[RFC PATCH 00/18] use struct ptdesc to replace pgtable_t

alexs
2024-07-30T06:42:57Z

We have struct ptdesc for page table descriptor a year ago, but it
has no much usages in kernel, while pgtable_t is used widely.

The pgtable_t is typedefed as 'pte_t *' in sparc, s390, powerpc and m68k
except SUN3, others archs are all same as 'struct page *'.

These blocks the conception and code update for page table descriptor to
struct ptdesc.

So, the simple idea to push the ptdesc conception forward is to update
all pgtable_t by ptdesc or pte_t pointer. But this needs widely
knowledges for most all of different archs. Common code change is easy
for include/ and mm/ directory, but it's hard in all archs.

Thanks for intel LKP framework, I fixed most all of build issues except
a bug on powerpc which reports a "struct ptdesc *" incompatible with
struct ptdesc *' pointer issue...

Another trouble is pmd_pgtable() conversion in the last patch.
Maybe some of arch need define theirself own pmd_ptdesc()?

This patchset is immature, even except above 2 issues, I just tested
virutal machine booting and kselftest mm on x86 and arm64.

Anyway any input are appreciated!

Thanks
Alex

Alex Shi (18):
mm/pgtable: use ptdesc in pte_free_now/pte_free_defer
mm/pgtable: convert ptdesc.pmd_huge_pte to ptdesc pointer
fs/dax: use ptdesc in dax_pmd_load_hole
mm/thp: use ptdesc pointer in __do_huge_pmd_anonymous_page
mm/thp: use ptdesc in do_huge_pmd_anonymous_page
mm/thp: convert insert_pfn_pmd and its caller to use ptdesc
mm/thp: use ptdesc in copy_huge_pmd
mm/memory: use ptdesc in __pte_alloc
mm/pgtable: fully use ptdesc in pte_alloc_one series functions
mm/pgtable: pass ptdesc to pte_free()
mm/pgtable: introduce ptdesc_pfn and use ptdesc in free_pte_range()
mm/thp: pass ptdesc to set_huge_zero_folio function
mm/pgtable: return ptdesc pointer in pgtable_trans_huge_withdraw
mm/pgtable: use ptdesc in pgtable_trans_huge_deposit
mm/pgtable: pass ptdesc to pmd_populate
mm/pgtable: pass ptdesc to pmd_install
mm: convert vmf.prealloc_pte to struct ptdesc pointer
mm/pgtable: pass ptdesc in pte_free_defer

arch/alpha/include/asm/pgalloc.h | 4 +-
arch/arc/include/asm/pgalloc.h | 4 +-
arch/arm/include/asm/pgalloc.h | 13 +--
arch/arm/include/asm/tlb.h | 4 +-
arch/arm/mm/pgd.c | 2 +-
arch/arm64/include/asm/pgalloc.h | 4 +-
arch/arm64/include/asm/tlb.h | 4 +-
arch/csky/include/asm/pgalloc.h | 4 +-
arch/hexagon/include/asm/pgalloc.h | 8 +-
arch/loongarch/include/asm/pgalloc.h | 8 +-
arch/m68k/include/asm/motorola_pgalloc.h | 12 +-
arch/m68k/include/asm/sun3_pgalloc.h | 4 +-
arch/microblaze/include/asm/pgalloc.h | 2 +-
arch/mips/include/asm/pgalloc.h | 4 +-
arch/nios2/include/asm/pgalloc.h | 4 +-
arch/openrisc/include/asm/pgalloc.h | 8 +-
arch/parisc/include/asm/pgalloc.h | 2 +-
arch/powerpc/include/asm/book3s/32/pgalloc.h | 4 +-
arch/powerpc/include/asm/book3s/64/hash-4k.h | 4 +-
arch/powerpc/include/asm/book3s/64/hash-64k.h | 4 +-
arch/powerpc/include/asm/book3s/64/pgalloc.h | 4 +-
arch/powerpc/include/asm/book3s/64/pgtable.h | 8 +-
arch/powerpc/include/asm/book3s/64/radix.h | 4 +-
arch/powerpc/include/asm/pgalloc.h | 8 +-
arch/powerpc/mm/book3s64/hash_pgtable.c | 10 +-
arch/powerpc/mm/book3s64/radix_pgtable.c | 10 +-
arch/riscv/include/asm/pgalloc.h | 8 +-
arch/s390/include/asm/pgalloc.h | 4 +-
arch/s390/include/asm/pgtable.h | 4 +-
arch/s390/mm/pgalloc.c | 2 +-
arch/s390/mm/pgtable.c | 14 +--
arch/sh/include/asm/pgalloc.h | 4 +-
arch/sparc/include/asm/pgalloc_32.h | 6 +-
arch/sparc/include/asm/pgalloc_64.h | 2 +-
arch/sparc/include/asm/pgtable_64.h | 4 +-
arch/sparc/mm/init_64.c | 2 +-
arch/sparc/mm/srmmu.c | 6 +-
arch/sparc/mm/tlb.c | 14 +--
arch/x86/include/asm/pgalloc.h | 10 +-
arch/x86/mm/pgtable.c | 8 +-
arch/xtensa/include/asm/pgalloc.h | 12 +-
fs/dax.c | 14 +--
include/asm-generic/pgalloc.h | 10 +-
include/linux/mm.h | 16 ++-
include/linux/mm_types.h | 4 +-
include/linux/pgtable.h | 6 +-
mm/debug_vm_pgtable.c | 6 +-
mm/huge_memory.c | 103 +++++++++---------
mm/internal.h | 2 +-
mm/khugepaged.c | 14 +--
mm/memory.c | 15 +--
mm/mremap.c | 2 +-
mm/pgtable-generic.c | 37 +++----
53 files changed, 240 insertions(+), 236 deletions(-)