diff options
| -rw-r--r-- | mm/madvise.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index ed137fde4459..98e28e777ccb 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -270,6 +270,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, spinlock_t *ptl; pte_t *orig_pte, *pte, ptent; struct page *page; + int nr_swap = 0; split_huge_pmd(vma, pmd, addr); if (pmd_trans_unstable(pmd)) @@ -280,8 +281,24 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, for (; addr != end; pte++, addr += PAGE_SIZE) { ptent = *pte; - if (!pte_present(ptent)) + if (pte_none(ptent)) continue; + /* + * If the pte has swp_entry, just clear page table to + * prevent swap-in which is more expensive rather than + * (page allocation + zeroing). + */ + if (!pte_present(ptent)) { + swp_entry_t entry; + + entry = pte_to_swp_entry(ptent); + if (non_swap_entry(entry)) + continue; + nr_swap--; + free_swap_and_cache(entry); + pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); + continue; + } page = vm_normal_page(vma, addr, ptent); if (!page) @@ -355,6 +372,12 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, } } out: + if (nr_swap) { + if (current->mm == mm) + sync_mm_rss(mm); + + add_mm_counter(mm, MM_SWAPENTS, nr_swap); + } arch_leave_lazy_mmu_mode(); pte_unmap_unlock(orig_pte, ptl); cond_resched(); |