We have a 3x throughput improvement reported by Intel's kernel test
robot: https://lore.kernel.org/all/[email protected]/
This is from delaying taking the mmap_lock for page faults until we
actually need the mmap_lock in order to assign an anon_vma to the vma.
It cleans up the page fault path a little by making the anon fault
handler more similar to the file fault handler.
Matthew Wilcox (Oracle) (4):
mm: Assert the mmap_lock is held in __anon_vma_prepare()
mm: Delay the check for a NULL anon_vma
mm: Fix some minor per-VMA lock issues in userfaultfd
mm: Optimise vmf_anon_prepare() for VMAs without an anon_vma
mm/huge_memory.c | 6 ++++--
mm/memory.c | 42 +++++++++++++++++++++++++++---------------
mm/rmap.c | 3 +--
mm/userfaultfd.c | 20 +++++++++-----------
4 files changed, 41 insertions(+), 30 deletions(-)
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2.43.0