[PATCH] mm: simplify the VM_BUG_ON condition in pmdp_huge_clear_flush()

From: Miaohe Lin
Date: Mon Feb 01 2021 - 06:44:53 EST


The condition (A && !C && !D) || !A is equivalent to !A || (A && !C && !D)
and can be further simplified to !A || (!C && !D).

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/pgtable-generic.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 9578db83e312..fa1375f3e3b2 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -135,8 +135,8 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
{
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;
--
2.19.1