[PATCH v4 00/36] New page table range API

From: Matthew Wilcox (Oracle)
Date: Wed Mar 15 2023 - 01:16:45 EST


This patchset changes the API used by the MM to set up page table entries.
The four APIs are:
set_ptes(mm, addr, ptep, pte, nr)
update_mmu_cache_range(vma, addr, ptep, nr)
flush_dcache_folio(folio)
flush_icache_pages(vma, page, nr)

flush_dcache_folio() isn't technically new, but no architecture
implemented it, so I've done that for you. The old APIs remain around
but are mostly implemented by calling the new interfaces.

The new APIs are based around setting up N page table entries at once.
The N entries belong to the same PMD, the same folio and the same VMA,
so ptep++ is a legitimate operation, and locking is taken care of for
you. Some architectures can do a better job of it than just a loop,
but I have hesitated to make too deep a change to architectures I don't
understand well.

One thing I have changed in every architecture is that PG_arch_1 is now a
per-folio bit instead of a per-page bit. This was something that would
have to happen eventually, and it makes sense to do it now rather than
iterate over every page involved in a cache flush and figure out if it
needs to happen.

The point of all this is better performance, and Fengwei Yin has
measured improvement on x86. I suspect you'll see improvement on
your architecture too. Try the new will-it-scale test mentioned here:
https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@xxxxxxxxx/
You'll need to run it on an XFS filesystem and have
CONFIG_TRANSPARENT_HUGEPAGE set.

For testing, I've only run the code on x86. If an x86->foo compiler
exists in Debian, I've built defconfig. I'm relying on the buildbots
to tell me what I missed, and people who actually have the hardware to
tell me if it actually works.

I'd like to get this into the MM tree soon, so quick feedback would
be appreciated.

v4:
- Fix a few compile errors (mostly Mike Rapoport)
- Incorporate Mike's suggestion to avoid having to define set_ptes()
or set_pte_at() on the majority of architectures
- Optimise m68k's __flush_pages_to_ram (Geert Uytterhoeven)
- Fix sun3 (me)
- Fix sparc32 (me)
- Pick up a few more Ack/Reviewed tags

v3:
- Reinstate flush_dcache_icache_phys() on PowerPC
- Fix folio_flush_mapping(). The documentation was correct and the
implementation was completely wrong
- Change the flush_dcache_page() documentation to describe
flush_dcache_folio() instead
- Split ARM from ARC. I messed up my git commands
- Remove page_mapping_file()
- Rationalise how flush_icache_pages() and flush_icache_page() are defined
- Use flush_icache_pages() in do_set_pmd()
- Pick up Guo Ren's Ack for csky

Matthew Wilcox (Oracle) (32):
mm: Convert page_table_check_pte_set() to page_table_check_ptes_set()
mm: Add generic flush_icache_pages() and documentation
mm: Add folio_flush_mapping()
mm: Remove ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO
mm: Add default definition of set_ptes()
alpha: Implement the new page table range API
arc: Implement the new page table range API
arm: Implement the new page table range API
arm64: Implement the new page table range API
csky: Implement the new page table range API
hexagon: Implement the new page table range API
ia64: Implement the new page table range API
loongarch: Implement the new page table range API
m68k: Implement the new page table range API
microblaze: Implement the new page table range API
mips: Implement the new page table range API
nios2: Implement the new page table range API
openrisc: Implement the new page table range API
parisc: Implement the new page table range API
powerpc: Implement the new page table range API
riscv: Implement the new page table range API
s390: Implement the new page table range API
superh: Implement the new page table range API
sparc32: Implement the new page table range API
sparc64: Implement the new page table range API
um: Implement the new page table range API
x86: Implement the new page table range API
xtensa: Implement the new page table range API
mm: Remove page_mapping_file()
mm: Rationalise flush_icache_pages() and flush_icache_page()
mm: Tidy up set_ptes definition
mm: Use flush_icache_pages() in do_set_pmd()

Yin Fengwei (4):
filemap: Add filemap_map_folio_range()
rmap: add folio_add_file_rmap_range()
mm: Convert do_set_pte() to set_pte_range()
filemap: Batch PTE mappings

Documentation/core-api/cachetlb.rst | 51 +++++-----
Documentation/filesystems/locking.rst | 2 +-
arch/alpha/include/asm/cacheflush.h | 13 ++-
arch/alpha/include/asm/pgtable.h | 9 +-
arch/arc/include/asm/cacheflush.h | 14 +--
arch/arc/include/asm/pgtable-bits-arcv2.h | 11 +--
arch/arc/include/asm/pgtable-levels.h | 1 +
arch/arc/mm/cache.c | 61 +++++++-----
arch/arc/mm/tlb.c | 18 ++--
arch/arm/include/asm/cacheflush.h | 29 +++---
arch/arm/include/asm/pgtable.h | 5 +-
arch/arm/include/asm/tlbflush.h | 13 ++-
arch/arm/mm/copypage-v4mc.c | 5 +-
arch/arm/mm/copypage-v6.c | 5 +-
arch/arm/mm/copypage-xscale.c | 5 +-
arch/arm/mm/dma-mapping.c | 24 ++---
arch/arm/mm/fault-armv.c | 14 +--
arch/arm/mm/flush.c | 99 +++++++++++--------
arch/arm/mm/mm.h | 2 +-
arch/arm/mm/mmu.c | 14 ++-
arch/arm64/include/asm/cacheflush.h | 4 +-
arch/arm64/include/asm/pgtable.h | 25 +++--
arch/arm64/mm/flush.c | 36 +++----
arch/csky/abiv1/cacheflush.c | 32 ++++---
arch/csky/abiv1/inc/abi/cacheflush.h | 3 +-
arch/csky/abiv2/cacheflush.c | 32 +++----
arch/csky/abiv2/inc/abi/cacheflush.h | 11 ++-
arch/csky/include/asm/pgtable.h | 8 +-
arch/hexagon/include/asm/cacheflush.h | 9 +-
arch/hexagon/include/asm/pgtable.h | 9 +-
arch/ia64/hp/common/sba_iommu.c | 26 ++---
arch/ia64/include/asm/cacheflush.h | 14 ++-
arch/ia64/include/asm/pgtable.h | 4 +-
arch/ia64/mm/init.c | 28 ++++--
arch/loongarch/include/asm/cacheflush.h | 2 +-
arch/loongarch/include/asm/pgtable-bits.h | 4 +-
arch/loongarch/include/asm/pgtable.h | 28 +++---
arch/loongarch/mm/pgtable.c | 2 +-
arch/loongarch/mm/tlb.c | 2 +-
arch/m68k/include/asm/cacheflush_mm.h | 26 +++--
arch/m68k/include/asm/mcf_pgtable.h | 1 +
arch/m68k/include/asm/motorola_pgtable.h | 1 +
arch/m68k/include/asm/pgtable_mm.h | 9 +-
arch/m68k/include/asm/sun3_pgtable.h | 1 +
arch/m68k/mm/motorola.c | 2 +-
arch/microblaze/include/asm/cacheflush.h | 8 ++
arch/microblaze/include/asm/pgtable.h | 15 +--
arch/microblaze/include/asm/tlbflush.h | 4 +-
arch/mips/bcm47xx/prom.c | 2 +-
arch/mips/include/asm/cacheflush.h | 32 ++++---
arch/mips/include/asm/pgtable-32.h | 10 +-
arch/mips/include/asm/pgtable-64.h | 6 +-
arch/mips/include/asm/pgtable-bits.h | 6 +-
arch/mips/include/asm/pgtable.h | 44 +++++----
arch/mips/mm/c-r4k.c | 5 +-
arch/mips/mm/cache.c | 56 +++++------
arch/mips/mm/init.c | 21 ++--
arch/mips/mm/pgtable-32.c | 2 +-
arch/mips/mm/pgtable-64.c | 2 +-
arch/mips/mm/tlbex.c | 2 +-
arch/nios2/include/asm/cacheflush.h | 6 +-
arch/nios2/include/asm/pgtable.h | 28 ++++--
arch/nios2/mm/cacheflush.c | 62 ++++++------
arch/openrisc/include/asm/cacheflush.h | 8 +-
arch/openrisc/include/asm/pgtable.h | 14 ++-
arch/openrisc/mm/cache.c | 12 ++-
arch/parisc/include/asm/cacheflush.h | 14 ++-
arch/parisc/include/asm/pgtable.h | 37 +++++---
arch/parisc/kernel/cache.c | 101 ++++++++++++++------
arch/powerpc/include/asm/book3s/pgtable.h | 10 +-
arch/powerpc/include/asm/cacheflush.h | 14 ++-
arch/powerpc/include/asm/kvm_ppc.h | 10 +-
arch/powerpc/include/asm/nohash/pgtable.h | 13 +--
arch/powerpc/include/asm/pgtable.h | 6 ++
arch/powerpc/mm/book3s64/hash_utils.c | 11 ++-
arch/powerpc/mm/cacheflush.c | 40 +++-----
arch/powerpc/mm/nohash/e500_hugetlbpage.c | 3 +-
arch/powerpc/mm/pgtable.c | 51 +++++-----
arch/riscv/include/asm/cacheflush.h | 19 ++--
arch/riscv/include/asm/pgtable.h | 26 +++--
arch/riscv/mm/cacheflush.c | 11 +--
arch/s390/include/asm/pgtable.h | 33 +++++--
arch/sh/include/asm/cacheflush.h | 21 ++--
arch/sh/include/asm/pgtable.h | 6 +-
arch/sh/include/asm/pgtable_32.h | 5 +-
arch/sh/mm/cache-j2.c | 4 +-
arch/sh/mm/cache-sh4.c | 26 +++--
arch/sh/mm/cache-sh7705.c | 26 +++--
arch/sh/mm/cache.c | 52 +++++-----
arch/sh/mm/kmap.c | 3 +-
arch/sparc/include/asm/cacheflush_32.h | 9 +-
arch/sparc/include/asm/cacheflush_64.h | 19 ++--
arch/sparc/include/asm/pgtable_32.h | 8 +-
arch/sparc/include/asm/pgtable_64.h | 24 ++++-
arch/sparc/kernel/smp_64.c | 56 +++++++----
arch/sparc/mm/init_32.c | 13 ++-
arch/sparc/mm/init_64.c | 78 ++++++++-------
arch/sparc/mm/tlb.c | 5 +-
arch/um/include/asm/pgtable.h | 7 +-
arch/x86/include/asm/pgtable.h | 13 ++-
arch/xtensa/include/asm/cacheflush.h | 11 ++-
arch/xtensa/include/asm/pgtable.h | 17 ++--
arch/xtensa/mm/cache.c | 83 +++++++++-------
include/asm-generic/cacheflush.h | 7 --
include/linux/cacheflush.h | 13 ++-
include/linux/mm.h | 3 +-
include/linux/page_table_check.h | 14 +--
include/linux/pagemap.h | 28 ++++--
include/linux/pgtable.h | 31 ++++++
include/linux/rmap.h | 2 +
mm/filemap.c | 111 +++++++++++++---------
mm/memory.c | 31 +++---
mm/page_table_check.c | 14 +--
mm/rmap.c | 60 +++++++++---
mm/util.c | 2 +-
115 files changed, 1344 insertions(+), 916 deletions(-)

--
2.39.2