[PATCH 3/7] HWPOISON, hugetlb: set/clear PG_hwpoison bits on hugepage
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From: Naoya Horiguchi on 13 May 2010 04:00 To avoid race condition between concurrent memory errors on identified hugepage, we atomically test and set PG_hwpoison bit on the head page. All pages in the error hugepage are considered as hwpoisoned for now, so set and clear all PG_hwpoison bits in the hugepage with page lock of the head page held. Dependency: "HWPOISON, hugetlb: enable error handling path for hugepage" Signed-off-by: Naoya Horiguchi <n-horiguchi(a)ah.jp.nec.com> Cc: Andi Kleen <andi(a)firstfloor.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Wu Fengguang <fengguang.wu(a)intel.com> --- mm/memory-failure.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 files changed, 38 insertions(+), 0 deletions(-) diff --git v2.6.34-rc7/mm/memory-failure.c v2.6.34-rc7/mm/memory-failure.c index 1ec68c8..fee648b 100644 --- v2.6.34-rc7/mm/memory-failure.c +++ v2.6.34-rc7/mm/memory-failure.c @@ -920,6 +920,22 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, return ret; } +static void set_page_hwpoison_huge_page(struct page *hpage) +{ + int i; + int nr_pages = 1 << compound_order(hpage); + for (i = 0; i < nr_pages; i++) + SetPageHWPoison(hpage + i); +} + +static void clear_page_hwpoison_huge_page(struct page *hpage) +{ + int i; + int nr_pages = 1 << compound_order(hpage); + for (i = 0; i < nr_pages; i++) + ClearPageHWPoison(hpage + i); +} + int __memory_failure(unsigned long pfn, int trapno, int flags) { struct page_state *ps; @@ -1014,6 +1030,26 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) return 0; } + /* + * For error on the tail page, we should set PG_hwpoison + * on the head page to show that the hugepage is hwpoisoned + */ + if (PageTail(p) && TestSetPageHWPoison(hpage)) { + action_result(pfn, "hugepage already hardware poisoned", + IGNORED); + unlock_page(hpage); + put_page(hpage); + return 0; + } + /* + * Set PG_hwpoison on all pages in an error hugepage, + * because containment is done in hugepage unit for now. + * Since we have done TestSetPageHWPoison() for the head page with + * page lock held, we can safely set PG_hwpoison bits on tail pages. + */ + if (PageHuge(p)) + set_page_hwpoison_huge_page(hpage); + wait_on_page_writeback(p); /* @@ -1118,6 +1154,8 @@ int unpoison_memory(unsigned long pfn) atomic_long_dec(&mce_bad_pages); freeit = 1; } + if (PageHuge(p)) + clear_page_hwpoison_huge_page(page); unlock_page(page); put_page(page); -- 1.7.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |