diff --git a/mm/madvise.c b/mm/madvise.c index 539ee3502dbf..703b68381241 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -40,6 +40,7 @@ struct madvise_walk_private { struct mmu_gather *tlb; bool pageout; + bool can_pageout_file; }; /* @@ -319,6 +320,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, struct madvise_walk_private *private = walk->private; struct mmu_gather *tlb = private->tlb; bool pageout = private->pageout; + bool pageout_anon_only = pageout && !private->can_pageout_file; struct mm_struct *mm = tlb->mm; struct vm_area_struct *vma = walk->vma; pte_t *orig_pte, *pte, ptent; @@ -355,6 +357,9 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, if (page_mapcount(page) != 1) goto huge_unlock; + if (pageout_anon_only && !PageAnon(page)) + goto huge_unlock; + if (next - addr != HPAGE_PMD_SIZE) { int err; @@ -423,6 +428,8 @@ regular_page: if (PageTransCompound(page)) { if (page_mapcount(page) != 1) break; + if (pageout_anon_only && !PageAnon(page)) + break; get_page(page); if (!trylock_page(page)) { put_page(page); @@ -450,6 +457,9 @@ regular_page: if (!PageLRU(page) || page_mapcount(page) != 1) continue; + if (pageout_anon_only && !PageAnon(page)) + continue; + VM_BUG_ON_PAGE(PageTransCompound(page), page); if (pte_young(ptent)) { @@ -527,11 +537,13 @@ static long madvise_cold(struct vm_area_struct *vma, static void madvise_pageout_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, - unsigned long addr, unsigned long end) + unsigned long addr, unsigned long end, + bool can_pageout_file) { struct madvise_walk_private walk_private = { .pageout = true, .tlb = tlb, + .can_pageout_file = can_pageout_file, }; tlb_start_vma(tlb, vma); @@ -539,10 +551,8 @@ static void madvise_pageout_page_range(struct mmu_gather *tlb, tlb_end_vma(tlb, vma); } -static inline bool can_do_pageout(struct vm_area_struct *vma) +static inline bool can_do_file_pageout(struct vm_area_struct *vma) { - if (vma_is_anonymous(vma)) - return true; if (!vma->vm_file) return false; /* @@ -562,17 +572,23 @@ static long madvise_pageout(struct vm_area_struct *vma, { struct mm_struct *mm = vma->vm_mm; struct mmu_gather tlb; + bool can_pageout_file; *prev = vma; if (!can_madv_lru_vma(vma)) return -EINVAL; - if (!can_do_pageout(vma)) - return 0; + /* + * If the VMA belongs to a private file mapping, there can be private + * dirty pages which can be paged out if even this process is neither + * owner nor write capable of the file. Cache the file access check + * here and use it later during page walk. + */ + can_pageout_file = can_do_file_pageout(vma); lru_add_drain(); tlb_gather_mmu(&tlb, mm); - madvise_pageout_page_range(&tlb, vma, start_addr, end_addr); + madvise_pageout_page_range(&tlb, vma, start_addr, end_addr, can_pageout_file); tlb_finish_mmu(&tlb); return 0;