Commit Graph

1964 Commits

Author SHA1 Message Date
Liam R. Howlett
df48a5f7a3 mm/page_alloc: reduce potential fragmentation in make_alloc_exact()
Try to avoid using the left over split page on the next request for a page
by calling __free_pages_ok() with FPI_TO_TAIL.  This increases the
potential of defragmenting memory when it's used for a short period of
time.

Link: https://lkml.kernel.org/r/20220531185626.yvlmymbxyoe5vags@revolver
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-20 21:27:23 -07:00
Linus Torvalds
5e714bf171 - Alistair Popple has a series which addresses a race which causes page
refcounting errors in ZONE_DEVICE pages.
 
 - Peter Xu fixes some userfaultfd test harness instability.
 
 - Various other patches in MM, mainly fixes.
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Merge tag 'mm-stable-2022-10-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - fix a race which causes page refcounting errors in ZONE_DEVICE pages
   (Alistair Popple)

 - fix userfaultfd test harness instability (Peter Xu)

 - various other patches in MM, mainly fixes

* tag 'mm-stable-2022-10-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (29 commits)
  highmem: fix kmap_to_page() for kmap_local_page() addresses
  mm/page_alloc: fix incorrect PGFREE and PGALLOC for high-order page
  mm/selftest: uffd: explain the write missing fault check
  mm/hugetlb: use hugetlb_pte_stable in migration race check
  mm/hugetlb: fix race condition of uffd missing/minor handling
  zram: always expose rw_page
  LoongArch: update local TLB if PTE entry exists
  mm: use update_mmu_tlb() on the second thread
  kasan: fix array-bounds warnings in tests
  hmm-tests: add test for migrate_device_range()
  nouveau/dmem: evict device private memory during release
  nouveau/dmem: refactor nouveau_dmem_fault_copy_one()
  mm/migrate_device.c: add migrate_device_range()
  mm/migrate_device.c: refactor migrate_vma and migrate_deivce_coherent_page()
  mm/memremap.c: take a pgmap reference on page allocation
  mm: free device private pages have zero refcount
  mm/memory.c: fix race when faulting a device private page
  mm/damon: use damon_sz_region() in appropriate place
  mm/damon: move sz_damon_region to damon_sz_region
  lib/test_meminit: add checks for the allocation functions
  ...
2022-10-14 12:28:43 -07:00
Yafang Shao
15cd90049d mm/page_alloc: fix incorrect PGFREE and PGALLOC for high-order page
PGFREE and PGALLOC represent the number of freed and allocated pages.  So
the page order must be considered.

Link: https://lkml.kernel.org/r/20221006101540.40686-1-laoar.shao@gmail.com
Fixes: 44042b4498 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-12 18:51:51 -07:00
Alistair Popple
ef23345089 mm: free device private pages have zero refcount
Since 27674ef6c7 ("mm: remove the extra ZONE_DEVICE struct page
refcount") device private pages have no longer had an extra reference
count when the page is in use.  However before handing them back to the
owning device driver we add an extra reference count such that free pages
have a reference count of one.

This makes it difficult to tell if a page is free or not because both free
and in use pages will have a non-zero refcount.  Instead we should return
pages to the drivers page allocator with a zero reference count.  Kernel
code can then safely use kernel functions such as get_page_unless_zero().

Link: https://lkml.kernel.org/r/cf70cf6f8c0bdb8aaebdbfb0d790aea4c683c3c6.1664366292.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-12 18:51:49 -07:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Linus Torvalds
ef688f8b8c The first batch of KVM patches, mostly covering x86, which I
am sending out early due to me travelling next week.  There is a
 lone mm patch for which Andrew gave an informal ack at
 https://lore.kernel.org/linux-mm/20220817102500.440c6d0a3fce296fdf91bea6@linux-foundation.org.
 
 I will send the bulk of ARM work, as well as other
 architectures, at the end of next week.
 
 ARM:
 
 * Account stage2 page table allocations in memory stats.
 
 x86:
 
 * Account EPT/NPT arm64 page table allocations in memory stats.
 
 * Tracepoint cleanups/fixes for nested VM-Enter and emulated MSR accesses.
 
 * Drop eVMCS controls filtering for KVM on Hyper-V, all known versions of
   Hyper-V now support eVMCS fields associated with features that are
   enumerated to the guest.
 
 * Use KVM's sanitized VMCS config as the basis for the values of nested VMX
   capabilities MSRs.
 
 * A myriad event/exception fixes and cleanups.  Most notably, pending
   exceptions morph into VM-Exits earlier, as soon as the exception is
   queued, instead of waiting until the next vmentry.  This fixed
   a longstanding issue where the exceptions would incorrecly become
   double-faults instead of triggering a vmexit; the common case of
   page-fault vmexits had a special workaround, but now it's fixed
   for good.
 
 * A handful of fixes for memory leaks in error paths.
 
 * Cleanups for VMREAD trampoline and VMX's VM-Exit assembly flow.
 
 * Never write to memory from non-sleepable kvm_vcpu_check_block()
 
 * Selftests refinements and cleanups.
 
 * Misc typo cleanups.
 
 Generic:
 
 * remove KVM_REQ_UNHALT
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "The first batch of KVM patches, mostly covering x86.

  ARM:

   - Account stage2 page table allocations in memory stats

  x86:

   - Account EPT/NPT arm64 page table allocations in memory stats

   - Tracepoint cleanups/fixes for nested VM-Enter and emulated MSR
     accesses

   - Drop eVMCS controls filtering for KVM on Hyper-V, all known
     versions of Hyper-V now support eVMCS fields associated with
     features that are enumerated to the guest

   - Use KVM's sanitized VMCS config as the basis for the values of
     nested VMX capabilities MSRs

   - A myriad event/exception fixes and cleanups. Most notably, pending
     exceptions morph into VM-Exits earlier, as soon as the exception is
     queued, instead of waiting until the next vmentry. This fixed a
     longstanding issue where the exceptions would incorrecly become
     double-faults instead of triggering a vmexit; the common case of
     page-fault vmexits had a special workaround, but now it's fixed for
     good

   - A handful of fixes for memory leaks in error paths

   - Cleanups for VMREAD trampoline and VMX's VM-Exit assembly flow

   - Never write to memory from non-sleepable kvm_vcpu_check_block()

   - Selftests refinements and cleanups

   - Misc typo cleanups

  Generic:

   - remove KVM_REQ_UNHALT"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits)
  KVM: remove KVM_REQ_UNHALT
  KVM: mips, x86: do not rely on KVM_REQ_UNHALT
  KVM: x86: never write to memory from kvm_vcpu_check_block()
  KVM: x86: Don't snapshot pending INIT/SIPI prior to checking nested events
  KVM: nVMX: Make event request on VMXOFF iff INIT/SIPI is pending
  KVM: nVMX: Make an event request if INIT or SIPI is pending on VM-Enter
  KVM: SVM: Make an event request if INIT or SIPI is pending when GIF is set
  KVM: x86: lapic does not have to process INIT if it is blocked
  KVM: x86: Rename kvm_apic_has_events() to make it INIT/SIPI specific
  KVM: x86: Rename and expose helper to detect if INIT/SIPI are allowed
  KVM: nVMX: Make an event request when pending an MTF nested VM-Exit
  KVM: x86: make vendor code check for all nested events
  mailmap: Update Oliver's email address
  KVM: x86: Allow force_emulation_prefix to be written without a reload
  KVM: selftests: Add an x86-only test to verify nested exception queueing
  KVM: selftests: Use uapi header to get VMX and SVM exit reasons/codes
  KVM: x86: Rename inject_pending_events() to kvm_check_and_inject_events()
  KVM: VMX: Update MTF and ICEBP comments to document KVM's subtle behavior
  KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions
  KVM: x86: Morph pending exceptions to pending VM-Exits at queue time
  ...
2022-10-09 09:39:55 -07:00
Ran Xiaokai
a57ae9ef9e mm/page_alloc: update comments for rmqueue()
Since commit 44042b4498 ("mm/page_alloc: allow high-order pages to be
stored on the per-cpu lists"), the per-cpu page allocators (PCP) is not
only for order-0 pages.  Update the comments.

Link: https://lkml.kernel.org/r/20220918025640.208586-1-ran.xiaokai@zte.com.cn
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:31 -07:00
Miaohe Lin
c9b3637f8a mm/page_alloc: fix obsolete comment in deferred_pfn_valid()
There are no architectures that can have holes in the memory map within a
pageblock since commit 859a85ddf9 ("mm: remove pfn_valid_within() and
CONFIG_HOLES_IN_ZONE").  Update the corresponding comment.

Link: https://lkml.kernel.org/r/20220916072257.9639-17-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:30 -07:00
Miaohe Lin
896c4d5253 mm/page_alloc: use costly_order in WARN_ON_ONCE_GFP()
There's no need to check whether order > PAGE_ALLOC_COSTLY_ORDER again. 
Minor readability improvement.

Link: https://lkml.kernel.org/r/20220916072257.9639-15-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:30 -07:00
Miaohe Lin
dae37a5dcc mm/page_alloc: init local variable buddy_pfn
The local variable buddy_pfn could be passed to buddy_merge_likely()
without initialization if the passed in order is MAX_ORDER - 1.  This
looks buggy but buddy_pfn won't be used in this case as there's a order >=
MAX_ORDER - 2 check.  Init buddy_pfn to 0 anyway to avoid possible future
misuse.

Link: https://lkml.kernel.org/r/20220916072257.9639-14-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:30 -07:00
Miaohe Lin
c940e0207a mm/page_alloc: use helper macro SZ_1{K,M}
Use helper macro SZ_1K and SZ_1M to do the size conversion.  Minor
readability improvement.

Link: https://lkml.kernel.org/r/20220916072257.9639-13-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:30 -07:00
Miaohe Lin
6dc2c87a5a mm/page_alloc: make boot_nodestats static
It's only used in mm/page_alloc.c now.  Make it static.

Link: https://lkml.kernel.org/r/20220916072257.9639-12-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:30 -07:00
Miaohe Lin
c035290424 mm/page_alloc: use local variable zone_idx directly
Use local variable zone_idx directly since it holds the exact value of
zone_idx().  No functional change intended.

Link: https://lkml.kernel.org/r/20220916072257.9639-10-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:29 -07:00
Miaohe Lin
b36184553d mm/page_alloc: add missing is_migrate_isolate() check in set_page_guard()
In MIGRATE_ISOLATE case, zone freepage state shouldn't be modified as
caller will take care of it.  Add missing is_migrate_isolate() here to
avoid possible unbalanced freepage state.  This would happen if someone
isolates the block, and then we face an MCE failure/soft-offline on a page
within that block.  __mod_zone_freepage_state() will be triggered via
below call trace which already had been triggered back when block was
isolated:

take_page_off_buddy
  break_down_buddy_pages
    set_page_guard

Link: https://lkml.kernel.org/r/20220916072257.9639-9-linmiaohe@huawei.com
Fixes: 06be6ff3d2 ("mm,hwpoison: rework soft offline for free pages")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:29 -07:00
Miaohe Lin
022e7fa0f7 mm/page_alloc: fix freeing static percpu memory
The size of struct per_cpu_zonestat can be 0 on !SMP && !NUMA.  In that
case, zone->per_cpu_zonestats will always equal to boot_zonestats.  But in
zone_pcp_reset(), zone->per_cpu_zonestats is freed via free_percpu()
directly without checking against boot_zonestats first.  boot_zonestats
will be released by free_percpu() unexpectedly.

Link: https://lkml.kernel.org/r/20220916072257.9639-7-linmiaohe@huawei.com
Fixes: 28f836b677 ("mm/page_alloc: split per cpu page lists and zone stats")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:29 -07:00
Miaohe Lin
5749fcc5f0 mm/page_alloc: add __init annotations to init_mem_debugging_and_hardening()
It's only called by mm_init(). Add __init annotations to it.

Link: https://lkml.kernel.org/r/20220916072257.9639-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:28 -07:00
Miaohe Lin
709924bc75 mm/page_alloc: remove obsolete comment in zone_statistics()
Since commit 43c95bcc51 ("mm/page_alloc: reduce duration that IRQs are
disabled for VM counters"), zone_statistics() is not called with
interrupts disabled.  Update the corresponding comment.

Link: https://lkml.kernel.org/r/20220916072257.9639-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:28 -07:00
Miaohe Lin
638a9ae97a mm: remove obsolete macro NR_PCP_ORDER_MASK and NR_PCP_ORDER_WIDTH
Since commit 8b10b465d0 ("mm/page_alloc: free pages in a single pass
during bulk free"), they're not used anymore.  Remove them.

Link: https://lkml.kernel.org/r/20220916072257.9639-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:28 -07:00
Miaohe Lin
b89f173516 mm/page_alloc: make zone_pcp_update() static
Since commit b92ca18e8c ("mm/page_alloc: disassociate the pcp->high from
pcp->batch"), zone_pcp_update() is only used in mm/page_alloc.c.  Move
zone_pcp_update() up to avoid forward declaration and then make it static.
No functional change intended.

Link: https://lkml.kernel.org/r/20220916072257.9639-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:28 -07:00
Miaohe Lin
ce96fa6223 mm/page_alloc: ensure kswapd doesn't accidentally go to sleep
Patch series "A few cleanup patches for mm", v2.

This series contains a few cleanup patches to remove the obsolete comments
and functions, use helper macro to improve readability and so on.  More
details can be found in the respective changelogs.


This patch (of 16):

If ALLOC_KSWAPD is set, wake_all_kswapds() will be called to ensure kswapd
doesn't accidentally go to sleep.  But when reserve_flags is set,
alloc_flags will be overwritten and ALLOC_KSWAPD is thus lost.  Preserve
the ALLOC_KSWAPD flag in alloc_flags to ensure kswapd won't go to sleep
accidentally.

Link: https://lkml.kernel.org/r/20220916072257.9639-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220916072257.9639-2-linmiaohe@huawei.com
Fixes: 0a79cdad5e ("mm: use alloc_flags to record if kswapd can wake")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:28 -07:00
Alexander Potapenko
42eaa27d9e security: kmsan: fix interoperability with auto-initialization
Heap and stack initialization is great, but not when we are trying uses of
uninitialized memory.  When the kernel is built with KMSAN, having kernel
memory initialization enabled may introduce false negatives.

We disable CONFIG_INIT_STACK_ALL_PATTERN and CONFIG_INIT_STACK_ALL_ZERO
under CONFIG_KMSAN, making it impossible to auto-initialize stack
variables in KMSAN builds.  We also disable
CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON to
prevent accidental use of heap auto-initialization.

We however still let the users enable heap auto-initialization at
boot-time (by setting init_on_alloc=1 or init_on_free=1), in which case a
warning is printed.

Link: https://lkml.kernel.org/r/20220915150417.722975-31-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:23 -07:00
Alexander Potapenko
3c20650982 init: kmsan: call KMSAN initialization routines
kmsan_init_shadow() scans the mappings created at boot time and creates
metadata pages for those mappings.

When the memblock allocator returns pages to pagealloc, we reserve 2/3 of
those pages and use them as metadata for the remaining 1/3.  Once KMSAN
starts, every page allocated by pagealloc has its associated shadow and
origin pages.

kmsan_initialize() initializes the bookkeeping for init_task and enables
KMSAN.

Link: https://lkml.kernel.org/r/20220915150417.722975-18-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:21 -07:00
Alexander Potapenko
b073d7f8ae mm: kmsan: maintain KMSAN metadata for page operations
Insert KMSAN hooks that make the necessary bookkeeping changes:
 - poison page shadow and origins in alloc_pages()/free_page();
 - clear page shadow and origins in clear_page(), copy_user_highpage();
 - copy page metadata in copy_highpage(), wp_page_copy();
 - handle vmap()/vunmap()/iounmap();

Link: https://lkml.kernel.org/r/20220915150417.722975-15-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:20 -07:00
Andrew Morton
d452289fcd mm/page_alloc.c: document bulkfree_pcp_prepare() return value
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: ke.wang <ke.wang@unisoc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Zhaoyang Huang <huangzhaoyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:14 -07:00
Andrew Morton
a8368cd8e2 mm/page_alloc.c: rename check_free_page() to free_page_is_bad()
The name "check_free_page()" provides no information regarding its return
value when the page is indeed found to be bad.

Renaming it to "free_page_is_bad()" makes it clear that a `true' return
value means the page was bad.

And make it return a bool, not an int.

[akpm@linux-foundation.org: don't use bool as int]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: ke.wang <ke.wang@unisoc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Zhaoyang Huang <huangzhaoyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:14 -07:00
Kefeng Wang
ee0913c471 mm: add pageblock_aligned() macro
Add pageblock_aligned() and use it to simplify code.

Link: https://lkml.kernel.org/r/20220907060844.126891-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:04 -07:00
Kefeng Wang
4f9bc69ac5 mm: reuse pageblock_start/end_pfn() macro
Move pageblock_start_pfn/pageblock_end_pfn() into pageblock-flags.h, then
they could be used somewhere else, not only in compaction, also use
ALIGN_DOWN() instead of round_down() to be pair with ALIGN(), which should
be same for pageblock usage.

Link: https://lkml.kernel.org/r/20220907060844.126891-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:03 -07:00
Michal Hocko
974f4367dd mm: reduce noise in show_mem for lowmem allocations
While discussing early DMA pool pre-allocation failure with Christoph [1]
I have realized that the allocation failure warning is rather noisy for
constrained allocations like GFP_DMA{32}.  Those zones are usually not
populated on all nodes very often as their memory ranges are constrained.

This is an attempt to reduce the ballast that doesn't provide any relevant
information for those allocation failures investigation.  Please note that
I have only compile tested it (in my default config setup) and I am
throwing it mostly to see what people think about it.

[1] http://lkml.kernel.org/r/20220817060647.1032426-1-hch@lst.de

[mhocko@suse.com: update]
  Link: https://lkml.kernel.org/r/Yw29bmJTIkKogTiW@dhcp22.suse.cz
[mhocko@suse.com: fix build]
[akpm@linux-foundation.org: fix it for mapletree]
[akpm@linux-foundation.org: update it for Michal's update]
[mhocko@suse.com: fix arch/powerpc/xmon/xmon.c]
  Link: https://lkml.kernel.org/r/Ywh3C4dKB9B93jIy@dhcp22.suse.cz
[akpm@linux-foundation.org: fix arch/sparc/kernel/setup_32.c]
Link: https://lkml.kernel.org/r/YwScVmVofIZkopkF@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:29 -07:00
Andrew Morton
6d751329e7 Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
Maurizio Lombardi
dac22531bb mm: prevent page_frag_alloc() from corrupting the memory
A number of drivers call page_frag_alloc() with a fragment's size >
PAGE_SIZE.

In low memory conditions, __page_frag_cache_refill() may fail the order
3 cache allocation and fall back to order 0; In this case, the cache
will be smaller than the fragment, causing memory corruptions.

Prevent this from happening by checking if the newly allocated cache is
large enough for the fragment; if not, the allocation will fail and
page_frag_alloc() will return NULL.

Link: https://lkml.kernel.org/r/20220715125013.247085-1-mlombard@redhat.com
Fixes: b63ae8ca09 ("mm/net: Rename and move page fragment handling from net/ to mm/")
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Cc: Chen Lin <chen45464546@163.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Kefeng Wang
9a157dd8fe mm: remove BUG_ON() in __isolate_free_page()
Drop unneed comment and blank, adjust the variable, and the most important
is to delete BUG_ON().  The page passed is always buddy page into
__isolate_free_page() from compaction, page_isolation and page_reporting,
and the caller also check the return, BUG_ON() is a too drastic measure,
remove it.

Link: https://lkml.kernel.org/r/20220901015043.189276-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:11 -07:00
zezuo
663d0cfd2e mm/page_alloc.c: delete a redundant parameter of rmqueue_pcplist
The gfp_flags parameter is not used in rmqueue_pcplist, so directly delete
this parameter.

Link: https://lkml.kernel.org/r/20220831013404.3360714-1-zuoze1@huawei.com
Signed-off-by: zezuo <zuoze1@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:05 -07:00
Kefeng Wang
b4a0215e11 mm: fix null-ptr-deref in kswapd_is_running()
kswapd_run/stop() will set pgdat->kswapd to NULL, which could race with
kswapd_is_running() in kcompactd(),

kswapd_run/stop()                       kcompactd()
                                          kswapd_is_running()
  pgdat->kswapd // error or nomal ptr
                                          verify pgdat->kswapd
                                            // load non-NULL
pgdat->kswapd
  pgdat->kswapd = NULL
                                          task_is_running(pgdat->kswapd)
                                            // Null pointer derefence

KASAN reports the null-ptr-deref shown below,

  vmscan: Failed to start kswapd on node 0
  ...
  BUG: KASAN: null-ptr-deref in kcompactd+0x440/0x504
  Read of size 8 at addr 0000000000000024 by task kcompactd0/37

  CPU: 0 PID: 37 Comm: kcompactd0 Kdump: loaded Tainted: G           OE     5.10.60 #1
  Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
  Call trace:
   dump_backtrace+0x0/0x394
   show_stack+0x34/0x4c
   dump_stack+0x158/0x1e4
   __kasan_report+0x138/0x140
   kasan_report+0x44/0xdc
   __asan_load8+0x94/0xd0
   kcompactd+0x440/0x504
   kthread+0x1a4/0x1f0
   ret_from_fork+0x10/0x18

At present kswapd/kcompactd_run() and kswapd/kcompactd_stop() are protected
by mem_hotplug_begin/done(), but without kcompactd(). There is no need to
involve memory hotplug lock in kcompactd(), so let's add a new mutex to
protect pgdat->kswapd accesses.

Also, because the kcompactd task will check the state of kswapd task, it's
better to call kcompactd_stop() before kswapd_stop() to reduce lock
conflicts.

[akpm@linux-foundation.org: add comments]
Link: https://lkml.kernel.org/r/20220827111959.186838-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:04 -07:00
Li Zhe
c4f20f1479 page_ext: introduce boot parameter 'early_page_ext'
In commit 2f1ee0913c ("Revert "mm: use early_pfn_to_nid in
page_ext_init""), we call page_ext_init() after page_alloc_init_late() to
avoid some panic problem.  It seems that we cannot track early page
allocations in current kernel even if page structure has been initialized
early.

This patch introduces a new boot parameter 'early_page_ext' to resolve
this problem.  If we pass it to the kernel, page_ext_init() will be moved
up and the feature 'deferred initialization of struct pages' will be
disabled to initialize the page allocator early and prevent the panic
problem above.  It can help us to catch early page allocations.  This is
useful especially when we find that the free memory value is not the same
right after different kernel booting.

[akpm@linux-foundation.org: fix section issue by removing __meminitdata]
Link: https://lkml.kernel.org/r/20220825102714.669-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:02 -07:00
Kefeng Wang
fb70c4878d mm: kill find_min_pfn_with_active_regions()
find_min_pfn_with_active_regions() is only called from free_area_init(). 
Open-code the PHYS_PFN(memblock_start_of_DRAM()) into free_area_init(),
and kill find_min_pfn_with_active_regions().

Link: https://lkml.kernel.org/r/20220815111017.39341-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:56 -07:00
Abel Wu
e933dc4a07 mm/page_alloc: only search higher order when fallback
It seems unnecessary to search pages with order < alloc_order in
fallback allocation.

This can currently happen with ALLOC_NOFRAGMENT and alloc_order >
pageblock_order, so add a test to prevent it.

[vbabka@suse.cz: changelog addition]
Link: https://lkml.kernel.org/r/20220803025121.47018-1-wuyun.abel@bytedance.com
Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:51 -07:00
Li kunyu
97bab178e8 page_alloc: remove inactive initialization
The allocation address of the table pointer variable is first performed in
the function, no initialization assignment is required, and no invalid
pointer will appear.

Link: https://lkml.kernel.org/r/20220803064118.3664-1-kunyu@nfschina.com
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:50 -07:00
Mel Gorman
3d36424b3b mm/page_alloc: fix race condition between build_all_zonelists and page allocation
Patrick Daly reported the following problem;

	NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK] - before offline operation
	[0] - ZONE_MOVABLE
	[1] - ZONE_NORMAL
	[2] - NULL

	For a GFP_KERNEL allocation, alloc_pages_slowpath() will save the
	offset of ZONE_NORMAL in ac->preferred_zoneref. If a concurrent
	memory_offline operation removes the last page from ZONE_MOVABLE,
	build_all_zonelists() & build_zonerefs_node() will update
	node_zonelists as shown below. Only populated zones are added.

	NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK] - after offline operation
	[0] - ZONE_NORMAL
	[1] - NULL
	[2] - NULL

The race is simple -- page allocation could be in progress when a memory
hot-remove operation triggers a zonelist rebuild that removes zones.  The
allocation request will still have a valid ac->preferred_zoneref that is
now pointing to NULL and triggers an OOM kill.

This problem probably always existed but may be slightly easier to trigger
due to 6aa303defb ("mm, vmscan: only allocate and reclaim from zones
with pages managed by the buddy allocator") which distinguishes between
zones that are completely unpopulated versus zones that have valid pages
not managed by the buddy allocator (e.g.  reserved, memblock, ballooning
etc).  Memory hotplug had multiple stages with timing considerations
around managed/present page updates, the zonelist rebuild and the zone
span updates.  As David Hildenbrand puts it

	memory offlining adjusts managed+present pages of the zone
	essentially in one go. If after the adjustments, the zone is no
	longer populated (present==0), we rebuild the zone lists.

	Once that's done, we try shrinking the zone (start+spanned
	pages) -- which results in zone_start_pfn == 0 if there are no
	more pages. That happens *after* rebuilding the zonelists via
	remove_pfn_range_from_zone().

The only requirement to fix the race is that a page allocation request
identifies when a zonelist rebuild has happened since the allocation
request started and no page has yet been allocated.  Use a seqlock_t to
track zonelist updates with a lockless read-side of the zonelist and
protecting the rebuild and update of the counter with a spinlock.

[akpm@linux-foundation.org: make zonelist_update_seq static]
Link: https://lkml.kernel.org/r/20220824110900.vh674ltxmzb3proq@techsingularity.net
Fixes: 6aa303defb ("mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Patrick Daly <quic_pdaly@quicinc.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>	[4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 16:22:29 -07:00
Yosry Ahmed
ebc97a52b5 mm: add NR_SECONDARY_PAGETABLE to count secondary page table uses.
We keep track of several kernel memory stats (total kernel memory, page
tables, stack, vmalloc, etc) on multiple levels (global, per-node,
per-memcg, etc). These stats give insights to users to how much memory
is used by the kernel and for what purposes.

Currently, memory used by KVM mmu is not accounted in any of those
kernel memory stats. This patch series accounts the memory pages
used by KVM for page tables in those stats in a new
NR_SECONDARY_PAGETABLE stat. This stat can be later extended to account
for other types of secondary pages tables (e.g. iommu page tables).

KVM has a decent number of large allocations that aren't for page
tables, but for most of them, the number/size of those allocations
scales linearly with either the number of vCPUs or the amount of memory
assigned to the VM. KVM's secondary page table allocations do not scale
linearly, especially when nested virtualization is in use.

From a KVM perspective, NR_SECONDARY_PAGETABLE will scale with KVM's
per-VM pages_{4k,2m,1g} stats unless the guest is doing something
bizarre (e.g. accessing only 4kb chunks of 2mb pages so that KVM is
forced to allocate a large number of page tables even though the guest
isn't accessing that much memory). However, someone would need to either
understand how KVM works to make that connection, or know (or be told) to
go look at KVM's stats if they're running VMs to better decipher the stats.

Furthermore, having NR_PAGETABLE side-by-side with NR_SECONDARY_PAGETABLE
is informative. For example, when backing a VM with THP vs. HugeTLB,
NR_SECONDARY_PAGETABLE is roughly the same, but NR_PAGETABLE is an order
of magnitude higher with THP. So having this stat will at the very least
prove to be useful for understanding tradeoffs between VM backing types,
and likely even steer folks towards potential optimizations.

The original discussion with more details about the rationale:
https://lore.kernel.org/all/87ilqoi77b.wl-maz@kernel.org

This stat will be used by subsequent patches to count KVM mmu
memory usage.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220823004639.2387269-2-yosryahmed@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2022-08-24 13:51:42 -07:00
Linus Torvalds
6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Linus Torvalds
97a77ab14f EFI updates for v5.20
- Enable mirrored memory for arm64
 - Fix up several abuses of the efivar API
 - Refactor the efivar API in preparation for moving the 'business logic'
   part of it into efivarfs
 - Enable ACPI PRM on arm64
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Merge tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:

 - Enable mirrored memory for arm64

 - Fix up several abuses of the efivar API

 - Refactor the efivar API in preparation for moving the 'business
   logic' part of it into efivarfs

 - Enable ACPI PRM on arm64

* tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  ACPI: Move PRM config option under the main ACPI config
  ACPI: Enable Platform Runtime Mechanism(PRM) support on ARM64
  ACPI: PRM: Change handler_addr type to void pointer
  efi: Simplify arch_efi_call_virt() macro
  drivers: fix typo in firmware/efi/memmap.c
  efi: vars: Drop __efivar_entry_iter() helper which is no longer used
  efi: vars: Use locking version to iterate over efivars linked lists
  efi: pstore: Omit efivars caching EFI varstore access layer
  efi: vars: Add thin wrapper around EFI get/set variable interface
  efi: vars: Don't drop lock in the middle of efivar_init()
  pstore: Add priv field to pstore_record for backend specific use
  Input: applespi - avoid efivars API and invoke EFI services directly
  selftests/kexec: remove broken EFI_VARS secure boot fallback check
  brcmfmac: Switch to appropriate helper to load EFI variable contents
  iwlwifi: Switch to proper EFI variable store interface
  media: atomisp_gmin_platform: stop abusing efivar API
  efi: efibc: avoid efivar API for setting variables
  efi: avoid efivars layer when loading SSDTs from variables
  efi: Correct comment on efi_memmap_alloc
  memblock: Disable mirror feature if kernelcore is not specified
  ...
2022-08-03 14:38:02 -07:00
Linus Torvalds
0cec3f24a7 arm64 updates for 5.20
- Remove unused generic cpuidle support (replaced by PSCI version)
 
 - Fix documentation describing the kernel virtual address space
 
 - Handling of some new CPU errata in Arm implementations
 
 - Rework of our exception table code in preparation for handling
   machine checks (i.e. RAS errors) more gracefully
 
 - Switch over to the generic implementation of ioremap()
 
 - Fix lockdep tracking in NMI context
 
 - Instrument our memory barrier macros for KCSAN
 
 - Rework of the kPTI G->nG page-table repainting so that the MMU remains
   enabled and the boot time is no longer slowed to a crawl for systems
   which require the late remapping
 
 - Enable support for direct swapping of 2MiB transparent huge-pages on
   systems without MTE
 
 - Fix handling of MTE tags with allocating new pages with HW KASAN
 
 - Expose the SMIDR register to userspace via sysfs
 
 - Continued rework of the stack unwinder, particularly improving the
   behaviour under KASAN
 
 - More repainting of our system register definitions to match the
   architectural terminology
 
 - Improvements to the layout of the vDSO objects
 
 - Support for allocating additional bits of HWCAP2 and exposing
   FEAT_EBF16 to userspace on CPUs that support it
 
 - Considerable rework and optimisation of our early boot code to reduce
   the need for cache maintenance and avoid jumping in and out of the
   kernel when handling relocation under KASLR
 
 - Support for disabling SVE and SME support on the kernel command-line
 
 - Support for the Hisilicon HNS3 PMU
 
 - Miscellanous cleanups, trivial updates and minor fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Highlights include a major rework of our kPTI page-table rewriting
  code (which makes it both more maintainable and considerably faster in
  the cases where it is required) as well as significant changes to our
  early boot code to reduce the need for data cache maintenance and
  greatly simplify the KASLR relocation dance.

  Summary:

   - Remove unused generic cpuidle support (replaced by PSCI version)

   - Fix documentation describing the kernel virtual address space

   - Handling of some new CPU errata in Arm implementations

   - Rework of our exception table code in preparation for handling
     machine checks (i.e. RAS errors) more gracefully

   - Switch over to the generic implementation of ioremap()

   - Fix lockdep tracking in NMI context

   - Instrument our memory barrier macros for KCSAN

   - Rework of the kPTI G->nG page-table repainting so that the MMU
     remains enabled and the boot time is no longer slowed to a crawl
     for systems which require the late remapping

   - Enable support for direct swapping of 2MiB transparent huge-pages
     on systems without MTE

   - Fix handling of MTE tags with allocating new pages with HW KASAN

   - Expose the SMIDR register to userspace via sysfs

   - Continued rework of the stack unwinder, particularly improving the
     behaviour under KASAN

   - More repainting of our system register definitions to match the
     architectural terminology

   - Improvements to the layout of the vDSO objects

   - Support for allocating additional bits of HWCAP2 and exposing
     FEAT_EBF16 to userspace on CPUs that support it

   - Considerable rework and optimisation of our early boot code to
     reduce the need for cache maintenance and avoid jumping in and out
     of the kernel when handling relocation under KASLR

   - Support for disabling SVE and SME support on the kernel
     command-line

   - Support for the Hisilicon HNS3 PMU

   - Miscellanous cleanups, trivial updates and minor fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (136 commits)
  arm64: Delay initialisation of cpuinfo_arm64::reg_{zcr,smcr}
  arm64: fix KASAN_INLINE
  arm64/hwcap: Support FEAT_EBF16
  arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long
  arm64/hwcap: Document allocation of upper bits of AT_HWCAP
  arm64: enable THP_SWAP for arm64
  arm64/mm: use GENMASK_ULL for TTBR_BADDR_MASK_52
  arm64: errata: Remove AES hwcap for COMPAT tasks
  arm64: numa: Don't check node against MAX_NUMNODES
  drivers/perf: arm_spe: Fix consistency of SYS_PMSCR_EL1.CX
  perf: RISC-V: Add of_node_put() when breaking out of for_each_of_cpu_node()
  docs: perf: Include hns3-pmu.rst in toctree to fix 'htmldocs' WARNING
  arm64: kasan: Revert "arm64: mte: reset the page tag in page->flags"
  mm: kasan: Skip page unpoisoning only if __GFP_SKIP_KASAN_UNPOISON
  mm: kasan: Skip unpoisoning of user pages
  mm: kasan: Ensure the tags are visible before the tag in page->flags
  drivers/perf: hisi: add driver for HNS3 PMU
  drivers/perf: hisi: Add description for HNS3 PMU driver
  drivers/perf: riscv_pmu_sbi: perf format
  perf/arm-cci: Use the bitmap API to allocate bitmaps
  ...
2022-08-01 10:37:00 -07:00
Mark-PK Tsai
189cdcfeef mm/page_alloc: correct the wrong cpuset file path in comment
cpuset.c was moved to kernel/cgroup/ in below commit
201af4c0fa ("cgroup: move cgroup files under kernel/cgroup/")
Correct the wrong path in comment.

Link: https://lkml.kernel.org/r/20220718120336.5145-1-mark-pk.tsai@mediatek.com
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:07:16 -07:00
Jaewon Kim
9282012fc0 page_alloc: fix invalid watermark check on a negative value
There was a report that a task is waiting at the
throttle_direct_reclaim. The pgscan_direct_throttle in vmstat was
increasing.

This is a bug where zone_watermark_fast returns true even when the free
is very low. The commit f27ce0e140 ("page_alloc: consider highatomic
reserve in watermark fast") changed the watermark fast to consider
highatomic reserve. But it did not handle a negative value case which
can be happened when reserved_highatomic pageblock is bigger than the
actual free.

If watermark is considered as ok for the negative value, allocating
contexts for order-0 will consume all free pages without direct reclaim,
and finally free page may become depleted except highatomic free.

Then allocating contexts may fall into throttle_direct_reclaim. This
symptom may easily happen in a system where wmark min is low and other
reclaimers like kswapd does not make free pages quickly.

Handle the negative case by using MIN.

Link: https://lkml.kernel.org/r/20220725095212.25388-1-jaewon31.kim@samsung.com
Fixes: f27ce0e140 ("page_alloc: consider highatomic reserve in watermark fast")
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Reported-by: GyeongHwan Hong <gh21.hong@samsung.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Yong-Taek Lee <ytk.lee@samsung.com>
Cc: <stable@vger.kerenl.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 11:33:37 -07:00
Uros Bizjak
04ec006171 mm/page_alloc: use try_cmpxchg in set_pfnblock_flags_mask
Use try_cmpxchg instead of cmpxchg in set_pfnblock_flags_mask.  x86
CMPXCHG instruction returns success in ZF flag, so this change saves a
compare after cmpxchg (and related move instruction in front of cmpxchg). 
The main loop improves from:

    1c5d:	48 89 c2             	mov    %rax,%rdx
    1c60:	48 89 c1             	mov    %rax,%rcx
    1c63:	48 21 fa             	and    %rdi,%rdx
    1c66:	4c 09 c2             	or     %r8,%rdx
    1c69:	f0 48 0f b1 16       	lock cmpxchg %rdx,(%rsi)
    1c6e:	48 39 c1             	cmp    %rax,%rcx
    1c71:	75 ea                	jne    1c5d <...>

to:

    1c60:	48 89 ca             	mov    %rcx,%rdx
    1c63:	48 21 c2             	and    %rax,%rdx
    1c66:	4c 09 c2             	or     %r8,%rdx
    1c69:	f0 48 0f b1 16       	lock cmpxchg %rdx,(%rsi)
    1c6e:	75 f0                	jne    1c60 <...>

Link: https://lkml.kernel.org/r/20220708140736.8737-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:47 -07:00
Gang Li
dcadcf1c30 mm, hugetlb: skip irrelevant nodes in show_free_areas()
show_free_areas() allows to filter out node specific data which is
irrelevant to the allocation request.  But hugetlb_show_meminfo() still
shows hugetlb on all nodes, which is redundant and unnecessary.

Use show_mem_node_skip() to skip irrelevant nodes.  And replace
hugetlb_show_meminfo() with hugetlb_show_meminfo_node(nid).

before-and-after sample output of OOM:

before:
```
[  214.362453] Node 1 active_anon:148kB inactive_anon:4050920kB active_file:112kB inactive_file:100kB
[  214.375429] Node 1 Normal free:45100kB boost:0kB min:45576kB low:56968kB high:68360kB reserved_hig
[  214.388334] lowmem_reserve[]: 0 0 0 0 0
[  214.390251] Node 1 Normal: 423*4kB (UE) 320*8kB (UME) 187*16kB (UE) 117*32kB (UE) 57*64kB (UME) 20
[  214.397626] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[  214.401518] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
```

after:
```
[  145.069705] Node 1 active_anon:128kB inactive_anon:4049412kB active_file:56kB inactive_file:84kB u
[  145.110319] Node 1 Normal free:45424kB boost:0kB min:45576kB low:56968kB high:68360kB reserved_hig
[  145.152315] lowmem_reserve[]: 0 0 0 0 0
[  145.155244] Node 1 Normal: 470*4kB (UME) 373*8kB (UME) 247*16kB (UME) 168*32kB (UE) 86*64kB (UME)
[  145.164119] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
```

Link: https://lkml.kernel.org/r/20220706034655.1834-1-ligang.bdlg@bytedance.com
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:47 -07:00
Mel Gorman
01b44456a7 mm/page_alloc: replace local_lock with normal spinlock
struct per_cpu_pages is no longer strictly local as PCP lists can be
drained remotely using a lock for protection.  While the use of local_lock
works, it goes against the intent of local_lock which is for "pure CPU
local concurrency control mechanisms and not suited for inter-CPU
concurrency control" (Documentation/locking/locktypes.rst)

local_lock protects against migration between when the percpu pointer is
accessed and the pcp->lock acquired.  The lock acquisition is a preemption
point so in the worst case, a task could migrate to another NUMA node and
accidentally allocate remote memory.  The main requirement is to pin the
task to a CPU that is suitable for PREEMPT_RT and !PREEMPT_RT.

Replace local_lock with helpers that pin a task to a CPU, lookup the
per-cpu structure and acquire the embedded lock.  It's similar to
local_lock without breaking the intent behind the API.  It is not a
complete API as only the parts needed for PCP-alloc are implemented but in
theory, the generic helpers could be promoted to a general API if there
was demand for an embedded lock within a per-cpu struct with a guarantee
that the per-cpu structure locked matches the running CPU and cannot use
get_cpu_var due to RT concerns.  PCP requires these semantics to avoid
accidentally allocating remote memory.

[mgorman@techsingularity.net: use pcp_spin_trylock_irqsave instead of pcpu_spin_trylock_irqsave]
  Link: https://lkml.kernel.org/r/20220627084645.GA27531@techsingularity.net
Link: https://lkml.kernel.org/r/20220624125423.6126-8-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:35 -07:00
Nicolas Saenz Julienne
443c2accd1 mm/page_alloc: remotely drain per-cpu lists
Some setups, notably NOHZ_FULL CPUs, are too busy to handle the per-cpu
drain work queued by __drain_all_pages().  So introduce a new mechanism to
remotely drain the per-cpu lists.  It is made possible by remotely locking
'struct per_cpu_pages' new per-cpu spinlocks.  A benefit of this new
scheme is that drain operations are now migration safe.

There was no observed performance degradation vs.  the previous scheme. 
Both netperf and hackbench were run in parallel to triggering the
__drain_all_pages(NULL, true) code path around ~100 times per second.  The
new scheme performs a bit better (~5%), although the important point here
is there are no performance regressions vs.  the previous mechanism. 
Per-cpu lists draining happens only in slow paths.

Minchan Kim tested an earlier version and reported;

	My workload is not NOHZ CPUs but run apps under heavy memory
	pressure so they goes to direct reclaim and be stuck on
	drain_all_pages until work on workqueue run.

	unit: nanosecond
	max(dur)        avg(dur)                count(dur)
	166713013       487511.77786438033      1283

	From traces, system encountered the drain_all_pages 1283 times and
	worst case was 166ms and avg was 487us.

	The other problem was alloc_contig_range in CMA. The PCP draining
	takes several hundred millisecond sometimes though there is no
	memory pressure or a few of pages to be migrated out but CPU were
	fully booked.

	Your patch perfectly removed those wasted time.

Link: https://lkml.kernel.org/r/20220624125423.6126-7-mgorman@techsingularity.net
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:35 -07:00
Mel Gorman
4b23a68f95 mm/page_alloc: protect PCP lists with a spinlock
Currently the PCP lists are protected by using local_lock_irqsave to
prevent migration and IRQ reentrancy but this is inconvenient.  Remote
draining of the lists is impossible and a workqueue is required and every
task allocation/free must disable then enable interrupts which is
expensive.

As preparation for dealing with both of those problems, protect the
lists with a spinlock.  The IRQ-unsafe version of the lock is used
because IRQs are already disabled by local_lock_irqsave.  spin_trylock
is used in combination with local_lock_irqsave() but later will be
replaced with a spin_trylock_irqsave when the local_lock is removed.

The per_cpu_pages still fits within the same number of cache lines after
this patch relative to before the series.

struct per_cpu_pages {
        spinlock_t                 lock;                 /*     0     4 */
        int                        count;                /*     4     4 */
        int                        high;                 /*     8     4 */
        int                        batch;                /*    12     4 */
        short int                  free_factor;          /*    16     2 */
        short int                  expire;               /*    18     2 */

        /* XXX 4 bytes hole, try to pack */

        struct list_head           lists[13];            /*    24   208 */

        /* size: 256, cachelines: 4, members: 7 */
        /* sum members: 228, holes: 1, sum holes: 4 */
        /* padding: 24 */
} __attribute__((__aligned__(64)));

There is overhead in the fast path due to acquiring the spinlock even
though the spinlock is per-cpu and uncontended in the common case.  Page
Fault Test (PFT) running on a 1-socket reported the following results on a
1 socket machine.

                                     5.19.0-rc3               5.19.0-rc3
                                        vanilla      mm-pcpspinirq-v5r16
Hmean     faults/sec-1   869275.7381 (   0.00%)   874597.5167 *   0.61%*
Hmean     faults/sec-3  2370266.6681 (   0.00%)  2379802.0362 *   0.40%*
Hmean     faults/sec-5  2701099.7019 (   0.00%)  2664889.7003 *  -1.34%*
Hmean     faults/sec-7  3517170.9157 (   0.00%)  3491122.8242 *  -0.74%*
Hmean     faults/sec-8  3965729.6187 (   0.00%)  3939727.0243 *  -0.66%*

There is a small hit in the number of faults per second but given that the
results are more stable, it's borderline noise.

[akpm@linux-foundation.org: add missing local_unlock_irqrestore() on contention path]
Link: https://lkml.kernel.org/r/20220624125423.6126-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:35 -07:00
Mel Gorman
e2a66c21b7 mm/page_alloc: remove mistaken page == NULL check in rmqueue
If a page allocation fails, the ZONE_BOOSTER_WATERMARK should be tested,
cleared and kswapd woken whether the allocation attempt was via the PCP or
directly via the buddy list.

Remove the page == NULL so the ZONE_BOOSTED_WATERMARK bit is checked
unconditionally.  As it is unlikely that ZONE_BOOSTED_WATERMARK is set,
mark the branch accordingly.

Link: https://lkml.kernel.org/r/20220624125423.6126-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:35 -07:00