From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/pgtable-generic.c: simplify the VM_BUG_ON condition in pmdp_huge_clear_flush() The condition (A && !C && !D) || !A is equivalent to !A || (A && !C && !D) and can be further simplified to !A || (!C && !D). Link: https://lkml.kernel.org/r/20210201114319.34720-1-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/pgtable-generic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/pgtable-generic.c~mm-simplify-the-vm_bug_on-condition-in-pmdp_huge_clear_flush +++ a/mm/pgtable-generic.c @@ -135,8 +135,8 @@ pmd_t pmdp_huge_clear_flush(struct vm_ar { pmd_t pmd; VM_BUG_ON(address & ~HPAGE_PMD_MASK); - VM_BUG_ON((pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) && - !pmd_devmap(*pmdp)) || !pmd_present(*pmdp)); + VM_BUG_ON(!pmd_present(*pmdp) || (!pmd_trans_huge(*pmdp) && + !pmd_devmap(*pmdp))); pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); return pmd; _
