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Commit 479f0abb authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
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thp: zap_huge_pmd(): zap huge zero pmd 



We don't have a mapped page to zap in huge zero page case.  Let's just clear
pmd and remove it from tlb.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4a6c1297

mm/huge_memory.c

+13 −8
Original line number Diff line number Diff line
@@ -1085,8 +1085,12 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, 
		pmd_t orig_pmd;

		pgtable = pgtable_trans_huge_withdraw(tlb->mm);

		orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);

		page = pmd_page(orig_pmd);

		tlb_remove_pmd_tlb_entry(tlb, pmd, addr);

		if (is_huge_zero_pmd(orig_pmd)) {

			tlb->mm->nr_ptes--;

			spin_unlock(&tlb->mm->page_table_lock);

		} else {

			page = pmd_page(orig_pmd);

			page_remove_rmap(page);

			VM_BUG_ON(page_mapcount(page) < 0);

			add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
@@ -1094,6 +1098,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, 
			tlb->mm->nr_ptes--;

			spin_unlock(&tlb->mm->page_table_lock);

			tlb_remove_page(tlb, page);

		}

		pte_free(tlb->mm, pgtable);

		ret = 1;

	}