From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Subject: 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@xxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Reported-by: Zhan Chen <zhanc1@xxxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 1 - mm/memory-failure.c | 2 -- 2 files changed, 3 deletions(-) diff -puN mm/hugetlb.c~mm-hwpoison-remove-incorrect-comment mm/hugetlb.c --- a/mm/hugetlb.c~mm-hwpoison-remove-incorrect-comment +++ a/mm/hugetlb.c @@ -4391,7 +4391,6 @@ follow_huge_pud(struct mm_struct *mm, un /* * 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 -puN mm/memory-failure.c~mm-hwpoison-remove-incorrect-comment mm/memory-failure.c --- a/mm/memory-failure.c~mm-hwpoison-remove-incorrect-comment +++ a/mm/memory-failure.c @@ -741,8 +741,6 @@ static int me_huge_page(struct page *p, * 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); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
