diff options
Diffstat (limited to 'mm/memory-failure.c')
| -rw-r--r-- | mm/memory-failure.c | 102 |
1 files changed, 93 insertions, 9 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2044fe8920c2..44a8cefeae6e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -697,11 +697,10 @@ static int me_swapcache_clean(struct page *p, unsigned long pfn) * Issues: * - 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) { + int res = 0; struct page *hpage = compound_head(p); /* * We can safely recover from error on free or reserved (i.e. @@ -714,8 +713,9 @@ static int me_huge_page(struct page *p, unsigned long pfn) * so there is no race between isolation and mapping/unmapping. */ if (!(page_mapping(hpage) || PageAnon(hpage))) { - __isolate_hwpoisoned_huge_page(hpage); - return RECOVERED; + res = dequeue_hwpoisoned_huge_page(hpage); + if (!res) + return RECOVERED; } return DELAYED; } @@ -972,7 +972,10 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * We need/can do nothing about count=0 pages. * 1) it's a free page, and therefore in safe hand: * prep_new_page() will be the gate keeper. - * 2) it's part of a non-compound high order page. + * 2) it's a free hugepage, which is also safe: + * an affected hugepage will be dequeued from hugepage freelist, + * so there's no concern about reusing it ever after. + * 3) it's part of a non-compound high order page. * Implies some kernel user: cannot stop them from * R/W the page; let's pray that the page has been * used and will be freed some time later. @@ -984,6 +987,24 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) if (is_free_buddy_page(p)) { action_result(pfn, "free buddy", DELAYED); return 0; + } else if (PageHuge(hpage)) { + /* + * Check "just unpoisoned", "filter hit", and + * "race with other subpage." + */ + lock_page_nosync(hpage); + if (!PageHWPoison(hpage) + || (hwpoison_filter(p) && TestClearPageHWPoison(p)) + || (p != hpage && TestSetPageHWPoison(hpage))) { + atomic_long_sub(nr_pages, &mce_bad_pages); + return 0; + } + set_page_hwpoison_huge_page(hpage); + res = dequeue_hwpoisoned_huge_page(hpage); + action_result(pfn, "free huge", + res ? IGNORED : DELAYED); + unlock_page(hpage); + return res; } else { action_result(pfn, "high order kernel", IGNORED); return -EBUSY; @@ -1145,6 +1166,16 @@ int unpoison_memory(unsigned long pfn) nr_pages = 1 << compound_order(page); if (!get_page_unless_zero(page)) { + /* + * Since HWPoisoned hugepage should have non-zero refcount, + * race between memory failure and unpoison seems to happen. + * In such case unpoison fails and memory failure runs + * to the end. + */ + if (PageHuge(page)) { + pr_debug("MCE: Memory failure is now running on free hugepage %#lx\n", pfn); + return 0; + } if (TestClearPageHWPoison(p)) atomic_long_sub(nr_pages, &mce_bad_pages); pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn); @@ -1162,9 +1193,9 @@ int unpoison_memory(unsigned long pfn) pr_info("MCE: Software-unpoisoned page %#lx\n", pfn); atomic_long_sub(nr_pages, &mce_bad_pages); freeit = 1; + if (PageHuge(page)) + clear_page_hwpoison_huge_page(page); } - if (PageHuge(p)) - clear_page_hwpoison_huge_page(page); unlock_page(page); put_page(page); @@ -1178,7 +1209,11 @@ EXPORT_SYMBOL(unpoison_memory); static struct page *new_page(struct page *p, unsigned long private, int **x) { int nid = page_to_nid(p); - return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0); + if (PageHuge(p)) + return alloc_huge_page_node(page_hstate(compound_head(p)), + nid); + else + return alloc_pages_exact_node(nid, GFP_HIGHUSER_MOVABLE, 0); } /* @@ -1206,8 +1241,15 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) * was free. */ set_migratetype_isolate(p); + /* + * When the target page is a free hugepage, just remove it + * from free hugepage list. + */ if (!get_page_unless_zero(compound_head(p))) { - if (is_free_buddy_page(p)) { + if (PageHuge(p)) { + pr_info("get_any_page: %#lx free huge page\n", pfn); + ret = dequeue_hwpoisoned_huge_page(compound_head(p)); + } else if (is_free_buddy_page(p)) { pr_info("get_any_page: %#lx free buddy page\n", pfn); /* Set hwpoison bit while page is still isolated */ SetPageHWPoison(p); @@ -1226,6 +1268,45 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) return ret; } +static int soft_offline_huge_page(struct page *page, int flags) +{ + int ret; + unsigned long pfn = page_to_pfn(page); + struct page *hpage = compound_head(page); + LIST_HEAD(pagelist); + + ret = get_any_page(page, pfn, flags); + if (ret < 0) + return ret; + if (ret == 0) + goto done; + + if (PageHWPoison(hpage)) { + put_page(hpage); + pr_debug("soft offline: %#lx hugepage already poisoned\n", pfn); + return -EBUSY; + } + + /* Keep page count to indicate a given hugepage is isolated. */ + + list_add(&hpage->lru, &pagelist); + ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0); + if (ret) { + pr_debug("soft offline: %#lx: migration failed %d, type %lx\n", + pfn, ret, page->flags); + if (ret > 0) + ret = -EIO; + return ret; + } +done: + if (!PageHWPoison(hpage)) + atomic_long_add(1 << compound_order(hpage), &mce_bad_pages); + set_page_hwpoison_huge_page(hpage); + dequeue_hwpoisoned_huge_page(hpage); + /* keep elevated page count for bad page */ + return ret; +} + /** * soft_offline_page - Soft offline a page. * @page: page to offline @@ -1253,6 +1334,9 @@ int soft_offline_page(struct page *page, int flags) int ret; unsigned long pfn = page_to_pfn(page); + if (PageHuge(page)) + return soft_offline_huge_page(page, flags); + ret = get_any_page(page, pfn, flags); if (ret < 0) return ret; |