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    Subject[PATCH 01/25] mm/um: Fix extra accounting for page fault retries
    Date
    When page fault retried, we should only do the accounting once rather than once
    for each page fault retry.

    CC: Jeff Dike <jdike@addtoit.com>
    CC: Richard Weinberger <richard@nod.at>
    CC: Anton Ivanov <anton.ivanov@cambridgegreys.com>
    CC: linux-um@lists.infradead.org
    Signed-off-by: Peter Xu <peterx@redhat.com>
    ---
    arch/um/kernel/trap.c | 13 +++++++------
    1 file changed, 7 insertions(+), 6 deletions(-)

    diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
    index 8f18cf56b3dd..d162168490d1 100644
    --- a/arch/um/kernel/trap.c
    +++ b/arch/um/kernel/trap.c
    @@ -34,6 +34,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
    pte_t *pte;
    int err = -EFAULT;
    unsigned int flags = FAULT_FLAG_DEFAULT;
    + vm_fault_t fault, major = 0;

    *code_out = SEGV_MAPERR;

    @@ -73,9 +74,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
    }

    do {
    - vm_fault_t fault;
    -
    fault = handle_mm_fault(vma, address, flags);
    + major |= fault & VM_FAULT_MAJOR;

    if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
    goto out_nosemaphore;
    @@ -92,10 +92,6 @@ int handle_page_fault(unsigned long address, unsigned long ip,
    BUG();
    }
    if (flags & FAULT_FLAG_ALLOW_RETRY) {
    - if (fault & VM_FAULT_MAJOR)
    - current->maj_flt++;
    - else
    - current->min_flt++;
    if (fault & VM_FAULT_RETRY) {
    flags |= FAULT_FLAG_TRIED;

    @@ -103,6 +99,11 @@ int handle_page_fault(unsigned long address, unsigned long ip,
    }
    }

    + if (major)
    + current->maj_flt++;
    + else
    + current->min_flt++;
    +
    pgd = pgd_offset(mm, address);
    p4d = p4d_offset(pgd, address);
    pud = pud_offset(p4d, address);
    --
    2.26.2
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