powerpc/mm/book3s: Check for pmd_large instead of pmd_trans_huge (ae28f17b) · Commits · 戴 / test

Update few code paths to check for pmd_large. set_pmd_at: We want to use this to store swap pte at pmd level. For swap ptes we don't want to set H_PAGE_THP_HUGE. Hence check for pmd_large in set_pmd_at. This remove the false WARN_ON when using this with swap pmd entry. pmd_page: We don't really use them on pmd migration entries. But they can also work with migration entries and we don't differentiate at the pte level. Hence update pmd_page to work with pmd migration entries too __find_linux_pte: lockless page table walk need to handle pmd migration entries. pmd_trans_huge check will return false on them. We don't set thp = 1 for such entries, but update hpage_shift correctly. Without this we will walk pmd migration entries as a pte page pointer which is wrong. Signed-off-by:

Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:

Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/hugetlbpage.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -837,8 +837,12 @@ pte_t __find_linux_pte(pgd_t pgdir, unsigned long ea,
		ret_pte = (pte_t *) pmdp;
		goto out;
		}

		if (pmd_huge(pmd)) {
		/*
		* pmd_large check below will handle the swap pmd pte
		* we need to do both the check because they are config
		* dependent.
		*/
		if (pmd_huge(pmd) \|\| pmd_large(pmd)) {
		ret_pte = (pte_t *) pmdp;
		goto out;
		} else if (is_hugepd(__hugepd(pmd_val(pmd))))

arch/powerpc/mm/pgtable-book3s64.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -75,7 +75,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
		*/
		WARN_ON(pte_val(pmd_pte(*pmdp)) & _PAGE_PRESENT);
		assert_spin_locked(pmd_lockptr(mm, pmdp));
		WARN_ON(!(pmd_trans_huge(pmd) \|\| pmd_devmap(pmd)));
		WARN_ON(!(pmd_large(pmd) \|\| pmd_devmap(pmd)));
		#endif
		trace_hugepage_set_pmd(addr, pmd_val(pmd));
		return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));

arch/powerpc/mm/pgtable_64.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -306,7 +306,7 @@ struct page *pud_page(pud_t pud)
		*/
		struct page *pmd_page(pmd_t pmd)
		{
		if (pmd_trans_huge(pmd) \|\| pmd_huge(pmd) \|\| pmd_devmap(pmd))
		if (pmd_large(pmd) \|\| pmd_huge(pmd) \|\| pmd_devmap(pmd))
		return pte_page(pmd_pte(pmd));
		return virt_to_page(pmd_page_vaddr(pmd));
		}

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