mm: introduce do_set_pmd() (10102459) · Commits · 戴 / test

include/linux/huge_mm.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -143,6 +143,8 @@ static inline bool is_huge_zero_pmd(pmd_t pmd)
		struct page *get_huge_zero_page(void);
		void put_huge_zero_page(void);

		#define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))

		#else /* CONFIG_TRANSPARENT_HUGEPAGE */
		#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
		#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })

mm/huge_memory.c

+0 −5

Original line number	Diff line number	Diff line
		@@ -796,11 +796,6 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
		return pmd;
		}

		static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot)
		{
		return pmd_mkhuge(mk_pmd(page, prot));
		}

		static inline struct list_head page_deferred_list(struct page page)
		{
		/*

mm/memory.c

+71 −1

Original line number	Diff line number	Diff line
		@@ -2920,6 +2920,66 @@ map_pte:
		return 0;
		}

		#ifdef CONFIG_TRANSPARENT_HUGEPAGE

		#define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1)
		static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
		unsigned long haddr)
		{
		if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
		(vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK))
		return false;
		if (haddr < vma->vm_start \|\| haddr + HPAGE_PMD_SIZE > vma->vm_end)
		return false;
		return true;
		}

		static int do_set_pmd(struct fault_env fe, struct page page)
		{
		struct vm_area_struct *vma = fe->vma;
		bool write = fe->flags & FAULT_FLAG_WRITE;
		unsigned long haddr = fe->address & HPAGE_PMD_MASK;
		pmd_t entry;
		int i, ret;

		if (!transhuge_vma_suitable(vma, haddr))
		return VM_FAULT_FALLBACK;

		ret = VM_FAULT_FALLBACK;
		page = compound_head(page);

		fe->ptl = pmd_lock(vma->vm_mm, fe->pmd);
		if (unlikely(!pmd_none(*fe->pmd)))
		goto out;

		for (i = 0; i < HPAGE_PMD_NR; i++)
		flush_icache_page(vma, page + i);

		entry = mk_huge_pmd(page, vma->vm_page_prot);
		if (write)
		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);

		add_mm_counter(vma->vm_mm, MM_FILEPAGES, HPAGE_PMD_NR);
		page_add_file_rmap(page, true);

		set_pmd_at(vma->vm_mm, haddr, fe->pmd, entry);

		update_mmu_cache_pmd(vma, haddr, fe->pmd);

		/* fault is handled */
		ret = 0;
		out:
		spin_unlock(fe->ptl);
		return ret;
		}
		#else
		static int do_set_pmd(struct fault_env fe, struct page page)
		{
		BUILD_BUG();
		return 0;
		}
		#endif

		/**
		* alloc_set_pte - setup new PTE entry for given page and add reverse page
		* mapping. If needed, the fucntion allocates page table or use pre-allocated.
		@@ -2939,9 +2999,19 @@ int alloc_set_pte(struct fault_env fe, struct mem_cgroup memcg,
		struct vm_area_struct *vma = fe->vma;
		bool write = fe->flags & FAULT_FLAG_WRITE;
		pte_t entry;
		int ret;

		if (pmd_none(*fe->pmd) && PageTransCompound(page)) {
		/* THP on COW? */
		VM_BUG_ON_PAGE(memcg, page);

		ret = do_set_pmd(fe, page);
		if (ret != VM_FAULT_FALLBACK)
		return ret;
		}

		if (!fe->pte) {
		int ret = pte_alloc_one_map(fe);
		ret = pte_alloc_one_map(fe);
		if (ret)
		return ret;
		}

mm/migrate.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -1986,8 +1986,7 @@ fail_putback:
		}

		orig_entry = *pmd;
		entry = mk_pmd(new_page, vma->vm_page_prot);
		entry = pmd_mkhuge(entry);
		entry = mk_huge_pmd(new_page, vma->vm_page_prot);
		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);

		/*

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