From 7c7fd82556c61113b6327c9696b347a82b215072 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Thu, 28 Jul 2016 15:48:38 -0700 Subject: [PATCH] mm: hwpoison: remove incorrect comments dequeue_hwpoisoned_huge_page() can be called without page lock hold, so let's remove incorrect comment. The reason why the page lock is not really needed is that dequeue_hwpoisoned_huge_page() checks page_huge_active() inside hugetlb_lock, which allows us to avoid trying to dequeue a hugepage that are just allocated but not linked to active list yet, even without taking page lock. Link: http://lkml.kernel.org/r/20160720092901.GA15995@www9186uo.sakura.ne.jp Signed-off-by: Naoya Horiguchi Reported-by: Zhan Chen Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 1 - mm/memory-failure.c | 2 -- 2 files changed, 3 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index abc1c5fb7222..213ff90903a6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4391,7 +4391,6 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address, /* * This function is called from memory failure code. - * Assume the caller holds page lock of the head page. */ int dequeue_hwpoisoned_huge_page(struct page *hpage) { diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 11de752ccaf5..de88f33519c0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -741,8 +741,6 @@ static int me_huge_page(struct page *p, unsigned long pfn) * page->lru because it can be used in other hugepage operations, * such as __unmap_hugepage_range() and gather_surplus_pages(). * So instead we use page_mapping() and PageAnon(). - * We assume that this function is called with page lock held, - * so there is no race between isolation and mapping/unmapping. */ if (!(page_mapping(hpage) || PageAnon(hpage))) { res = dequeue_hwpoisoned_huge_page(hpage);