From ab6e3d0939bb332d72444a532f0f72e0dfde7b7b Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Fri, 8 Sep 2017 16:11:04 -0700 Subject: mm: soft-dirty: keep soft-dirty bits over thp migration Soft dirty bit is designed to keep tracked over page migration. This patch makes it work in the same manner for thp migration too. Signed-off-by: Naoya Horiguchi Signed-off-by: Zi Yan Cc: "H. Peter Anvin" Cc: Anshuman Khandual Cc: Dave Hansen Cc: David Nellans Cc: Ingo Molnar Cc: Kirill A. Shutemov Cc: Mel Gorman Cc: Minchan Kim Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Andrea Arcangeli Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) (limited to 'mm') diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b82585eabe85..269b5df58543 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -937,6 +937,8 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, if (is_write_migration_entry(entry)) { make_migration_entry_read(&entry); pmd = swp_entry_to_pmd(entry); + if (pmd_swp_soft_dirty(*src_pmd)) + pmd = pmd_swp_mksoft_dirty(pmd); set_pmd_at(src_mm, addr, src_pmd, pmd); } set_pmd_at(dst_mm, addr, dst_pmd, pmd); @@ -1756,6 +1758,17 @@ static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl, } #endif +static pmd_t move_soft_dirty_pmd(pmd_t pmd) +{ +#ifdef CONFIG_MEM_SOFT_DIRTY + if (unlikely(is_pmd_migration_entry(pmd))) + pmd = pmd_swp_mksoft_dirty(pmd); + else if (pmd_present(pmd)) + pmd = pmd_mksoft_dirty(pmd); +#endif + return pmd; +} + bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, unsigned long new_addr, unsigned long old_end, pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush) @@ -1798,7 +1811,8 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); pgtable_trans_huge_deposit(mm, new_pmd, pgtable); } - set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd)); + pmd = move_soft_dirty_pmd(pmd); + set_pmd_at(mm, new_addr, new_pmd, pmd); if (new_ptl != old_ptl) spin_unlock(new_ptl); if (force_flush) @@ -1846,6 +1860,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, */ make_migration_entry_read(&entry); newpmd = swp_entry_to_pmd(entry); + if (pmd_swp_soft_dirty(*pmd)) + newpmd = pmd_swp_mksoft_dirty(newpmd); set_pmd_at(mm, addr, pmd, newpmd); } goto unlock; @@ -2824,6 +2840,7 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, unsigned long address = pvmw->address; pmd_t pmdval; swp_entry_t entry; + pmd_t pmdswp; if (!(pvmw->pmd && !pvmw->pte)) return; @@ -2837,8 +2854,10 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, if (pmd_dirty(pmdval)) set_page_dirty(page); entry = make_migration_entry(page, pmd_write(pmdval)); - pmdval = swp_entry_to_pmd(entry); - set_pmd_at(mm, address, pvmw->pmd, pmdval); + pmdswp = swp_entry_to_pmd(entry); + if (pmd_soft_dirty(pmdval)) + pmdswp = pmd_swp_mksoft_dirty(pmdswp); + set_pmd_at(mm, address, pvmw->pmd, pmdswp); page_remove_rmap(page, true); put_page(page); @@ -2861,6 +2880,8 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) entry = pmd_to_swp_entry(*pvmw->pmd); get_page(new); pmde = pmd_mkold(mk_huge_pmd(new, vma->vm_page_prot)); + if (pmd_swp_soft_dirty(*pvmw->pmd)) + pmde = pmd_mksoft_dirty(pmde); if (is_write_migration_entry(entry)) pmde = maybe_pmd_mkwrite(pmde, vma); -- cgit