcast-function-type compiler option in the top-level Makefile

 - Sven Schnelle fixed a bug in the SBA code to prevent crashes during
   kexec

 - John David Anglin provided implementations for __smp_store_release()
   and __smp_load_acquire barriers() which avoids using the sync
   assembler instruction and thus speeds up barrier paths

 - Some whitespace cleanups in parisc's atomic.h header file

* 'parisc-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Implement __smp_store_release and __smp_load_acquire barriers
  parisc: mask out enable and reserved bits from sba imask
  parisc: Whitespace cleanups in atomic.h
  parisc/kernel/ftrace: Remove function callback casts
  sections.h: dereference_function_descriptor() returns void pointer

Pull more KVM updates from Paolo Bonzini:
 "PPC:
   - Improvements and bugfixes for secure VM support, giving reduced
     startup time and memory hotplug support.

   - Locking fixes in nested KVM code

   - Increase number of guests supported by HV KVM to 4094

   - Preliminary POWER10 support

  ARM:
   - Split the VHE and nVHE hypervisor code bases, build the EL2 code
     separately, allowing for the VHE code to now be built with
     instrumentation

   - Level-based TLB invalidation support

   - Restructure of the vcpu register storage to accomodate the NV code

   - Pointer Authentication available for guests on nVHE hosts

   - Simplification of the system register table parsing

   - MMU cleanups and fixes

   - A number of post-32bit cleanups and other fixes

  MIPS:
   - compilation fixes

  x86:
   - bugfixes

   - support for the SERIALIZE instruction"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (70 commits)
  KVM: MIPS/VZ: Fix build error caused by 'kvm_run' cleanup
  x86/kvm/hyper-v: Synic default SCONTROL MSR needs to be enabled
  MIPS: KVM: Convert a fallthrough comment to fallthrough
  MIPS: VZ: Only include loongson_regs.h for CPU_LOONGSON64
  x86: Expose SERIALIZE for supported cpuid
  KVM: x86: Don't attempt to load PDPTRs when 64-bit mode is enabled
  KVM: arm64: Move S1PTW S2 fault logic out of io_mem_abort()
  KVM: arm64: Don't skip cache maintenance for read-only memslots
  KVM: arm64: Handle data and instruction external aborts the same way
  KVM: arm64: Rename kvm_vcpu_dabt_isextabt()
  KVM: arm: Add trace name for ARM_NISV
  KVM: arm64: Ensure that all nVHE hyp code is in .hyp.text
  KVM: arm64: Substitute RANDOMIZE_BASE for HARDEN_EL2_VECTORS
  KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE
  KVM: PPC: Book3S HV: Rework secure mem slot dropping
  KVM: PPC: Book3S HV: Move kvmppc_svm_page_out up
  KVM: PPC: Book3S HV: Migrate hot plugged memory
  KVM: PPC: Book3S HV: In H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure-GFNs
  KVM: PPC: Book3S HV: Track the state GFNs associated with secure VMs
  KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START
  ...

Pull more clk updates from Stephen Boyd:
 "Here's some more updates that missed the last pull request because I
  happened to tag the tree at an earlier point in the history of
  clk-next. I must have fat fingered it and checked out an older version
  of clk-next on this second computer I'm using.

  This time it actually includes more code for Qualcomm SoCs, the AT91
  major updates, and some Rockchip SoC clk driver updates as well. I've
  corrected this flow so this shouldn't happen again"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (83 commits)
  clk: bcm2835: Do not use prediv with bcm2711's PLLs
  clk: drop unused function __clk_get_flags
  clk: hsdk: Fix bad dependency on IOMEM
  dt-bindings: clock: Fix YAML schemas for LPASS clocks on SC7180
  clk: mmp: avoid missing prototype warning
  clk: sparx5: Add Sparx5 SoC DPLL clock driver
  dt-bindings: clock: sparx5: Add bindings include file
  clk: qoriq: add LS1021A core pll mux options
  clk: clk-atlas6: fix return value check in atlas6_clk_init()
  clk: tegra: pll: Improve PLLM enable-state detection
  clk: X1000: Add support for calculat REFCLK of USB PHY.
  clk: JZ4780: Reformat the code to align it.
  clk: JZ4780: Add functions for enable and disable USB PHY.
  clk: Ingenic: Add RTC related clocks for Ingenic SoCs.
  dt-bindings: clock: Add tabs to align code.
  dt-bindings: clock: Add RTC related clocks for Ingenic SoCs.
  clk: davinci: Use fallthrough pseudo-keyword
  clk: imx: Use fallthrough pseudo-keyword
  clk: qcom: gcc-sdm660: Fix up gcc_mss_mnoc_bimc_axi_clk
  clk: qcom: gcc-sdm660: Add missing modem reset
  ...

Pull watchdog updates from Wim Van Sebroeck:

 - f71808e_wdt imporvements

 - dw_wdt improvements

 - mlx-wdt: support new watchdog type with longer timeout period

 - fallthrough pseudo-keyword replacements

 - overall small fixes and improvements

* tag 'linux-watchdog-5.9-rc1' of git://www.linux-watchdog.org/linux-watchdog: (35 commits)
  watchdog: rti-wdt: balance pm runtime enable calls
  watchdog: rti-wdt: attach to running watchdog during probe
  watchdog: add support for adjusting last known HW keepalive time
  watchdog: use __watchdog_ping in startup
  watchdog: softdog: Add options 'soft_reboot_cmd' and 'soft_active_on_boot'
  watchdog: pcwd_usb: remove needless check before usb_free_coherent()
  watchdog: Replace HTTP links with HTTPS ones
  dt-bindings: watchdog: renesas,wdt: Document r8a774e1 support
  watchdog: initialize device before misc_register
  watchdog: booke_wdt: Add common nowayout parameter driver
  watchdog: scx200_wdt: Use fallthrough pseudo-keyword
  watchdog: Use fallthrough pseudo-keyword
  watchdog: f71808e_wdt: do stricter parameter validation
  watchdog: f71808e_wdt: clear watchdog timeout occurred flag
  watchdog: f71808e_wdt: remove use of wrong watchdog_info option
  watchdog: f71808e_wdt: indicate WDIOF_CARDRESET support in watchdog_info.options
  docs: watchdog: codify ident.options as superset of possible status flags
  dt-bindings: watchdog: Add compatible for QCS404, SC7180, SDM845, SM8150
  dt-bindings: watchdog: Convert QCOM watchdog timer bindings to YAML
  watchdog: dw_wdt: Add DebugFS files
  ...

Pull VFIO updates from Alex Williamson:

 - Inclusive naming updates (Alex Williamson)

 - Intel X550 INTx quirk (Alex Williamson)

 - Error path resched between unmaps (Xiang Zheng)

 - SPAPR IOMMU pin_user_pages() conversion (John Hubbard)

 - Trivial mutex simplification (Alex Williamson)

 - QAT device denylist (Giovanni Cabiddu)

 - type1 IOMMU ioctl refactor (Liu Yi L)

* tag 'vfio-v5.9-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Refactor vfio_iommu_type1_ioctl()
  vfio/pci: Add QAT devices to denylist
  vfio/pci: Add device denylist
  PCI: Add Intel QuickAssist device IDs
  vfio/pci: Hold igate across releasing eventfd contexts
  vfio/spapr_tce: convert get_user_pages() --> pin_user_pages()
  vfio/type1: Add conditional rescheduling after iommu map failed
  vfio/pci: Add Intel X550 to hidden INTx devices
  vfio: Cleanup allowed driver naming

Pull drm fixes from Dave Airlie:
 "This has a few vmwgfx regression fixes we hit from the merge window
  (one in TTM), it also has a bunch of amdgpu fixes along with a
  scattering everywhere else.

  core:
   - Fix drm_dp_mst_port refcount leaks in drm_dp_mst_allocate_vcpi
   - Remove null check for kfree in drm_dev_release.
   - Fix DRM_FORMAT_MOD_AMLOGIC_FBC definition.
   - re-added docs for drm_gem_flink_ioctl()
   - add orientation quirk for ASUS T103HAF

  ttm:
   - ttm: fix page-offset calculation within TTM
   - revert patch causing vmwgfx regressions

  fbcon:
   - Fix a fbcon OOB read in fbdev, found by syzbot.

  vga:
   - Mark vga_tryget static as it's not used elsewhere.

  amdgpu:
   - Re-add spelling typo fix
   - Sienna Cichlid fixes
   - Navy Flounder fixes
   - DC fixes
   - SMU i2c fix
   - Power fixes

  vmwgfx:
   - regression fixes for modesetting crashes
   - misc fixes

  xlnx:
   - Small fixes to xlnx.

  omap:
   - Fix mode initialization in omap_connector_mode_valid().
   - force runtime PM suspend on system suspend

  tidss:
   - fix modeset init for DPI panels"

* tag 'drm-next-2020-08-12' of git://anongit.freedesktop.org/drm/drm: (70 commits)
  drm/ttm: revert "drm/ttm: make TT creation purely optional v3"
  drm/vmwgfx: fix spelling mistake "Cant" -> "Can't"
  drm/vmwgfx: fix spelling mistake "Cound" -> "Could"
  drm/vmwgfx/ldu: Use drm_mode_config_reset
  drm/vmwgfx/sou: Use drm_mode_config_reset
  drm/vmwgfx/stdu: Use drm_mode_config_reset
  drm/vmwgfx: Fix two list_for_each loop exit tests
  drm/vmwgfx: Use correct vmw_legacy_display_unit pointer
  drm/vmwgfx: Use struct_size() helper
  drm/amdgpu: Fix bug where DPM is not enabled after hibernate and resume
  drm/amd/powerplay: put VCN/JPEG into PG ungate state before dpm table setup(V3)
  drm/amd/powerplay: update swSMU VCN/JPEG PG logics
  drm/amdgpu: use mode1 reset by default for sienna_cichlid
  drm/amdgpu/smu: rework i2c adpater registration
  drm/amd/display: Display goes blank after inst
  drm/amd/display: Change null plane state swizzle mode to 4kb_s
  drm/amd/display: Use helper function to check for HDMI signal
  drm/amd/display: AMD OUI (DPCD 0x00300) skipped on some sink
  drm/amd/display: Fix logger context
  drm/amd/display: populate new dml variable
  ...

Merge more updates from Andrew Morton:

 - most of the rest of MM (memcg, hugetlb, vmscan, proc, compaction,
   mempolicy, oom-kill, hugetlbfs, migration, thp, cma, util,
   memory-hotplug, cleanups, uaccess, migration, gup, pagemap),

 - various other subsystems (alpha, misc, sparse, bitmap, lib, bitops,
   checkpatch, autofs, minix, nilfs, ufs, fat, signals, kmod, coredump,
   exec, kdump, rapidio, panic, kcov, kgdb, ipc).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits)
  mm/gup: remove task_struct pointer for all gup code
  mm: clean up the last pieces of page fault accountings
  mm/xtensa: use general page fault accounting
  mm/x86: use general page fault accounting
  mm/sparc64: use general page fault accounting
  mm/sparc32: use general page fault accounting
  mm/sh: use general page fault accounting
  mm/s390: use general page fault accounting
  mm/riscv: use general page fault accounting
  mm/powerpc: use general page fault accounting
  mm/parisc: use general page fault accounting
  mm/openrisc: use general page fault accounting
  mm/nios2: use general page fault accounting
  mm/nds32: use general page fault accounting
  mm/mips: use general page fault accounting
  mm/microblaze: use general page fault accounting
  mm/m68k: use general page fault accounting
  mm/ia64: use general page fault accounting
  mm/hexagon: use general page fault accounting
  mm/csky: use general page fault accounting
  ...

After the cleanup of page fault accounting, gup does not need to pass
task_struct around any more.  Remove that parameter in the whole gup
stack.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Here're the last pieces of page fault accounting that were still done
outside handle_mm_fault() where we still have regs==NULL when calling
handle_mm_fault():

arch/powerpc/mm/copro_fault.c:   copro_handle_mm_fault
arch/sparc/mm/fault_32.c:        force_user_fault
arch/um/kernel/trap.c:           handle_page_fault
mm/gup.c:                        faultin_page
                                 fixup_user_fault
mm/hmm.c:                        hmm_vma_fault
mm/ksm.c:                        break_ksm

Some of them has the issue of duplicated accounting for page fault
retries.  Some of them didn't do the accounting at all.

This patch cleans all these up by letting handle_mm_fault() to do per-task
page fault accounting even if regs==NULL (though we'll still skip the perf
event accountings).  With that, we can safely remove all the outliers now.

There's another functional change in that now we account the page faults
to the caller of gup, rather than the task_struct that passed into the gup
code.  More information of this can be found at [1].

After this patch, below things should never be touched again outside
handle_mm_fault():

  - task_struct.[maj|min]_flt
  - PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]

[1] https://lore.kernel.org/lkml/CAHk-=wj_V2Tps2QrMn20_W0OJF9xqNh52XSGA42s-ZJ8Y+GyKw@mail.gmail.com/Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-25-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Remove the PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN] perf events because it's
now also done in handle_mm_fault().

Move the PERF_COUNT_SW_PAGE_FAULTS event higher before taking mmap_sem for
the fault, then it'll match with the rest of the archs.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Link: http://lkml.kernel.org/r/20200707225021.200906-24-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-23-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20200707225021.200906-22-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20200707225021.200906-21-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-20-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-19-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NPekka Enberg <penberg@kernel.org>
Acked-by: NPalmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Link: http://lkml.kernel.org/r/20200707225021.200906-18-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-17-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Link: http://lkml.kernel.org/r/20200707225021.200906-16-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NStafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: http://lkml.kernel.org/r/20200707225021.200906-15-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-14-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries,
by moving it before taking mmap_sem.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NGreentime Hu <green.hu@gmail.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-13-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries,
by moving it before taking mmap_sem.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: http://lkml.kernel.org/r/20200707225021.200906-12-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Michal Simek <monstr@monstr.eu>
Link: http://lkml.kernel.org/r/20200707225021.200906-11-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-10-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-9-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NBrian Cain <bcain@codeaurora.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-8-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NGuo Ren <guoren@kernel.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-7-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.  To do this, we pass pt_regs
pointer into __do_page_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NWill Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-6-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.  To do this, we need to pass
the pt_regs pointer into __do_page_fault().

Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries,
by moving it before taking mmap_sem.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-5-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries,
by moving it before taking mmap_sem.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-4-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the general page fault accounting by passing regs into
handle_mm_fault().

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-3-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: Page fault accounting cleanups", v5.

This is v5 of the pf accounting cleanup series.  It originates from Gerald
Schaefer's report on an issue a week ago regarding to incorrect page fault
accountings for retried page fault after commit 4064b982 ("mm: allow
VM_FAULT_RETRY for multiple times"):

  https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/

What this series did:

  - Correct page fault accounting: we do accounting for a page fault
    (no matter whether it's from #PF handling, or gup, or anything else)
    only with the one that completed the fault.  For example, page fault
    retries should not be counted in page fault counters.  Same to the
    perf events.

  - Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf
    event is used in an adhoc way across different archs.

    Case (1): for many archs it's done at the entry of a page fault
    handler, so that it will also cover e.g.  errornous faults.

    Case (2): for some other archs, it is only accounted when the page
    fault is resolved successfully.

    Case (3): there're still quite some archs that have not enabled
    this perf event.

    Since this series will touch merely all the archs, we unify this
    perf event to always follow case (1), which is the one that makes most
    sense.  And since we moved the accounting into handle_mm_fault, the
    other two MAJ/MIN perf events are well taken care of naturally.

  - Unify definition of "major faults": the definition of "major
    fault" is slightly changed when used in accounting (not
    VM_FAULT_MAJOR).  More information in patch 1.

  - Always account the page fault onto the one that triggered the page
    fault.  This does not matter much for #PF handlings, but mostly for
    gup.  More information on this in patch 25.

Patchset layout:

Patch 1:     Introduced the accounting in handle_mm_fault(), not enabled.
Patch 2-23:  Enable the new accounting for arch #PF handlers one by one.
Patch 24:    Enable the new accounting for the rest outliers (gup, iommu, etc.)
Patch 25:    Cleanup GUP task_struct pointer since it's not needed any more

This patch (of 25):

This is a preparation patch to move page fault accountings into the
general code in handle_mm_fault().  This includes both the per task
flt_maj/flt_min counters, and the major/minor page fault perf events.  To
do this, the pt_regs pointer is passed into handle_mm_fault().

PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault
handlers.

So far, all the pt_regs pointer that passed into handle_mm_fault() is
NULL, which means this patch should have no intented functional change.
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com
Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a well-defined migration target allocation callback. Use it.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1596180906-8442-3-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

new_non_cma_page() in gup.c requires to allocate the new page that is not
on the CMA area.  new_non_cma_page() implements it by using allocation
scope APIs.

However, there is a work-around for hugetlb.  Normal hugetlb page
allocation API for migration is alloc_huge_page_nodemask().  It consists
of two steps.  First is dequeing from the pool.  Second is, if there is no
available page on the queue, allocating by using the page allocator.

new_non_cma_page() can't use this API since first step (deque) isn't aware
of scope API to exclude CMA area.  So, new_non_cma_page() exports hugetlb
internal function for the second step, alloc_migrate_huge_page(), to
global scope and uses it directly.  This is suboptimal since hugetlb pages
on the queue cannot be utilized.

This patch tries to fix this situation by making the deque function on
hugetlb CMA aware.  In the deque function, CMA memory is skipped if
PF_MEMALLOC_NOCMA flag is found.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMike Kravetz <mike.kravetz@oracle.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1596180906-8442-2-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have well defined scope API to exclude CMA region.  Use it rather than
manipulating gfp_mask manually.  With this change, we can now restore
__GFP_MOVABLE for gfp_mask like as usual migration target allocation.  It
would result in that the ZONE_MOVABLE is also searched by page allocator.
For hugetlb, gfp_mask is redefined since it has a regular allocation mask
filter for migration target.  __GPF_NOWARN is added to hugetlb gfp_mask
filter since a new user for gfp_mask filter, gup, want to be silent when
allocation fails.

Note that this can be considered as a fix for the commit 9a4e9f3b
("mm: update get_user_pages_longterm to migrate pages allocated from CMA
region").  However, "Fixes" tag isn't added here since it is just
suboptimal but it doesn't cause any problem.
Suggested-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Link: http://lkml.kernel.org/r/1596180906-8442-1-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a well-defined standard migration target callback.  Use it
directly.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1594622517-20681-8-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a well-defined migration target allocation callback.  Use it.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1594622517-20681-7-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>