[PATCH v2 0/7] arch/mm/fault: accelerate pagefault when badaccess

[Kefeng Wang <wangkefeng.wang@huawei.com>]

After VMA lock-based page fault handling enabled, if bad access met
under per-vma lock, it will fallback to mmap_lock-based handling,
so it leads to unnessary mmap lock and vma find again. A test from
lmbench shows 34% improve after this changes on arm64,

  lat_sig -P 1 prot lat_sig 0.29194 -> 0.19198

Only build test on other archs except arm64.

v2: 
- a better changelog, and describe the counting changes, suggested by
  Suren Baghdasaryan
- add RB

Kefeng Wang (7):
  arm64: mm: cleanup __do_page_fault()
  arm64: mm: accelerate pagefault when VM_FAULT_BADACCESS
  arm: mm: accelerate pagefault when VM_FAULT_BADACCESS
  powerpc: mm: accelerate pagefault when badaccess
  riscv: mm: accelerate pagefault when badaccess
  s390: mm: accelerate pagefault when badaccess
  x86: mm: accelerate pagefault when badaccess

 arch/arm/mm/fault.c     |  4 +++-
 arch/arm64/mm/fault.c   | 31 ++++++++++---------------------
 arch/powerpc/mm/fault.c | 33 ++++++++++++++++++++-------------
 arch/riscv/mm/fault.c   |  5 ++++-
 arch/s390/mm/fault.c    |  3 ++-
 arch/x86/mm/fault.c     | 23 ++++++++++++++---------
 6 files changed, 53 insertions(+), 46 deletions(-)

-- 
2.27.0