From 07443a85ad90c7b62fbe11dcd3d6a1de1e10516f Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Wed, 11 Sep 2013 14:21:58 -0700 Subject: mm, hugetlb: return a reserved page to a reserved pool if failed If we fail with a reserved page, just calling put_page() is not sufficient, because put_page() invoke free_huge_page() at last step and it doesn't know whether a page comes from a reserved pool or not. So it doesn't do anything related to reserved count. This makes reserve count lower than how we need, because reserve count already decrease in dequeue_huge_page_vma(). This patch fix this situation. Signed-off-by: Joonsoo Kim Cc: Aneesh Kumar Cc: Naoya Horiguchi Cc: Davidlohr Bueso Cc: David Gibson Cc: Wanpeng Li Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5bf6468a8862..06315560bd23 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -572,6 +572,7 @@ retry_cpuset: if (!vma_has_reserves(vma, chg)) break; + SetPagePrivate(page); h->resv_huge_pages--; break; } @@ -629,15 +630,20 @@ static void free_huge_page(struct page *page) int nid = page_to_nid(page); struct hugepage_subpool *spool = (struct hugepage_subpool *)page_private(page); + bool restore_reserve; set_page_private(page, 0); page->mapping = NULL; BUG_ON(page_count(page)); BUG_ON(page_mapcount(page)); + restore_reserve = PagePrivate(page); spin_lock(&hugetlb_lock); hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h), page); + if (restore_reserve) + h->resv_huge_pages++; + if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { /* remove the page from active list */ list_del(&page->lru); @@ -2636,6 +2642,8 @@ retry_avoidcopy: spin_lock(&mm->page_table_lock); ptep = huge_pte_offset(mm, address & huge_page_mask(h)); if (likely(pte_same(huge_ptep_get(ptep), pte))) { + ClearPagePrivate(new_page); + /* Break COW */ huge_ptep_clear_flush(vma, address, ptep); set_huge_pte_at(mm, address, ptep, @@ -2747,6 +2755,7 @@ retry: goto retry; goto out; } + ClearPagePrivate(page); spin_lock(&inode->i_lock); inode->i_blocks += blocks_per_huge_page(h); @@ -2793,8 +2802,10 @@ retry: if (!huge_pte_none(huge_ptep_get(ptep))) goto backout; - if (anon_rmap) + if (anon_rmap) { + ClearPagePrivate(page); hugepage_add_new_anon_rmap(page, vma, address); + } else page_dup_rmap(page); new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) -- cgit v1.2.3