From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id C40DB6B0098 for ; Tue, 9 Mar 2010 14:44:21 -0500 (EST) Message-Id: <20100309194316.650729518@redhat.com> Date: Tue, 09 Mar 2010 20:39:32 +0100 From: aarcange@redhat.com Subject: [patch 31/35] pmd_trans_huge migrate bugcheck References: <20100309193901.207868642@redhat.com> Content-Disposition: inline; filename=pmd_trans_huge_migrate Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: Marcelo Tosatti , Adam Litke , Avi Kivity , Izik Eidus , Hugh Dickins , Nick Piggin , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , Arnd Bergmann , "Michael S. Tsirkin" , Peter Zijlstra , Andrea Arcangeli List-ID: From: Andrea Arcangeli No pmd_trans_huge should ever materialize in migration ptes areas, because we split the hugepage before migration ptes are instantiated. Signed-off-by: Andrea Arcangeli Acked-by: Rik van Riel --- include/linux/huge_mm.h | 5 +++++ mm/migrate.c | 5 +++++ 2 files changed, 10 insertions(+) --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -113,6 +113,10 @@ static inline int PageTransHuge(struct p VM_BUG_ON(PageTail(page)); return PageHead(page); } +static inline int PageTransCompound(struct page *page) +{ + return PageCompound(page); +} #else /* CONFIG_TRANSPARENT_HUGEPAGE */ #define HPAGE_PMD_SHIFT ({ BUG(); 0; }) #define HPAGE_PMD_MASK ({ BUG(); 0; }) @@ -132,6 +136,7 @@ static inline int split_huge_page(struct #define wait_split_huge_page(__anon_vma, __pmd) \ do { } while (0) #define PageTransHuge(page) 0 +#define PageTransCompound(page) 0 static inline int hugepage_madvise(unsigned long *vm_flags) { BUG_ON(0); --- a/mm/migrate.c +++ b/mm/migrate.c @@ -99,6 +99,7 @@ static int remove_migration_pte(struct p goto out; pmd = pmd_offset(pud, addr); + VM_BUG_ON(pmd_trans_huge(*pmd)); if (!pmd_present(*pmd)) goto out; @@ -815,6 +816,10 @@ static int do_move_page_to_node_array(st if (PageReserved(page) || PageKsm(page)) goto put_and_set; + if (unlikely(PageTransCompound(page))) + if (unlikely(split_huge_page(page))) + goto put_and_set; + pp->page = page; err = page_to_nid(page); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org