![Gerald Schaefer](/assets/img/avatar_default.png)
The thp page table pre-allocation code currently assumes that pgtable_t is of type "struct page *". This may not be true for all architectures, so this patch removes that assumption by replacing the functions prepare_pmd_huge_pte() and get_pmd_huge_pte() with two new functions that can be defined architecture-specific. It also removes two VM_BUG_ON checks for page_count() and page_mapcount() operating on a pgtable_t. Apart from the VM_BUG_ON removal, there will be no functional change introduced by this patch. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
162 lines
4.2 KiB
C
162 lines
4.2 KiB
C
/*
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* mm/pgtable-generic.c
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*
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* Generic pgtable methods declared in asm-generic/pgtable.h
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*
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* Copyright (C) 2010 Linus Torvalds
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*/
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#include <linux/pagemap.h>
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#include <asm/tlb.h>
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#include <asm-generic/pgtable.h>
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#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
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/*
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* Only sets the access flags (dirty, accessed, and
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* writable). Furthermore, we know it always gets set to a "more
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* permissive" setting, which allows most architectures to optimize
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* this. We return whether the PTE actually changed, which in turn
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* instructs the caller to do things like update__mmu_cache. This
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* used to be done in the caller, but sparc needs minor faults to
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* force that call on sun4c so we changed this macro slightly
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*/
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int ptep_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep,
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pte_t entry, int dirty)
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{
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int changed = !pte_same(*ptep, entry);
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if (changed) {
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set_pte_at(vma->vm_mm, address, ptep, entry);
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flush_tlb_page(vma, address);
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}
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return changed;
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}
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#endif
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#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
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int pmdp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp,
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pmd_t entry, int dirty)
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{
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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int changed = !pmd_same(*pmdp, entry);
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VM_BUG_ON(address & ~HPAGE_PMD_MASK);
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if (changed) {
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set_pmd_at(vma->vm_mm, address, pmdp, entry);
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flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
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}
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return changed;
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#else /* CONFIG_TRANSPARENT_HUGEPAGE */
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BUG();
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return 0;
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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}
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
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int ptep_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep)
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{
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int young;
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young = ptep_test_and_clear_young(vma, address, ptep);
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if (young)
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flush_tlb_page(vma, address);
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return young;
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}
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#endif
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#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
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int pmdp_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp)
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{
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int young;
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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VM_BUG_ON(address & ~HPAGE_PMD_MASK);
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#else
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BUG();
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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young = pmdp_test_and_clear_young(vma, address, pmdp);
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if (young)
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flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
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return young;
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}
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
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pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
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pte_t *ptep)
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{
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pte_t pte;
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pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
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flush_tlb_page(vma, address);
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return pte;
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}
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#endif
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#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
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pmd_t *pmdp)
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{
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pmd_t pmd;
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VM_BUG_ON(address & ~HPAGE_PMD_MASK);
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pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
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flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
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return pmd;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
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pmd_t *pmdp)
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{
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pmd_t pmd = pmd_mksplitting(*pmdp);
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VM_BUG_ON(address & ~HPAGE_PMD_MASK);
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set_pmd_at(vma->vm_mm, address, pmdp, pmd);
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/* tlb flush only to serialize against gup-fast */
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flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
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{
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assert_spin_locked(&mm->page_table_lock);
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/* FIFO */
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if (!mm->pmd_huge_pte)
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INIT_LIST_HEAD(&pgtable->lru);
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else
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list_add(&pgtable->lru, &mm->pmd_huge_pte->lru);
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mm->pmd_huge_pte = pgtable;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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/* no "address" argument so destroys page coloring of some arch */
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pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
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{
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pgtable_t pgtable;
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assert_spin_locked(&mm->page_table_lock);
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/* FIFO */
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pgtable = mm->pmd_huge_pte;
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if (list_empty(&pgtable->lru))
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mm->pmd_huge_pte = NULL;
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else {
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mm->pmd_huge_pte = list_entry(pgtable->lru.next,
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struct page, lru);
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list_del(&pgtable->lru);
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}
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return pgtable;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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