From f55e1014f9e567d830eb3a7f57d879a34872af4b Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 29 Nov 2017 09:01:01 -0800 Subject: Revert "mm, thp: Do not make pmd/pud dirty without a reason" This reverts commit 152e93af3cfe2d29d8136cc0a02a8612507136ee. It was a nice cleanup in theory, but as Nicolai Stange points out, we do need to make the page dirty for the copy-on-write case even when we didn't end up making it writable, since the dirty bit is what we use to check that we've gone through a COW cycle. Reported-by: Michal Hocko Acked-by: Kirill A. Shutemov Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 31 ++++++++++++------------------- 1 file changed, 12 insertions(+), 19 deletions(-) (limited to 'mm/huge_memory.c') diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f22401fd83b5..0e7ded98d114 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -474,13 +474,10 @@ out: } __setup("transparent_hugepage=", setup_transparent_hugepage); -pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma, bool dirty) +pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { - if (likely(vma->vm_flags & VM_WRITE)) { + if (likely(vma->vm_flags & VM_WRITE)) pmd = pmd_mkwrite(pmd); - if (dirty) - pmd = pmd_mkdirty(pmd); - } return pmd; } @@ -602,7 +599,7 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, } entry = mk_huge_pmd(page, vma->vm_page_prot); - entry = maybe_pmd_mkwrite(entry, vma, true); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); page_add_new_anon_rmap(page, vma, haddr, true); mem_cgroup_commit_charge(page, memcg, false, true); lru_cache_add_active_or_unevictable(page, vma); @@ -744,8 +741,8 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, if (pfn_t_devmap(pfn)) entry = pmd_mkdevmap(entry); if (write) { - entry = pmd_mkyoung(entry); - entry = maybe_pmd_mkwrite(entry, vma, true); + entry = pmd_mkyoung(pmd_mkdirty(entry)); + entry = maybe_pmd_mkwrite(entry, vma); } if (pgtable) { @@ -791,14 +788,10 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD -static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma, - bool dirty) +static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma) { - if (likely(vma->vm_flags & VM_WRITE)) { + if (likely(vma->vm_flags & VM_WRITE)) pud = pud_mkwrite(pud); - if (dirty) - pud = pud_mkdirty(pud); - } return pud; } @@ -814,8 +807,8 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, if (pfn_t_devmap(pfn)) entry = pud_mkdevmap(entry); if (write) { - entry = pud_mkyoung(entry); - entry = maybe_pud_mkwrite(entry, vma, true); + entry = pud_mkyoung(pud_mkdirty(entry)); + entry = maybe_pud_mkwrite(entry, vma); } set_pud_at(mm, addr, pud, entry); update_mmu_cache_pud(vma, addr, pud); @@ -1286,7 +1279,7 @@ int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd) if (reuse_swap_page(page, NULL)) { pmd_t entry; entry = pmd_mkyoung(orig_pmd); - entry = maybe_pmd_mkwrite(entry, vma, true); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1)) update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); ret |= VM_FAULT_WRITE; @@ -1356,7 +1349,7 @@ alloc: } else { pmd_t entry; entry = mk_huge_pmd(new_page, vma->vm_page_prot); - entry = maybe_pmd_mkwrite(entry, vma, true); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); pmdp_huge_clear_flush_notify(vma, haddr, vmf->pmd); page_add_new_anon_rmap(new_page, vma, haddr, true); mem_cgroup_commit_charge(new_page, memcg, false, true); @@ -2935,7 +2928,7 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) if (pmd_swp_soft_dirty(*pvmw->pmd)) pmde = pmd_mksoft_dirty(pmde); if (is_write_migration_entry(entry)) - pmde = maybe_pmd_mkwrite(pmde, vma, false); + pmde = maybe_pmd_mkwrite(pmde, vma); flush_cache_range(vma, mmun_start, mmun_start + HPAGE_PMD_SIZE); page_add_anon_rmap(new, vma, mmun_start, true); -- cgit