From 03dd4cb26d967f9588437b0fc9cc0e8353322bb7 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Fri, 25 Mar 2016 03:53:42 -0300 Subject: Linux-libre 4.5-gnu --- mm/memory-failure.c | 123 ++++++++++++++++++++++++---------------------------- 1 file changed, 57 insertions(+), 66 deletions(-) (limited to 'mm/memory-failure.c') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 750b7893e..ac595e7a3 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -882,15 +882,7 @@ int get_hwpoison_page(struct page *page) { struct page *head = compound_head(page); - if (PageHuge(head)) - return get_page_unless_zero(head); - - /* - * Thp tail page has special refcounting rule (refcount of tail pages - * is stored in ->_mapcount,) so we can't call get_page_unless_zero() - * directly for tail pages. - */ - if (PageTransHuge(head)) { + if (!PageHuge(head) && PageTransHuge(head)) { /* * Non anonymous thp exists only in allocation/free time. We * can't handle such a case correctly, so let's give it up. @@ -902,41 +894,12 @@ int get_hwpoison_page(struct page *page) page_to_pfn(page)); return 0; } - - if (get_page_unless_zero(head)) { - if (PageTail(page)) - get_page(page); - return 1; - } else { - return 0; - } } - return get_page_unless_zero(page); + return get_page_unless_zero(head); } EXPORT_SYMBOL_GPL(get_hwpoison_page); -/** - * put_hwpoison_page() - Put refcount for memory error handling: - * @page: raw error page (hit by memory error) - */ -void put_hwpoison_page(struct page *page) -{ - struct page *head = compound_head(page); - - if (PageHuge(head)) { - put_page(head); - return; - } - - if (PageTransHuge(head)) - if (page != head) - put_page(head); - - put_page(page); -} -EXPORT_SYMBOL_GPL(put_hwpoison_page); - /* * Do all that is necessary to remove user space mappings. Unmap * the pages and send SIGBUS to the processes if the data was dirty. @@ -1149,7 +1112,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags) } if (!PageHuge(p) && PageTransHuge(hpage)) { + lock_page(hpage); if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) { + unlock_page(hpage); if (!PageAnon(hpage)) pr_err("MCE: %#lx: non anonymous thp\n", pfn); else @@ -1159,6 +1124,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags) put_hwpoison_page(p); return -EBUSY; } + unlock_page(hpage); + get_hwpoison_page(p); + put_hwpoison_page(hpage); VM_BUG_ON_PAGE(!page_count(p), p); hpage = compound_head(p); } @@ -1166,7 +1134,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags) /* * We ignore non-LRU pages for good reasons. * - PG_locked is only well defined for LRU pages and a few others - * - to avoid races with __set_page_locked() + * - to avoid races with __SetPageLocked() * - to avoid races with __SetPageSlab*() (and more non-atomic ops) * The check (unnecessarily) ignores LRU pages being isolated and * walked by the page reclaim code, however that's not a big loss. @@ -1716,6 +1684,49 @@ static int __soft_offline_page(struct page *page, int flags) return ret; } +static int soft_offline_in_use_page(struct page *page, int flags) +{ + int ret; + struct page *hpage = compound_head(page); + + if (!PageHuge(page) && PageTransHuge(hpage)) { + lock_page(hpage); + if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) { + unlock_page(hpage); + if (!PageAnon(hpage)) + pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page)); + else + pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page)); + put_hwpoison_page(hpage); + return -EBUSY; + } + unlock_page(hpage); + get_hwpoison_page(page); + put_hwpoison_page(hpage); + } + + if (PageHuge(page)) + ret = soft_offline_huge_page(page, flags); + else + ret = __soft_offline_page(page, flags); + + return ret; +} + +static void soft_offline_free_page(struct page *page) +{ + if (PageHuge(page)) { + struct page *hpage = compound_head(page); + + set_page_hwpoison_huge_page(hpage); + if (!dequeue_hwpoisoned_huge_page(hpage)) + num_poisoned_pages_add(1 << compound_order(hpage)); + } else { + if (!TestSetPageHWPoison(page)) + num_poisoned_pages_inc(); + } +} + /** * soft_offline_page - Soft offline a page. * @page: page to offline @@ -1742,7 +1753,6 @@ int soft_offline_page(struct page *page, int flags) { int ret; unsigned long pfn = page_to_pfn(page); - struct page *hpage = compound_head(page); if (PageHWPoison(page)) { pr_info("soft offline: %#lx page already poisoned\n", pfn); @@ -1750,34 +1760,15 @@ int soft_offline_page(struct page *page, int flags) put_hwpoison_page(page); return -EBUSY; } - if (!PageHuge(page) && PageTransHuge(hpage)) { - if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) { - pr_info("soft offline: %#lx: failed to split THP\n", - pfn); - if (flags & MF_COUNT_INCREASED) - put_hwpoison_page(page); - return -EBUSY; - } - } get_online_mems(); - ret = get_any_page(page, pfn, flags); put_online_mems(); - if (ret > 0) { /* for in-use pages */ - if (PageHuge(page)) - ret = soft_offline_huge_page(page, flags); - else - ret = __soft_offline_page(page, flags); - } else if (ret == 0) { /* for free pages */ - if (PageHuge(page)) { - set_page_hwpoison_huge_page(hpage); - if (!dequeue_hwpoisoned_huge_page(hpage)) - num_poisoned_pages_add(1 << compound_order(hpage)); - } else { - if (!TestSetPageHWPoison(page)) - num_poisoned_pages_inc(); - } - } + + if (ret > 0) + ret = soft_offline_in_use_page(page, flags); + else if (ret == 0) + soft_offline_free_page(page); + return ret; } -- cgit v1.2.3-54-g00ecf