From 93f70f900da36fbc19c13c2aa04b2e468c8d00fb Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Fri, 28 May 2010 09:29:20 +0900 Subject: HWPOISON, hugetlb: isolate corrupted hugepage If error hugepage is not in-use, we can fully recovery from error by dequeuing it from freelist, so return RECOVERY. Otherwise whether or not we can recovery depends on user processes, so return DELAYED. Dependency: "HWPOISON, hugetlb: enable error handling path for hugepage" Signed-off-by: Naoya Horiguchi Cc: Andrew Morton Acked-by: Fengguang Wu Signed-off-by: Andi Kleen --- mm/hugetlb.c | 16 ++++++++++++++++ mm/memory-failure.c | 28 ++++++++++++++++++++-------- 2 files changed, 36 insertions(+), 8 deletions(-) (limited to 'mm') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index aa3c51739378..8c163f64cf10 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2825,3 +2825,19 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) hugetlb_put_quota(inode->i_mapping, (chg - freed)); hugetlb_acct_memory(h, -(chg - freed)); } + +/* + * This function is called from memory failure code. + * Assume the caller holds page lock of the head page. + */ +void __isolate_hwpoisoned_huge_page(struct page *hpage) +{ + struct hstate *h = page_hstate(hpage); + int nid = page_to_nid(hpage); + + spin_lock(&hugetlb_lock); + list_del(&hpage->lru); + h->free_huge_pages--; + h->free_huge_pages_node[nid]--; + spin_unlock(&hugetlb_lock); +} diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 473f15a3356d..d0b420aba726 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -690,17 +690,29 @@ static int me_swapcache_clean(struct page *p, unsigned long pfn) /* * Huge pages. Needs work. * Issues: - * No rmap support so we cannot find the original mapper. In theory could walk - * all MMs and look for the mappings, but that would be non atomic and racy. - * Need rmap for hugepages for this. Alternatively we could employ a heuristic, - * like just walking the current process and hoping it has it mapped (that - * should be usually true for the common "shared database cache" case) - * Should handle free huge pages and dequeue them too, but this needs to - * handle huge page accounting correctly. + * - Error on hugepage is contained in hugepage unit (not in raw page unit.) + * To narrow down kill region to one page, we need to break up pmd. + * - To support soft-offlining for hugepage, we need to support hugepage + * migration. */ static int me_huge_page(struct page *p, unsigned long pfn) { - return FAILED; + struct page *hpage = compound_head(p); + /* + * We can safely recover from error on free or reserved (i.e. + * not in-use) hugepage by dequeuing it from freelist. + * To check whether a hugepage is in-use or not, we can't use + * 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))) { + __isolate_hwpoisoned_huge_page(hpage); + return RECOVERED; + } + return DELAYED; } /* -- cgit v1.2.3