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1040725 commits

Author SHA1 Message Date
Linus Torvalds
f1583cb1be linux-kselftest-next-5.15-rc1
This Kselftest update for Linux 5.15-rc1 consists of fixes to build
 and test failures.
 
 -- openat2 test failure for O_LARGEFILE flag on ARM64
 -- x86 test build failures related to glibc 2.34 adding
    support for variable sized MINSIGSTKSZ and SIGSTKSZ
 -- removing obsolete configs in sync and cpufreq config files
 -- minor spelling and duplicate header include cleanups
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Merge tag 'linux-kselftest-next-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest updates from Shuah Khan:
 "Fixes to build and test failures:

   - openat2 test failure for O_LARGEFILE flag on ARM64

   - x86 test build failures related to glibc 2.34 adding support for
     variable sized MINSIGSTKSZ and SIGSTKSZ

   - removing obsolete configs in sync and cpufreq config files

   - minor spelling and duplicate header include cleanups"

* tag 'linux-kselftest-next-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/cpufreq: Rename DEBUG_PI_LIST to DEBUG_PLIST
  selftests/sync: Remove the deprecated config SYNC
  selftests: safesetid: Fix spelling mistake "cant" -> "can't"
  selftests/x86: Fix error: variably modified 'altstack_data' at file scope
  kselftest:sched: remove duplicate include in cs_prctl_test.c
  selftests: openat2: Fix testing failure for O_LARGEFILE flag
2021-09-03 15:55:41 -07:00
Linus Torvalds
b250e6d141 Kbuild updates for v5.15
- Add -s option (strict mode) to merge_config.sh to make it fail when
    any symbol is redefined.
 
  - Show a warning if a different compiler is used for building external
    modules.
 
  - Infer --target from ARCH for CC=clang to let you cross-compile the
    kernel without CROSS_COMPILE.
 
  - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
 
  - Add <linux/stdarg.h> to the kernel source instead of borrowing
    <stdarg.h> from the compiler.
 
  - Add Nick Desaulniers as a Kbuild reviewer.
 
  - Drop stale cc-option tests.
 
  - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
    to handle symbols in inline assembly.
 
  - Show a warning if 'FORCE' is missing for if_changed rules.
 
  - Various cleanups
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Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add <linux/stdarg.h> to the kernel source instead of borrowing
   <stdarg.h> from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
2021-09-03 15:33:47 -07:00
Linus Torvalds
4e71add028 Merge branch 'stable/for-linus-5.15-rc0' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/ibft
Pull ibft fix from Konrad Rzeszutek Wilk:
 "An arm64 compile fix for the new code that fixed the iBFT KASLR
  handling. I missed the original 0-day build email report"

* 'stable/for-linus-5.15-rc0' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/ibft:
  iscsi_ibft: Fix isa_bus_to_virt not working under ARM
2021-09-03 15:21:54 -07:00
Linus Torvalds
7cca308cfd powerpc updates for 5.15
- Convert pseries & powernv to use MSI IRQ domains.
 
  - Rework the pseries CPU numbering so that CPUs that are removed, and later re-added, are
    given a CPU number on the same node as previously, when possible.
 
  - Add support for a new more flexible device-tree format for specifying NUMA distances.
 
  - Convert powerpc to GENERIC_PTDUMP.
 
  - Retire sbc8548 and sbc8641d board support.
 
  - Various other small features and fixes.
 
 Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Anton Blanchard, Cédric Le Goater,
 Christophe Leroy, Emmanuel Gil Peyrot, Fabiano Rosas, Fangrui Song, Finn Thain, Gautham R.
 Shenoy, Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Laurent Dufour, Leonardo
 Bras, Lukas Bulwahn, Marc Zyngier, Masahiro Yamada, Michal Suchanek, Nathan Chancellor,
 Nicholas Piggin, Parth Shah, Paul Gortmaker, Pratik R. Sampat, Randy Dunlap, Sebastian
 Andrzej Siewior, Srikar Dronamraju, Wan Jiabing, Xiongwei Song, Zheng Yongjun.
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Merge tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Convert pseries & powernv to use MSI IRQ domains.

 - Rework the pseries CPU numbering so that CPUs that are removed, and
   later re-added, are given a CPU number on the same node as
   previously, when possible.

 - Add support for a new more flexible device-tree format for specifying
   NUMA distances.

 - Convert powerpc to GENERIC_PTDUMP.

 - Retire sbc8548 and sbc8641d board support.

 - Various other small features and fixes.

Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Anton Blanchard,
Cédric Le Goater, Christophe Leroy, Emmanuel Gil Peyrot, Fabiano Rosas,
Fangrui Song, Finn Thain, Gautham R.  Shenoy, Hari Bathini, Joel
Stanley, Jordan Niethe, Kajol Jain, Laurent Dufour, Leonardo Bras, Lukas
Bulwahn, Marc Zyngier, Masahiro Yamada, Michal Suchanek, Nathan
Chancellor, Nicholas Piggin, Parth Shah, Paul Gortmaker, Pratik R.
Sampat, Randy Dunlap, Sebastian Andrzej Siewior, Srikar Dronamraju, Wan
Jiabing, Xiongwei Song, and Zheng Yongjun.

* tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (154 commits)
  powerpc/bug: Cast to unsigned long before passing to inline asm
  powerpc/ptdump: Fix generic ptdump for 64-bit
  KVM: PPC: Fix clearing never mapped TCEs in realmode
  powerpc/pseries/iommu: Rename "direct window" to "dma window"
  powerpc/pseries/iommu: Make use of DDW for indirect mapping
  powerpc/pseries/iommu: Find existing DDW with given property name
  powerpc/pseries/iommu: Update remove_dma_window() to accept property name
  powerpc/pseries/iommu: Reorganize iommu_table_setparms*() with new helper
  powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()
  powerpc/pseries/iommu: Allow DDW windows starting at 0x00
  powerpc/pseries/iommu: Add ddw_list_new_entry() helper
  powerpc/pseries/iommu: Add iommu_pseries_alloc_table() helper
  powerpc/kernel/iommu: Add new iommu_table_in_use() helper
  powerpc/pseries/iommu: Replace hard-coded page shift
  powerpc/numa: Update cpu_cpu_map on CPU online/offline
  powerpc/numa: Print debug statements only when required
  powerpc/numa: convert printk to pr_xxx
  powerpc/numa: Drop dbg in favour of pr_debug
  powerpc/smp: Enable CACHE domain for shared processor
  powerpc/smp: Update cpu_core_map on all PowerPc systems
  ...
2021-09-03 11:22:50 -07:00
Linus Torvalds
11d5576880 parisc architecture fixes for kernel 5.15-rc1:
Fix an unaligned-access crash in the bootloader and drop asm/swab.h.
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Merge tag 'for-5.15/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc architecture fixes from Helge Deller:
 "Fix an unaligned-access crash in the bootloader and drop asm/swab.h"

* tag 'for-5.15/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix unaligned-access crash in bootloader
  parisc: Drop __arch_swab16(), arch_swab24(), _arch_swab32() and __arch_swab64() functions
2021-09-03 11:15:49 -07:00
Linus Torvalds
d6742212c0 - converted Pistachio platform to use MIPS generic kernel
- fixes and cleanups
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Merge tag 'mips_5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS updates from Thomas Bogendoerfer:

 - converted Pistachio platform to use MIPS generic kernel

 - fixes and cleanups

* tag 'mips_5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (29 commits)
  MIPS: Malta: fix alignment of the devicetree buffer
  MIPS: ingenic: Unconditionally enable clock of CPU #0
  MIPS: mscc: ocelot: mark the phy-mode for internal PHY ports
  MIPS: mscc: ocelot: disable all switch ports by default
  MAINTAINERS: adjust PISTACHIO SOC SUPPORT after its retirement
  MIPS: Return true/false (not 1/0) from bool functions
  MIPS: generic: Return true/false (not 1/0) from bool functions
  MIPS: Make a alias for pistachio_defconfig
  MIPS: Retire MACH_PISTACHIO
  MIPS: config: generic: Add config for Marduk board
  pinctrl: pistachio: Make it as an option
  phy: pistachio-usb: Depend on MIPS || COMPILE_TEST
  clocksource/drivers/pistachio: Make it selectable for MIPS
  clk: pistachio: Make it selectable for generic MIPS kernel
  MIPS: DTS: Pistachio add missing cpc and cdmm
  MIPS: generic: Allow generating FIT image for Marduk board
  MIPS: locking/atomic: Fix atomic{_64,}_sub_if_positive
  MIPS: loongson2ef: don't build serial.o unconditionally
  MIPS: Replace deprecated CPU-hotplug functions.
  MIPS: Alchemy: Fix spelling contraction "cant" -> "can't"
  ...
2021-09-03 11:11:54 -07:00
Linus Torvalds
603eefda5f OpenRISC updates for 5.15
A few cleanups and compiler warning fixes for OpenRISC.  Also, this
 includes dts and defconfig updates to enable Ethernet on OpenRISC/Litex
 FPGA SoC's now that the LiteEth driver has gone upstream.
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Merge tag 'for-linus' of git://github.com/openrisc/linux

Pull OpenRISC updates from Stafford Horne:
 "A few cleanups and compiler warning fixes for OpenRISC.

  Also, this includes dts and defconfig updates to enable Ethernet on
  OpenRISC/Litex FPGA SoC's now that the LiteEth driver has gone
  upstream"

* tag 'for-linus' of git://github.com/openrisc/linux:
  openrisc/litex: Update defconfig
  openrisc/litex: Add ethernet device
  openrisc/litex: Update uart address
  openrisc: Fix compiler warnings in setup
  openrisc: rename or32 code & comments to or1k
  openrisc: don't printk() unconditionally
2021-09-03 11:03:00 -07:00
Linus Torvalds
50ddcdb263 Livepatching changes for 5.15
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Merge tag 'livepatching-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching update from Petr Mladek.

* tag 'livepatching-for-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  livepatch: Replace deprecated CPU-hotplug functions.
2021-09-03 10:57:25 -07:00
Linus Torvalds
69a5c49a91 IOMMU Updates for Linux v5.15
Including:
 
 	- New DART IOMMU driver for Apple Silicon M1 chips.
 
 	- Optimizations for iommu_[map/unmap] performance
 
 	- Selective TLB flush support for the AMD IOMMU driver to make
 	  it more efficient on emulated IOMMUs.
 
 	- Rework IOVA setup and default domain type setting to move more
 	  code out of IOMMU drivers and to support runtime switching
 	  between certain types of default domains.
 
 	- VT-d Updates from Lu Baolu:
 	  - Update the virtual command related registers
 	  - Enable Intel IOMMU scalable mode by default
 	  - Preset A/D bits for user space DMA usage
 	  - Allow devices to have more than 32 outstanding PRs
 	  - Various cleanups
 
 	- ARM SMMU Updates from Will Deacon:
 	  - SMMUv3: Minor optimisation to avoid zeroing struct members on CMD submission
 	  - SMMUv3: Increased use of batched commands to reduce submission latency
 	  - SMMUv3: Refactoring in preparation for ECMDQ support
 	  - SMMUv2: Fix races when probing devices with identical StreamIDs
 	  - SMMUv2: Optimise walk cache flushing for Qualcomm implementations
 	  - SMMUv2: Allow deep sleep states for some Qualcomm SoCs with shared clocks
 
 	- Various smaller optimizations, cleanups, and fixes
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Merge tag 'iommu-updates-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu updates from Joerg Roedel:

 - New DART IOMMU driver for Apple Silicon M1 chips

 - Optimizations for iommu_[map/unmap] performance

 - Selective TLB flush support for the AMD IOMMU driver to make it more
   efficient on emulated IOMMUs

 - Rework IOVA setup and default domain type setting to move more code
   out of IOMMU drivers and to support runtime switching between certain
   types of default domains

 - VT-d Updates from Lu Baolu:
      - Update the virtual command related registers
      - Enable Intel IOMMU scalable mode by default
      - Preset A/D bits for user space DMA usage
      - Allow devices to have more than 32 outstanding PRs
      - Various cleanups

 - ARM SMMU Updates from Will Deacon:
      SMMUv3:
       - Minor optimisation to avoid zeroing struct members on CMD submission
       - Increased use of batched commands to reduce submission latency
       - Refactoring in preparation for ECMDQ support
      SMMUv2:
       - Fix races when probing devices with identical StreamIDs
       - Optimise walk cache flushing for Qualcomm implementations
       - Allow deep sleep states for some Qualcomm SoCs with shared clocks

 - Various smaller optimizations, cleanups, and fixes

* tag 'iommu-updates-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (85 commits)
  iommu/io-pgtable: Abstract iommu_iotlb_gather access
  iommu/arm-smmu: Fix missing unlock on error in arm_smmu_device_group()
  iommu/vt-d: Add present bit check in pasid entry setup helpers
  iommu/vt-d: Use pasid_pte_is_present() helper function
  iommu/vt-d: Drop the kernel doc annotation
  iommu/vt-d: Allow devices to have more than 32 outstanding PRs
  iommu/vt-d: Preset A/D bits for user space DMA usage
  iommu/vt-d: Enable Intel IOMMU scalable mode by default
  iommu/vt-d: Refactor Kconfig a bit
  iommu/vt-d: Remove unnecessary oom message
  iommu/vt-d: Update the virtual command related registers
  iommu: Allow enabling non-strict mode dynamically
  iommu: Merge strictness and domain type configs
  iommu: Only log strictness for DMA domains
  iommu: Expose DMA domain strictness via sysfs
  iommu: Express DMA strictness via the domain type
  iommu/vt-d: Prepare for multiple DMA domain types
  iommu/arm-smmu: Prepare for multiple DMA domain types
  iommu/amd: Prepare for multiple DMA domain types
  iommu: Introduce explicit type for non-strict DMA domains
  ...
2021-09-03 10:44:35 -07:00
Linus Torvalds
3de18c865f Merge branch 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "A new feature called restricted DMA pools. It allows SWIOTLB to
  utilize per-device (or per-platform) allocated memory pools instead of
  using the global one.

  The first big user of this is ARM Confidential Computing where the
  memory for DMA operations can be set per platform"

* 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: (23 commits)
  swiotlb: use depends on for DMA_RESTRICTED_POOL
  of: restricted dma: Don't fail device probe on rmem init failure
  of: Move of_dma_set_restricted_buffer() into device.c
  powerpc/svm: Don't issue ultracalls if !mem_encrypt_active()
  s390/pv: fix the forcing of the swiotlb
  swiotlb: Free tbl memory in swiotlb_exit()
  swiotlb: Emit diagnostic in swiotlb_exit()
  swiotlb: Convert io_default_tlb_mem to static allocation
  of: Return success from of_dma_set_restricted_buffer() when !OF_ADDRESS
  swiotlb: add overflow checks to swiotlb_bounce
  swiotlb: fix implicit debugfs declarations
  of: Add plumbing for restricted DMA pool
  dt-bindings: of: Add restricted DMA pool
  swiotlb: Add restricted DMA pool initialization
  swiotlb: Add restricted DMA alloc/free support
  swiotlb: Refactor swiotlb_tbl_unmap_single
  swiotlb: Move alloc_size to swiotlb_find_slots
  swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing
  swiotlb: Update is_swiotlb_active to add a struct device argument
  swiotlb: Update is_swiotlb_buffer to add a struct device argument
  ...
2021-09-03 10:34:44 -07:00
Linus Torvalds
14726903c8 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "173 patches.

  Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
  pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
  bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
  hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
  oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
  mm/madvise: add MADV_WILLNEED to process_madvise()
  mm/vmstat: remove unneeded return value
  mm/vmstat: simplify the array size calculation
  mm/vmstat: correct some wrong comments
  mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
  selftests: vm: add COW time test for KSM pages
  selftests: vm: add KSM merging time test
  mm: KSM: fix data type
  selftests: vm: add KSM merging across nodes test
  selftests: vm: add KSM zero page merging test
  selftests: vm: add KSM unmerge test
  selftests: vm: add KSM merge test
  mm/migrate: correct kernel-doc notation
  mm: wire up syscall process_mrelease
  mm: introduce process_mrelease system call
  memblock: make memblock_find_in_range method private
  mm/mempolicy.c: use in_task() in mempolicy_slab_node()
  mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
  mm/mempolicy: advertise new MPOL_PREFERRED_MANY
  mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
  ...
2021-09-03 10:08:28 -07:00
zhangkui
d5fffc5aff mm/madvise: add MADV_WILLNEED to process_madvise()
There is a usecase in Android that an app process's memory is swapped out
by process_madvise() with MADV_PAGEOUT, such as the memory is swapped to
zram or a backing device.  When the process is scheduled to running, like
switch to foreground, multiple page faults may cause the app dropped
frames.

To reduce the problem, System Management Software can read-ahead memory
of the process immediately when the app switches to forground.  Calling
process_madvise() with MADV_WILLNEED can meet this need.

Link: https://lkml.kernel.org/r/20210804082010.12482-1-zhangkui@oppo.com
Signed-off-by: zhangkui <zhangkui@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Miaohe Lin
33090af973 mm/vmstat: remove unneeded return value
The return value of pagetypeinfo_showfree and pagetypeinfo_showblockcount
are unused now.  Remove them.

Link: https://lkml.kernel.org/r/20210715122911.15700-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Miaohe Lin
64632fd3eb mm/vmstat: simplify the array size calculation
We can replace the array_num * sizeof(array[0]) with sizeof(array) to
simplify the code.

Link: https://lkml.kernel.org/r/20210715122911.15700-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Miaohe Lin
ea15ba17b4 mm/vmstat: correct some wrong comments
Patch series "Cleanup for vmstat".

This series contains cleanups to remove unneeded return value, correct
wrong comment and simplify the array size calculation.  More details can
be found in the respective changelogs.

This patch (of 3):

Correct wrong fls(mem+1) to fls(mem)+1 and remove the duplicated comment
with quiet_vmstat().

Link: https://lkml.kernel.org/r/20210715122911.15700-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210715122911.15700-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Jing Xiangfeng
3198145049 mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
Commit b239f7daf5 ("percpu: set PCPU_BITMAP_BLOCK_SIZE to PAGE_SIZE")
removed the parameter 'for_alloc', so remove this comment.

Link: https://lkml.kernel.org/r/1630576043-21367-1-git-send-email-jingxiangfeng@huawei.com
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
924a11bd16 selftests: vm: add COW time test for KSM pages
Since merged pages are copied every time they need to be modified, the
write access time is different between shared and non-shared pages.  Add
ksm_cow_time() function which evaluates latency of these COW breaks.
First, 4000 pages are allocated and the time, required to modify 1 byte in
every other page, is measured.  After this, the pages are merged into 2000
pairs and in each pair, 1 page is modified (i.e.  they are decoupled) to
detect COW breaks.  The time needed to break COW of merged pages is then
compared with performance of non-shared pages.

The test is run as follows: ./ksm_tests -C
The output:
	Total size:    15 MiB

	Not merged pages:
	Total time:     0.002185489 s
	Average speed:  3202.945 MiB/s

	Merged pages:
	Total time:     0.004386872 s
	Average speed:  1595.670 MiB/s

Link: https://lkml.kernel.org/r/1d03ee0d1b341959d4b61672c6401d498bff5652.1629386192.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
9e7cb94ca2 selftests: vm: add KSM merging time test
Patch series "add KSM performance tests", v3.

Extend KSM self tests with a performance benchmark.  These tests are not
part of regular regression testing, as they are mainly intended to be used
by developers making changes to the memory management subsystem.

This patch (of 2):

Add ksm_merge_time() function to determine speed and time needed for
merging.  The total spent time is shown in seconds while speed is in
MiB/s.  User must specify the size of duplicated memory area (in MiB)
before running the test.

The test is run as follows: ./ksm_tests -P -s 100
The output:
	Total size:    100 MiB
	Total time:    0.201106786 s
	Average speed:  497.248 MiB/s

Link: https://lkml.kernel.org/r/cover.1629386192.git.zhansayabagdaulet@gmail.com
Link: https://lkml.kernel.org/r/318b946ac80cc9205c89d0962048378f7ce0705b.1629386192.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
584ff0dfb0 mm: KSM: fix data type
ksm_stable_node_chains_prune_millisecs is declared as int, but in
stable__node_chains_prune_millisecs_store(), it can store values up to
UINT_MAX.  Change its type to unsigned int.

Link: https://lkml.kernel.org/r/20210806111351.GA71845@asus
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
82e717ad35 selftests: vm: add KSM merging across nodes test
Add check_ksm_numa_merge() function to test that pages in different NUMA
nodes are being handled properly.  First, two duplicate pages are
allocated in two separate NUMA nodes using the libnuma library.  Since
there is one unique page in each node, with merge_across_nodes = 0, there
won't be any shared pages.  If merge_across_nodes is set to 1, the pages
will be treated as usual duplicate pages and will be merged.  If NUMA
config is not enabled or the number of NUMA nodes is less than two, then
the test is skipped.  The test is run as follows: ./ksm_tests -N

Link: https://lkml.kernel.org/r/071c17b5b04ebb0dfeba137acc495e5dd9d2a719.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
39619982c5 selftests: vm: add KSM zero page merging test
Add check_ksm_zero_page_merge() function to test that empty pages are
being handled properly.  For this, several zero pages are allocated and
merged using madvise.  If use_zero_pages is enabled, the pages must be
shared with the special kernel zero pages; otherwise, they are merged as
usual duplicate pages.  The test is run as follows: ./ksm_tests -Z

Link: https://lkml.kernel.org/r/6d0caab00d4bdccf5e3791cb95cf6dfd5eb85e45.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
a40c80e348 selftests: vm: add KSM unmerge test
Add check_ksm_unmerge() function to verify that KSM is properly unmerging
shared pages.  For this, two duplicate pages are merged first and then
their contents are modified.  Since they are not identical anymore, the
pages must be unmerged and the number of merged pages has to be 0.  The
test is run as follows: ./ksm_tests -U

Link: https://lkml.kernel.org/r/c0f55420440d704d5b094275b4365aa1b2ad46b5.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Zhansaya Bagdauletkyzy
68d6289baa selftests: vm: add KSM merge test
Patch series "add KSM selftests".

Introduce selftests to validate the functionality of KSM.  The tests are
run on private anonymous pages.  Since some KSM tunables are modified,
their starting values are saved and restored after testing.  At the start,
run is set to 2 to ensure that only test pages will be merged (we assume
that no applications make madvise syscalls in the background).  If KSM
config not enabled, all tests will be skipped.

This patch (of 4):

Add check_ksm_merge() function to check the basic merging feature of KSM.
First, some number of identical pages are allocated and the MADV_MERGEABLE
advice is given to merge these pages.  Then, pages_shared and
pages_sharing values are compared with the expected numbers using
assert_ksm_pages_count() function.  The number of pages can be changed
using -p option.

Link: https://lkml.kernel.org/r/cover.1626252248.git.zhansayabagdaulet@gmail.com
Link: https://lkml.kernel.org/r/90287685c13300972ea84de93d1f3f900373f9fe.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Randy Dunlap
c9bd7d1836 mm/migrate: correct kernel-doc notation
Use the expected "Return:" format to prevent a kernel-doc warning.

mm/migrate.c:1157: warning: Excess function parameter 'returns' description in 'next_demotion_node'

Link: https://lkml.kernel.org/r/20210808203151.10632-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:18 -07:00
Suren Baghdasaryan
dce4910396 mm: wire up syscall process_mrelease
Split off from prev patch in the series that implements the syscall.

Link: https://lkml.kernel.org/r/20210809185259.405936-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Suren Baghdasaryan
884a7e5964 mm: introduce process_mrelease system call
In modern systems it's not unusual to have a system component monitoring
memory conditions of the system and tasked with keeping system memory
pressure under control.  One way to accomplish that is to kill
non-essential processes to free up memory for more important ones.
Examples of this are Facebook's OOM killer daemon called oomd and
Android's low memory killer daemon called lmkd.

For such system component it's important to be able to free memory quickly
and efficiently.  Unfortunately the time process takes to free up its
memory after receiving a SIGKILL might vary based on the state of the
process (uninterruptible sleep), size and OPP level of the core the
process is running.  A mechanism to free resources of the target process
in a more predictable way would improve system's ability to control its
memory pressure.

Introduce process_mrelease system call that releases memory of a dying
process from the context of the caller.  This way the memory is freed in a
more controllable way with CPU affinity and priority of the caller.  The
workload of freeing the memory will also be charged to the caller.  The
operation is allowed only on a dying process.

After previous discussions [1, 2, 3] the decision was made [4] to
introduce a dedicated system call to cover this use case.

The API is as follows,

          int process_mrelease(int pidfd, unsigned int flags);

        DESCRIPTION
          The process_mrelease() system call is used to free the memory of
          an exiting process.

          The pidfd selects the process referred to by the PID file
          descriptor.
          (See pidfd_open(2) for further information)

          The flags argument is reserved for future use; currently, this
          argument must be specified as 0.

        RETURN VALUE
          On success, process_mrelease() returns 0. On error, -1 is
          returned and errno is set to indicate the error.

        ERRORS
          EBADF  pidfd is not a valid PID file descriptor.

          EAGAIN Failed to release part of the address space.

          EINTR  The call was interrupted by a signal; see signal(7).

          EINVAL flags is not 0.

          EINVAL The memory of the task cannot be released because the
                 process is not exiting, the address space is shared
                 with another live process or there is a core dump in
                 progress.

          ENOSYS This system call is not supported, for example, without
                 MMU support built into Linux.

          ESRCH  The target process does not exist (i.e., it has terminated
                 and been waited on).

[1] https://lore.kernel.org/lkml/20190411014353.113252-3-surenb@google.com/
[2] https://lore.kernel.org/linux-api/20201113173448.1863419-1-surenb@google.com/
[3] https://lore.kernel.org/linux-api/20201124053943.1684874-3-surenb@google.com/
[4] https://lore.kernel.org/linux-api/20201223075712.GA4719@lst.de/

Link: https://lkml.kernel.org/r/20210809185259.405936-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Mike Rapoport
a7259df767 memblock: make memblock_find_in_range method private
There are a lot of uses of memblock_find_in_range() along with
memblock_reserve() from the times memblock allocation APIs did not exist.

memblock_find_in_range() is the very core of memblock allocations, so any
future changes to its internal behaviour would mandate updates of all the
users outside memblock.

Replace the calls to memblock_find_in_range() with an equivalent calls to
memblock_phys_alloc() and memblock_phys_alloc_range() and make
memblock_find_in_range() private method of memblock.

This simplifies the callers, ensures that (unlikely) errors in
memblock_reserve() are handled and improves maintainability of
memblock_find_in_range().

Link: https://lkml.kernel.org/r/20210816122622.30279-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>		[arm64]
Acked-by: Kirill A. Shutemov <kirill.shtuemov@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>	[ACPI]
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Nick Kossifidis <mick@ics.forth.gr>			[riscv]
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Vasily Averin
38b031dd4d mm/mempolicy.c: use in_task() in mempolicy_slab_node()
Obsoleted in_intrrupt() include task context with disabled BH, it's better
to use in_task() instead.

Link: https://lkml.kernel.org/r/984ee771-4834-21da-801f-c15c18ddf4d1@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Feng Tang
be897d48a9 mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
As they all do the same thing: sanity check and save nodemask info, create
one mpol_new_nodemask() to reduce redundancy.

Link: https://lkml.kernel.org/r/1627970362-61305-6-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Ben Widawsky
a38a59fdfa mm/mempolicy: advertise new MPOL_PREFERRED_MANY
Adds a new mode to the existing mempolicy modes, MPOL_PREFERRED_MANY.

MPOL_PREFERRED_MANY will be adequately documented in the internal
admin-guide with this patch.  Eventually, the man pages for mbind(2),
get_mempolicy(2), set_mempolicy(2) and numactl(8) will also have text
about this mode.  Those shall contain the canonical reference.

NUMA systems continue to become more prevalent.  New technologies like
PMEM make finer grain control over memory access patterns increasingly
desirable.  MPOL_PREFERRED_MANY allows userspace to specify a set of nodes
that will be tried first when performing allocations.  If those
allocations fail, all remaining nodes will be tried.  It's a straight
forward API which solves many of the presumptive needs of system
administrators wanting to optimize workloads on such machines.  The mode
will work either per VMA, or per thread.

[Michal Hocko: refine kernel doc for MPOL_PREFERRED_MANY]

Link: https://lore.kernel.org/r/20200630212517.308045-13-ben.widawsky@intel.com
Link: https://lkml.kernel.org/r/1627970362-61305-5-git-send-email-feng.tang@intel.com
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Ben Widawsky
cfcaa66f80 mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
Implement the missing huge page allocation functionality while obeying the
preferred node semantics.  This is similar to the implementation for
general page allocation, as it uses a fallback mechanism to try multiple
preferred nodes first, and then all other nodes.

To avoid adding too many "#ifdef CONFIG_NUMA" check, add a helper function
in mempolicy.h to check whether a mempolicy is MPOL_PREFERRED_MANY.

[akpm@linux-foundation.org: fix compiling issue when merging with other hugetlb patch]
[Thanks to 0day bot for catching the !CONFIG_NUMA compiling issue]
[mhocko@suse.com: suggest to remove the #ifdef CONFIG_NUMA check]
[ben.widawsky@intel.com: add helpers to avoid ifdefs]
  Link: https://lore.kernel.org/r/20200630212517.308045-12-ben.widawsky@intel.com
  Link: https://lkml.kernel.org/r/1627970362-61305-4-git-send-email-feng.tang@intel.com
  Link: https://lkml.kernel.org/r/20210809024430.GA46432@shbuild999.sh.intel.com
[nathan@kernel.org: initialize page to NULL in alloc_buddy_huge_page_with_mpol()]
  Link: https://lkml.kernel.org/r/20210810200632.3812797-1-nathan@kernel.org

Link: https://lore.kernel.org/r/20200630212517.308045-12-ben.widawsky@intel.com
Link: https://lkml.kernel.org/r/1627970362-61305-4-git-send-email-feng.tang@intel.com
Link: https://lkml.kernel.org/r/20210809024430.GA46432@shbuild999.sh.intel.com
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Co-developed-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Feng Tang
4c54d94908 mm/memplicy: add page allocation function for MPOL_PREFERRED_MANY policy
The semantics of MPOL_PREFERRED_MANY is similar to MPOL_PREFERRED, that it
will first try to allocate memory from the preferred node(s), and fallback
to all nodes in system when first try fails.

Add a dedicated function alloc_pages_preferred_many() for it just like for
'interleave' policy, which will be used by 2 general memoory allocation
APIs: alloc_pages() and alloc_pages_vma()

Link: https://lore.kernel.org/r/20200630212517.308045-9-ben.widawsky@intel.com
Link: https://lkml.kernel.org/r/1627970362-61305-3-git-send-email-feng.tang@intel.com
Suggested-by: Michal Hocko <mhocko@suse.com>
Originally-by: Ben Widawsky <ben.widawsky@intel.com>
Co-developed-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Dave Hansen
b27abaccf8 mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes
Patch series "Introduce multi-preference mempolicy", v7.

This patch series introduces the concept of the MPOL_PREFERRED_MANY
mempolicy.  This mempolicy mode can be used with either the
set_mempolicy(2) or mbind(2) interfaces.  Like the MPOL_PREFERRED
interface, it allows an application to set a preference for nodes which
will fulfil memory allocation requests.  Unlike the MPOL_PREFERRED mode,
it takes a set of nodes.  Like the MPOL_BIND interface, it works over a
set of nodes.  Unlike MPOL_BIND, it will not cause a SIGSEGV or invoke the
OOM killer if those preferred nodes are not available.

Along with these patches are patches for libnuma, numactl, numademo, and
memhog.  They still need some polish, but can be found here:
https://gitlab.com/bwidawsk/numactl/-/tree/prefer-many It allows new
usage: `numactl -P 0,3,4`

The goal of the new mode is to enable some use-cases when using tiered memory
usage models which I've lovingly named.

1a. The Hare - The interconnect is fast enough to meet bandwidth and
    latency requirements allowing preference to be given to all nodes with
    "fast" memory.
1b. The Indiscriminate Hare - An application knows it wants fast
    memory (or perhaps slow memory), but doesn't care which node it runs
    on.  The application can prefer a set of nodes and then xpu bind to
    the local node (cpu, accelerator, etc).  This reverses the nodes are
    chosen today where the kernel attempts to use local memory to the CPU
    whenever possible.  This will attempt to use the local accelerator to
    the memory.
2.  The Tortoise - The administrator (or the application itself) is
    aware it only needs slow memory, and so can prefer that.

Much of this is almost achievable with the bind interface, but the bind
interface suffers from an inability to fallback to another set of nodes if
binding fails to all nodes in the nodemask.

Like MPOL_BIND a nodemask is given. Inherently this removes ordering from the
preference.

> /* Set first two nodes as preferred in an 8 node system. */
> const unsigned long nodes = 0x3
> set_mempolicy(MPOL_PREFER_MANY, &nodes, 8);

> /* Mimic interleave policy, but have fallback *.
> const unsigned long nodes = 0xaa
> set_mempolicy(MPOL_PREFER_MANY, &nodes, 8);

Some internal discussion took place around the interface. There are two
alternatives which we have discussed, plus one I stuck in:

1. Ordered list of nodes.  Currently it's believed that the added
   complexity is nod needed for expected usecases.
2. A flag for bind to allow falling back to other nodes.  This
   confuses the notion of binding and is less flexible than the current
   solution.
3. Create flags or new modes that helps with some ordering.  This
   offers both a friendlier API as well as a solution for more customized
   usage.  It's unknown if it's worth the complexity to support this.
   Here is sample code for how this might work:

> // Prefer specific nodes for some something wacky
> set_mempolicy(MPOL_PREFER_MANY, 0x17c, 1024);
>
> // Default
> set_mempolicy(MPOL_PREFER_MANY | MPOL_F_PREFER_ORDER_SOCKET, NULL, 0);
> // which is the same as
> set_mempolicy(MPOL_DEFAULT, NULL, 0);
>
> // The Hare
> set_mempolicy(MPOL_PREFER_MANY | MPOL_F_PREFER_ORDER_TYPE, NULL, 0);
>
> // The Tortoise
> set_mempolicy(MPOL_PREFER_MANY | MPOL_F_PREFER_ORDER_TYPE_REV, NULL, 0);
>
> // Prefer the fast memory of the first two sockets
> set_mempolicy(MPOL_PREFER_MANY | MPOL_F_PREFER_ORDER_TYPE, -1, 2);
>

This patch (of 5):

The NUMA APIs currently allow passing in a "preferred node" as a single
bit set in a nodemask.  If more than one bit it set, bits after the first
are ignored.

This single node is generally OK for location-based NUMA where memory
being allocated will eventually be operated on by a single CPU.  However,
in systems with multiple memory types, folks want to target a *type* of
memory instead of a location.  For instance, someone might want some
high-bandwidth memory but do not care about the CPU next to which it is
allocated.  Or, they want a cheap, high capacity allocation and want to
target all NUMA nodes which have persistent memory in volatile mode.  In
both of these cases, the application wants to target a *set* of nodes, but
does not want strict MPOL_BIND behavior as that could lead to OOM killer
or SIGSEGV.

So add MPOL_PREFERRED_MANY policy to support the multiple preferred nodes
requirement.  This is not a pie-in-the-sky dream for an API.  This was a
response to a specific ask of more than one group at Intel.  Specifically:

1. There are existing libraries that target memory types such as
   https://github.com/memkind/memkind.  These are known to suffer from
   SIGSEGV's when memory is low on targeted memory "kinds" that span more
   than one node.  The MCDRAM on a Xeon Phi in "Cluster on Die" mode is an
   example of this.

2. Volatile-use persistent memory users want to have a memory policy
   which is targeted at either "cheap and slow" (PMEM) or "expensive and
   fast" (DRAM).  However, they do not want to experience allocation
   failures when the targeted type is unavailable.

3. Allocate-then-run.  Generally, we let the process scheduler decide
   on which physical CPU to run a task.  That location provides a default
   allocation policy, and memory availability is not generally considered
   when placing tasks.  For situations where memory is valuable and
   constrained, some users want to allocate memory first, *then* allocate
   close compute resources to the allocation.  This is the reverse of the
   normal (CPU) model.  Accelerators such as GPUs that operate on
   core-mm-managed memory are interested in this model.

A check is added in sanitize_mpol_flags() to not permit 'prefer_many'
policy to be used for now, and will be removed in later patch after all
implementations for 'prefer_many' are ready, as suggested by Michal Hocko.

[mhocko@kernel.org: suggest to refine policy_node/policy_nodemask handling]

Link: https://lkml.kernel.org/r/1627970362-61305-1-git-send-email-feng.tang@intel.com
Link: https://lore.kernel.org/r/20200630212517.308045-4-ben.widawsky@intel.com
Link: https://lkml.kernel.org/r/1627970362-61305-2-git-send-email-feng.tang@intel.com
Co-developed-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>b
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Baolin Wang
062db29358 mm/mempolicy: use readable NUMA_NO_NODE macro instead of magic number
The caller of mpol_misplaced() already use NUMA_NO_NODE to check whether
current page node is misplaced, thus using NUMA_NO_NODE in
mpol_misplaced() instead of magic number is more readable.

Link: https://lkml.kernel.org/r/1b77c0ce21183fa86f4db250b115cf5e27396528.1627558356.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Charan Teja Reddy
65d759c8f9 mm: compaction: support triggering of proactive compaction by user
The proactive compaction[1] gets triggered for every 500msec and run
compaction on the node for COMPACTION_HPAGE_ORDER (usually order-9) pages
based on the value set to sysctl.compaction_proactiveness.  Triggering the
compaction for every 500msec in search of COMPACTION_HPAGE_ORDER pages is
not needed for all applications, especially on the embedded system
usecases which may have few MB's of RAM.  Enabling the proactive
compaction in its state will endup in running almost always on such
systems.

Other side, proactive compaction can still be very much useful for getting
a set of higher order pages in some controllable manner(controlled by
using the sysctl.compaction_proactiveness).  So, on systems where enabling
the proactive compaction always may proove not required, can trigger the
same from user space on write to its sysctl interface.  As an example, say
app launcher decide to launch the memory heavy application which can be
launched fast if it gets more higher order pages thus launcher can prepare
the system in advance by triggering the proactive compaction from
userspace.

This triggering of proactive compaction is done on a write to
sysctl.compaction_proactiveness by user.

[1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=facdaa917c4d5a376d09d25865f5a863f906234a

[akpm@linux-foundation.org: tweak vm.rst, per Mike]

Link: https://lkml.kernel.org/r/1627653207-12317-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Charan Teja Reddy
e1e92bfa38 mm: compaction: optimize proactive compaction deferrals
Vlastimil Babka figured out that when fragmentation score didn't go down
across the proactive compaction i.e.  when no progress is made, next wake
up for proactive compaction is deferred for 1 << COMPACT_MAX_DEFER_SHIFT,
i.e.  64 times, with each wakeup interval of
HPAGE_FRAG_CHECK_INTERVAL_MSEC(=500).  In each of this wakeup, it just
decrement 'proactive_defer' counter and goes sleep i.e.  it is getting
woken to just decrement a counter.

The same deferral time can also achieved by simply doing the
HPAGE_FRAG_CHECK_INTERVAL_MSEC << COMPACT_MAX_DEFER_SHIFT thus unnecessary
wakeup of kcompact thread is avoided thus also removes the need of
'proactive_defer' thread counter.

[akpm@linux-foundation.org: tweak comment]

Link: https://lore.kernel.org/linux-fsdevel/88abfdb6-2c13-b5a6-5b46-742d12d1c910@suse.cz/
Link: https://lkml.kernel.org/r/1626869599-25412-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Vlastimil Babka
1399af7e54 mm, vmscan: guarantee drop_slab_node() termination
drop_slab_node() is called as part of echo 2>/proc/sys/vm/drop_caches
operation.  It iterates over all memcgs and calls shrink_slab() which in
turn iterates over all slab shrinkers.  Freed objects are counted and as
long as the total number of freed objects from all memcgs and shrinkers is
higher than 10, drop_slab_node() loops for another full memcgs*shrinkers
iteration.

This arbitrary constant threshold of 10 can result in effectively an
infinite loop on a system with large number of memcgs and/or parallel
activity that allocates new objects.  This has been reported previously by
Chunxin Zang [1] and recently by our customer.

The previous report [1] has resulted in commit 069c411de4 ("mm/vmscan:
fix infinite loop in drop_slab_node") which added a check for signals
allowing the user to terminate the command writing to drop_caches.  At the
time it was also considered to make the threshold grow with each iteration
to guarantee termination, but such patch hasn't been formally proposed
yet.

This patch implements the dynamically growing threshold.  At first
iteration it's enough to free one object to continue, and this threshold
effectively doubles with each iteration.  Our customer's feedback was
positive.

There is always a risk that this change will result on some system in a
previously terminating drop_caches operation to terminate sooner and free
fewer objects.  Ideally the semantics would guarantee freeing all freeable
objects that existed at the moment of starting the operation, while not
looping forever for newly allocated objects, but that's not feasible to
track.  In the less ideal solution based on thresholds, arguably the
termination guarantee is more important than the exhaustiveness guarantee.
If there are reports of large regression wrt being exhaustive, we can
tune how fast the threshold grows.

[1] https://lore.kernel.org/lkml/20200909152047.27905-1-zangchunxin@bytedance.com/T/#u

[vbabka@suse.cz: avoid undefined shift behaviour]
  Link: https://lkml.kernel.org/r/2f034e6f-a753-550a-f374-e4e23899d3d5@suse.cz

Link: https://lkml.kernel.org/r/20210818152239.25502-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Chunxin Zang <zangchunxin@bytedance.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Miaohe Lin
2e786d9e5a mm/vmscan: add 'else' to remove check_pending label
We could add 'else' to remove the somewhat odd check_pending label to make
code core succinct.

Link: https://lkml.kernel.org/r/20210717065911.61497-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Miaohe Lin
b87c517ac5 mm/vmscan: remove unneeded return value of kswapd_run()
The return value of kswapd_run() is unused now.  Clean it up.

Link: https://lkml.kernel.org/r/20210717065911.61497-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Miaohe Lin
eaad1ae781 mm/vmscan: remove misleading setting to sc->priority
The priority field of sc is used to control how many pages we should scan
at once while we always traverse the list to shrink the pages in these
functions.  So these settings are unneeded and misleading.

Link: https://lkml.kernel.org/r/20210717065911.61497-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Miaohe Lin
d17be2d9ff mm/vmscan: remove the PageDirty check after MADV_FREE pages are page_ref_freezed
Patch series "Cleanups for vmscan", v2.

This series contains cleanups to remove unneeded return value, misleading
setting and so on.  Also this remove the PageDirty check after MADV_FREE
pages are page_ref_freezed.  More details can be found in the respective
changelogs.

This patch (of 4):

If the MADV_FREE pages are redirtied before they could be reclaimed, put
the pages back to anonymous LRU list by setting SwapBacked flag and the
pages will be reclaimed in normal swapout way.  But as Yu Zhao pointed
out, "The page has only one reference left, which is from the isolation.
After the caller puts the page back on lru and drops the reference, the
page will be freed anyway.  It doesn't matter which lru it goes." So we
don't bother checking PageDirty here.

[Yu Zhao's comment is also quoted in the code.]

Link: https://lkml.kernel.org/r/20210717065911.61497-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210717065911.61497-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Hui Su
9647875be5 mm/vmpressure: replace vmpressure_to_css() with vmpressure_to_memcg()
We can get memcg directly form vmpr instead of vmpr->memcg->css->memcg, so
add a new func helper vmpressure_to_memcg().  And no code will use
vmpressure_to_css(), so delete it.

Link: https://lkml.kernel.org/r/20210630112146.455103-1-suhui@zeku.com
Signed-off-by: Hui Su <suhui@zeku.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:17 -07:00
Huang Ying
20b51af15e mm/migrate: add sysfs interface to enable reclaim migration
Some method is obviously needed to enable reclaim-based migration.

Just like traditional autonuma, there will be some workloads that will
benefit like workloads with more "static" configurations where hot pages
stay hot and cold pages stay cold.  If pages come and go from the hot and
cold sets, the benefits of this approach will be more limited.

The benefits are truly workload-based and *not* hardware-based.  We do not
believe that there is a viable threshold where certain hardware
configurations should have this mechanism enabled while others do not.

To be conservative, earlier work defaulted to disable reclaim- based
migration and did not include a mechanism to enable it.  This proposes add
a new sysfs file

  /sys/kernel/mm/numa/demotion_enabled

as a method to enable it.

We are open to any alternative that allows end users to enable this
mechanism or disable it if workload harm is detected (just like
traditional autonuma).

Once this is enabled page demotion may move data to a NUMA node that does
not fall into the cpuset of the allocating process.  This could be
construed to violate the guarantees of cpusets.  However, since this is an
opt-in mechanism, the assumption is that anyone enabling it is content to
relax the guarantees.

Link: https://lkml.kernel.org/r/20210721063926.3024591-9-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-10-ying.huang@intel.com
Signed-off-by: Huang Ying <ying.huang@intel.com>
Originally-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Dave Hansen
3a235693d3 mm/vmscan: never demote for memcg reclaim
Global reclaim aims to reduce the amount of memory used on a given node or
set of nodes.  Migrating pages to another node serves this purpose.

memcg reclaim is different.  Its goal is to reduce the total memory
consumption of the entire memcg, across all nodes.  Migration does not
assist memcg reclaim because it just moves page contents between nodes
rather than actually reducing memory consumption.

Link: https://lkml.kernel.org/r/20210715055145.195411-9-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Keith Busch
a2a36488a6 mm/vmscan: Consider anonymous pages without swap
Reclaim anonymous pages if a migration path is available now that demotion
provides a non-swap recourse for reclaiming anon pages.

Note that this check is subtly different from the can_age_anon_pages()
checks.  This mechanism checks whether a specific page in a specific
context can actually be reclaimed, given current swap space and cgroup
limits.

can_age_anon_pages() is a much simpler and more preliminary check which
just says whether there is a possibility of future reclaim.

[kbusch@kernel.org: v11]
  Link: https://lkml.kernel.org/r/20210715055145.195411-8-ying.huang@intel.com
  Link: https://lkml.kernel.org/r/20210721063926.3024591-7-ying.huang@intel.com

Link: https://lkml.kernel.org/r/20210715055145.195411-8-ying.huang@intel.com
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Dave Hansen
2f368a9fb7 mm/vmscan: add helper for querying ability to age anonymous pages
Anonymous pages are kept on their own LRU(s).  These lists could
theoretically always be scanned and maintained.  But, without swap, there
is currently nothing the kernel can *do* with the results of a scanned,
sorted LRU for anonymous pages.

A check for '!total_swap_pages' currently serves as a valid check as to
whether anonymous LRUs should be maintained.  However, another method will
be added shortly: page demotion.

Abstract out the 'total_swap_pages' checks into a helper, give it a
logically significant name, and check for the possibility of page
demotion.

[dave.hansen@linux.intel.com: v11]
  Link: https://lkml.kernel.org/r/20210715055145.195411-7-ying.huang@intel.com
  Link: https://lkml.kernel.org/r/20210721063926.3024591-6-ying.huang@intel.com

Link: https://lkml.kernel.org/r/20210715055145.195411-7-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Yang Shi
668e4147d8 mm/vmscan: add page demotion counter
Account the number of demoted pages.

Add pgdemote_kswapd and pgdemote_direct VM counters showed in
/proc/vmstat.

[ daveh:
   - __count_vm_events() a bit, and made them look at the THP
     size directly rather than getting data from migrate_pages()
]

Link: https://lkml.kernel.org/r/20210721063926.3024591-5-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-6-ying.huang@intel.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Wei Xu <weixugc@google.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Dave Hansen
26aa2d199d mm/migrate: demote pages during reclaim
This is mostly derived from a patch from Yang Shi:

	https://lore.kernel.org/linux-mm/1560468577-101178-10-git-send-email-yang.shi@linux.alibaba.com/

Add code to the reclaim path (shrink_page_list()) to "demote" data to
another NUMA node instead of discarding the data.  This always avoids the
cost of I/O needed to read the page back in and sometimes avoids the
writeout cost when the page is dirty.

A second pass through shrink_page_list() will be made if any demotions
fail.  This essentially falls back to normal reclaim behavior in the case
that demotions fail.  Previous versions of this patch may have simply
failed to reclaim pages which were eligible for demotion but were unable
to be demoted in practice.

For some cases, for example, MADV_PAGEOUT, the pages are always discarded
instead of demoted to follow the kernel API definition.  Because
MADV_PAGEOUT is defined as freeing specified pages regardless in which
tier they are.

Note: This just adds the start of infrastructure for migration.  It is
actually disabled next to the FIXME in migrate_demote_page_ok().

[dave.hansen@linux.intel.com: v11]
  Link: https://lkml.kernel.org/r/20210715055145.195411-5-ying.huang@intel.com
  Link: https://lkml.kernel.org/r/20210721063926.3024591-4-ying.huang@intel.com

Link: https://lkml.kernel.org/r/20210715055145.195411-5-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Wei Xu <weixugc@google.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Yang Shi
5ac95884a7 mm/migrate: enable returning precise migrate_pages() success count
Under normal circumstances, migrate_pages() returns the number of pages
migrated.  In error conditions, it returns an error code.  When returning
an error code, there is no way to know how many pages were migrated or not
migrated.

Make migrate_pages() return how many pages are demoted successfully for
all cases, including when encountering errors.  Page reclaim behavior will
depend on this in subsequent patches.

Link: https://lkml.kernel.org/r/20210721063926.3024591-3-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-4-ying.huang@intel.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Oscar Salvador <osalvador@suse.de> [optional parameter]
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
Dave Hansen
884a6e5d1f mm/migrate: update node demotion order on hotplug events
Reclaim-based migration is attempting to optimize data placement in memory
based on the system topology.  If the system changes, so must the
migration ordering.

The implementation is conceptually simple and entirely unoptimized.  On
any memory or CPU hotplug events, assume that a node was added or removed
and recalculate all migration targets.  This ensures that the
node_demotion[] array is always ready to be used in case the new reclaim
mode is enabled.

This recalculation is far from optimal, most glaringly that it does not
even attempt to figure out the hotplug event would have some *actual*
effect on the demotion order.  But, given the expected paucity of hotplug
events, this should be fine.

Link: https://lkml.kernel.org/r/20210721063926.3024591-2-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-3-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00