From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Subject: mm: hwpoison: introduce memory_failure_hugetlb() memory_failure() is a big function and hard to maintain. Handling hugetlb- and non-hugetlb- case in a single function is not good, so this patch separates PageHuge() branch into a new function, which saves many PageHuge() check. Link: http://lkml.kernel.org/r/1496305019-5493-7-git-send-email-n-horiguchi@xxxxxxxxxxxxx Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory-failure.c | 134 +++++++++++++++++++++++++----------------- 1 file changed, 82 insertions(+), 52 deletions(-) diff -puN mm/memory-failure.c~mm-hwpoison-introduce-memory_failure_hugetlb mm/memory-failure.c --- a/mm/memory-failure.c~mm-hwpoison-introduce-memory_failure_hugetlb +++ a/mm/memory-failure.c @@ -1009,6 +1009,76 @@ static bool hwpoison_user_mappings(struc return unmap_success; } +static int memory_failure_hugetlb(unsigned long pfn, int trapno, int flags) +{ + struct page_state *ps; + struct page *p = pfn_to_page(pfn); + struct page *head = compound_head(p); + int res; + unsigned long page_flags; + + if (TestSetPageHWPoison(head)) { + pr_err("Memory failure: %#lx: already hardware poisoned\n", + pfn); + return 0; + } + + num_poisoned_pages_inc(); + + if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) { + /* + * Check "filter hit" and "race with other subpage." + */ + lock_page(head); + if (PageHWPoison(head)) { + if ((hwpoison_filter(p) && TestClearPageHWPoison(p)) + || (p != head && TestSetPageHWPoison(head))) { + num_poisoned_pages_dec(); + unlock_page(head); + return 0; + } + } + unlock_page(head); + dissolve_free_huge_page(p); + action_result(pfn, MF_MSG_FREE_HUGE, MF_DELAYED); + return 0; + } + + lock_page(head); + page_flags = head->flags; + + if (!PageHWPoison(head)) { + pr_err("Memory failure: %#lx: just unpoisoned\n", pfn); + num_poisoned_pages_dec(); + unlock_page(head); + put_hwpoison_page(head); + return 0; + } + + if (!hwpoison_user_mappings(p, pfn, trapno, flags, &head)) { + action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); + res = -EBUSY; + goto out; + } + + res = -EBUSY; + + for (ps = error_states;; ps++) + if ((p->flags & ps->mask) == ps->res) + break; + + page_flags |= (p->flags & (1UL << PG_dirty)); + + if (!ps->mask) + for (ps = error_states;; ps++) + if ((page_flags & ps->mask) == ps->res) + break; + res = page_action(ps, p, pfn); +out: + unlock_page(head); + return res; +} + /** * memory_failure - Handle memory failure of a page. * @pfn: Page Number of the corrupted page @@ -1046,33 +1116,22 @@ int memory_failure(unsigned long pfn, in } 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 (PageHuge(p)) + return memory_failure_hugetlb(pfn, trapno, flags); if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); return 0; } -tmp: + orig_head = hpage = compound_head(p); num_poisoned_pages_inc(); /* * 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 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. + * 2) 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. @@ -1083,31 +1142,13 @@ tmp: if (is_free_buddy_page(p)) { action_result(pfn, MF_MSG_BUDDY, MF_DELAYED); return 0; - } else if (PageHuge(hpage)) { - /* - * Check "filter hit" and "race with other subpage." - */ - lock_page(hpage); - if (PageHWPoison(hpage)) { - if ((hwpoison_filter(p) && TestClearPageHWPoison(p)) - || (p != hpage && TestSetPageHWPoison(hpage))) { - num_poisoned_pages_dec(); - unlock_page(hpage); - return 0; - } - } - res = dequeue_hwpoisoned_huge_page(hpage); - action_result(pfn, MF_MSG_FREE_HUGE, - res ? MF_IGNORED : MF_DELAYED); - unlock_page(hpage); - return res; } else { action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); return -EBUSY; } } - if (!PageHuge(p) && PageTransHuge(hpage)) { + if (PageTransHuge(hpage)) { lock_page(p); if (!PageAnon(p) || unlikely(split_huge_page(p))) { unlock_page(p); @@ -1145,7 +1186,7 @@ tmp: return 0; } - lock_page(hpage); + lock_page(p); /* * The page could have changed compound pages during the locking. @@ -1175,33 +1216,22 @@ tmp: if (!PageHWPoison(p)) { pr_err("Memory failure: %#lx: just unpoisoned\n", pfn); num_poisoned_pages_dec(); - unlock_page(hpage); - put_hwpoison_page(hpage); + unlock_page(p); + put_hwpoison_page(p); return 0; } if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) num_poisoned_pages_dec(); - unlock_page(hpage); - put_hwpoison_page(hpage); + unlock_page(p); + put_hwpoison_page(p); return 0; } - if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p)) + if (!PageTransTail(p) && !PageLRU(p)) goto identify_page_state; /* - * For error on the tail page, we should set PG_hwpoison - * on the head page to show that the hugepage is hwpoisoned - */ - if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) { - action_result(pfn, MF_MSG_POISONED_HUGE, MF_IGNORED); - unlock_page(hpage); - put_hwpoison_page(hpage); - return 0; - } - - /* * It's very difficult to mess with pages currently under IO * and in many cases impossible, so we just avoid it here. */ @@ -1248,7 +1278,7 @@ identify_page_state: break; res = page_action(ps, p, pfn); out: - unlock_page(hpage); + unlock_page(p); return res; } EXPORT_SYMBOL_GPL(memory_failure); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
