Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751707AbdFAISd (ORCPT ); Thu, 1 Jun 2017 04:18:33 -0400 Received: from mail-io0-f196.google.com ([209.85.223.196]:34554 "EHLO mail-io0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495AbdFAIRS (ORCPT ); Thu, 1 Jun 2017 04:17:18 -0400 From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , Michal Hocko , "Aneesh Kumar K.V" , Anshuman Khandual , linux-kernel@vger.kernel.org, Naoya Horiguchi Subject: [PATCH v1 3/9] mm: hwpoison: change PageHWPoison behavior on hugetlb pages Date: Thu, 1 Jun 2017 17:16:53 +0900 Message-Id: <1496305019-5493-4-git-send-email-n-horiguchi@ah.jp.nec.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1496305019-5493-1-git-send-email-n-horiguchi@ah.jp.nec.com> References: <1496305019-5493-1-git-send-email-n-horiguchi@ah.jp.nec.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7178 Lines: 231 We'd like to narrow down the error region in memory error on hugetlb pages. However, currently we set PageHWPoison flags on all subpages in the error hugepage and add # of subpages to num_hwpoison_pages, which doesn't fit our purpose. So this patch changes the behavior and we only set PageHWPoison on the head page then increase num_hwpoison_pages only by 1. This is a preparation for narrow-down part which comes in later patches. Signed-off-by: Naoya Horiguchi --- include/linux/swapops.h | 9 ----- mm/memory-failure.c | 87 ++++++++++++++----------------------------------- 2 files changed, 24 insertions(+), 72 deletions(-) diff --git v4.12-rc3/include/linux/swapops.h v4.12-rc3_patched/include/linux/swapops.h index 5c3a5f3..c5ff7b2 100644 --- v4.12-rc3/include/linux/swapops.h +++ v4.12-rc3_patched/include/linux/swapops.h @@ -196,15 +196,6 @@ static inline void num_poisoned_pages_dec(void) atomic_long_dec(&num_poisoned_pages); } -static inline void num_poisoned_pages_add(long num) -{ - atomic_long_add(num, &num_poisoned_pages); -} - -static inline void num_poisoned_pages_sub(long num) -{ - atomic_long_sub(num, &num_poisoned_pages); -} #else static inline swp_entry_t make_hwpoison_entry(struct page *page) diff --git v4.12-rc3/mm/memory-failure.c v4.12-rc3_patched/mm/memory-failure.c index 6c1a7c9..aae620f 100644 --- v4.12-rc3/mm/memory-failure.c +++ v4.12-rc3_patched/mm/memory-failure.c @@ -1009,22 +1009,6 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, return unmap_success; } -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); -} - /** * memory_failure - Handle memory failure of a page. * @pfn: Page Number of the corrupted page @@ -1050,7 +1034,6 @@ int memory_failure(unsigned long pfn, int trapno, int flags) struct page *hpage; struct page *orig_head; int res; - unsigned int nr_pages; unsigned long page_flags; if (!sysctl_memory_failure_recovery) @@ -1064,24 +1047,23 @@ int memory_failure(unsigned long pfn, int trapno, int flags) p = pfn_to_page(pfn); orig_head = hpage = compound_head(p); + + /* tmporary check code, to be updated in later patches */ + if (PageHuge(p)) { + if (TestSetPageHWPoison(hpage)) { + pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); + return 0; + } + goto tmp; + } if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); return 0; } - /* - * Currently errors on hugetlbfs pages are measured in hugepage units, - * so nr_pages should be 1 << compound_order. OTOH when errors are on - * transparent hugepages, they are supposed to be split and error - * measurement is done in normal page units. So nr_pages should be one - * in this case. - */ - if (PageHuge(p)) - nr_pages = 1 << compound_order(hpage); - else /* normal page or thp */ - nr_pages = 1; - num_poisoned_pages_add(nr_pages); +tmp: + num_poisoned_pages_inc(); /* * We need/can do nothing about count=0 pages. @@ -1109,12 +1091,11 @@ int memory_failure(unsigned long pfn, int trapno, int flags) if (PageHWPoison(hpage)) { if ((hwpoison_filter(p) && TestClearPageHWPoison(p)) || (p != hpage && TestSetPageHWPoison(hpage))) { - num_poisoned_pages_sub(nr_pages); + num_poisoned_pages_dec(); unlock_page(hpage); return 0; } } - set_page_hwpoison_huge_page(hpage); res = dequeue_hwpoisoned_huge_page(hpage); action_result(pfn, MF_MSG_FREE_HUGE, res ? MF_IGNORED : MF_DELAYED); @@ -1137,7 +1118,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags) pr_err("Memory failure: %#lx: thp split failed\n", pfn); if (TestClearPageHWPoison(p)) - num_poisoned_pages_sub(nr_pages); + num_poisoned_pages_dec(); put_hwpoison_page(p); return -EBUSY; } @@ -1190,14 +1171,14 @@ int memory_failure(unsigned long pfn, int trapno, int flags) */ if (!PageHWPoison(p)) { pr_err("Memory failure: %#lx: just unpoisoned\n", pfn); - num_poisoned_pages_sub(nr_pages); + num_poisoned_pages_dec(); unlock_page(hpage); put_hwpoison_page(hpage); return 0; } if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) - num_poisoned_pages_sub(nr_pages); + num_poisoned_pages_dec(); unlock_page(hpage); put_hwpoison_page(hpage); return 0; @@ -1216,14 +1197,6 @@ int memory_failure(unsigned long pfn, int trapno, int flags) put_hwpoison_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); /* * It's very difficult to mess with pages currently under IO @@ -1394,7 +1367,6 @@ int unpoison_memory(unsigned long pfn) struct page *page; struct page *p; int freeit = 0; - unsigned int nr_pages; static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); @@ -1439,8 +1411,6 @@ int unpoison_memory(unsigned long pfn) return 0; } - nr_pages = 1 << compound_order(page); - if (!get_hwpoison_page(p)) { /* * Since HWPoisoned hugepage should have non-zero refcount, @@ -1470,10 +1440,8 @@ int unpoison_memory(unsigned long pfn) if (TestClearPageHWPoison(page)) { unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n", pfn, &unpoison_rs); - num_poisoned_pages_sub(nr_pages); + num_poisoned_pages_dec(); freeit = 1; - if (PageHuge(page)) - clear_page_hwpoison_huge_page(page); } unlock_page(page); @@ -1604,14 +1572,10 @@ static int soft_offline_huge_page(struct page *page, int flags) ret = -EIO; } else { /* overcommit hugetlb page will be freed to buddy */ - if (PageHuge(page)) { - set_page_hwpoison_huge_page(hpage); + SetPageHWPoison(page); + if (PageHuge(page)) dequeue_hwpoisoned_huge_page(hpage); - num_poisoned_pages_add(1 << compound_order(hpage)); - } else { - SetPageHWPoison(page); - num_poisoned_pages_inc(); - } + num_poisoned_pages_inc(); } return ret; } @@ -1727,15 +1691,12 @@ static int soft_offline_in_use_page(struct page *page, int flags) static void soft_offline_free_page(struct page *page) { - if (PageHuge(page)) { - struct page *hpage = compound_head(page); + struct page *head = 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(); + if (!TestSetPageHWPoison(head)) { + num_poisoned_pages_inc(); + if (PageHuge(head)) + dequeue_hwpoisoned_huge_page(head); } } -- 2.7.0