From 699fa216808fff47efc9743f92f1b8a9f9bf5321 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 24 Feb 2017 14:57:51 -0800 Subject: [PATCH] mm: fix handling PTE-mapped THPs in page_idle_clear_pte_refs() For PTE-mapped THP page_check_address_transhuge() is not adequate: it cannot find all relevant PTEs, only the first one.i Let's switch it to page_vma_mapped_walk(). I don't think it's subject for stable@: it's not fatal. Link: http://lkml.kernel.org/r/20170129173858.45174-5-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Cc: Vladimir Davydov Cc: Andrea Arcangeli Cc: Hillf Danton Cc: Hugh Dickins Cc: Johannes Weiner Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Srikar Dronamraju Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_idle.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/mm/page_idle.c b/mm/page_idle.c index ae11aa9..b0ee56c 100644 --- a/mm/page_idle.c +++ b/mm/page_idle.c @@ -54,27 +54,27 @@ static int page_idle_clear_pte_refs_one(struct page *page, struct vm_area_struct *vma, unsigned long addr, void *arg) { - struct mm_struct *mm = vma->vm_mm; - pmd_t *pmd; - pte_t *pte; - spinlock_t *ptl; + struct page_vma_mapped_walk pvmw = { + .page = page, + .vma = vma, + .address = addr, + }; bool referenced = false; - if (!page_check_address_transhuge(page, mm, addr, &pmd, &pte, &ptl)) - return SWAP_AGAIN; - - if (pte) { - referenced = ptep_clear_young_notify(vma, addr, pte); - pte_unmap(pte); - } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { - referenced = pmdp_clear_young_notify(vma, addr, pmd); - } else { - /* unexpected pmd-mapped page? */ - WARN_ON_ONCE(1); + while (page_vma_mapped_walk(&pvmw)) { + addr = pvmw.address; + if (pvmw.pte) { + referenced = ptep_clear_young_notify(vma, addr, + pvmw.pte); + } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { + referenced = pmdp_clear_young_notify(vma, addr, + pvmw.pmd); + } else { + /* unexpected pmd-mapped page? */ + WARN_ON_ONCE(1); + } } - spin_unlock(ptl); - if (referenced) { clear_page_idle(page); /* -- 2.7.4