From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79001C433F5 for ; Fri, 7 Oct 2022 01:08:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232454AbiJGBIH (ORCPT ); Thu, 6 Oct 2022 21:08:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230227AbiJGBIF (ORCPT ); Thu, 6 Oct 2022 21:08:05 -0400 Received: from out2.migadu.com (out2.migadu.com [IPv6:2001:41d0:2:aacc::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2DFF54CAA for ; Thu, 6 Oct 2022 18:08:03 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1665104882; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=krAD9xLJSfd65WNvNS9948vrC1J/iarhYMZsja8cZPU=; b=lok6PnIhq678tprMIqA2vTYMFryk8l8T5ke+eO9B0EUyDrpDzi4FTgjhozdl2uTv5NK40d me4jAoSqGsEIaGCrCNmu+d21ZF9+by7M4WJF/CzYCJImitXtP0AZo2Qr+9eVGeX6nUHp7K sEt9U6M1w8AaATUe53eGhRtrwus7Lyw= From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , Miaohe Lin , David Hildenbrand , Mike Kravetz , Yang Shi , Oscar Salvador , Muchun Song , Jane Chu , Naoya Horiguchi , linux-kernel@vger.kernel.org Subject: [PATCH v6 1/4] mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage Date: Fri, 7 Oct 2022 10:07:03 +0900 Message-Id: <20221007010706.2916472-2-naoya.horiguchi@linux.dev> In-Reply-To: <20221007010706.2916472-1-naoya.horiguchi@linux.dev> References: <20221007010706.2916472-1-naoya.horiguchi@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Naoya Horiguchi HWPoisoned page is not supposed to be accessed once marked, but currently such accesses can happen during memory hotremove because do_migrate_range() can be called before dissolve_free_huge_pages() is called. Clear HPageMigratable for hwpoisoned hugepages to prevent them from being migrated. This should be done in hugetlb_lock to avoid race against isolate_hugetlb(). get_hwpoison_huge_page() needs to have a flag to show it's called from unpoison to take refcount of hwpoisoned hugepages, so add it. Reported-by: Miaohe Lin Signed-off-by: Naoya Horiguchi --- ChangeLog v3 -> v6: - introduce migratable_cleared to remember that HPageMigratable is cleared in error handling. It's needed to cancel when an error event is filtered by hwpoison_filter(). (Thanks to Miaohe) ChangeLog v2 -> v3 - move to the approach of clearing HPageMigratable instead of shifting dissolve_free_huge_pages. --- include/linux/hugetlb.h | 10 ++++++---- include/linux/mm.h | 6 ++++-- mm/hugetlb.c | 9 +++++---- mm/memory-failure.c | 21 +++++++++++++++++---- 4 files changed, 32 insertions(+), 14 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 32d45e96a894..19b99ff7fea0 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -183,8 +183,9 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to, long hugetlb_unreserve_pages(struct inode *inode, long start, long end, long freed); int isolate_hugetlb(struct page *page, struct list_head *list); -int get_hwpoison_huge_page(struct page *page, bool *hugetlb); -int get_huge_page_for_hwpoison(unsigned long pfn, int flags); +int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison); +int get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared); void putback_active_hugepage(struct page *page); void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason); void free_huge_page(struct page *page); @@ -391,12 +392,13 @@ static inline int isolate_hugetlb(struct page *page, struct list_head *list) return -EBUSY; } -static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb) +static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison) { return 0; } -static inline int get_huge_page_for_hwpoison(unsigned long pfn, int flags) +static inline int get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { return 0; } diff --git a/include/linux/mm.h b/include/linux/mm.h index 8bbcccbc5565..3264bf993ad8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3277,9 +3277,11 @@ extern void shake_page(struct page *p); extern atomic_long_t num_poisoned_pages __read_mostly; extern int soft_offline_page(unsigned long pfn, int flags); #ifdef CONFIG_MEMORY_FAILURE -extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags); +extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared); #else -static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) +static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { return 0; } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 63fe47a0240a..0e482dfaf92e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7253,7 +7253,7 @@ int isolate_hugetlb(struct page *page, struct list_head *list) return ret; } -int get_hwpoison_huge_page(struct page *page, bool *hugetlb) +int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison) { int ret = 0; @@ -7263,7 +7263,7 @@ int get_hwpoison_huge_page(struct page *page, bool *hugetlb) *hugetlb = true; if (HPageFreed(page)) ret = 0; - else if (HPageMigratable(page)) + else if (HPageMigratable(page) || unpoison) ret = get_page_unless_zero(page); else ret = -EBUSY; @@ -7272,12 +7272,13 @@ int get_hwpoison_huge_page(struct page *page, bool *hugetlb) return ret; } -int get_huge_page_for_hwpoison(unsigned long pfn, int flags) +int get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { int ret; spin_lock_irq(&hugetlb_lock); - ret = __get_huge_page_for_hwpoison(pfn, flags); + ret = __get_huge_page_for_hwpoison(pfn, flags, migratable_cleared); spin_unlock_irq(&hugetlb_lock); return ret; } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 145bb561ddb3..d4fef56c0438 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1244,7 +1244,7 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) int ret = 0; bool hugetlb = false; - ret = get_hwpoison_huge_page(head, &hugetlb); + ret = get_hwpoison_huge_page(head, &hugetlb, false); if (hugetlb) return ret; @@ -1334,7 +1334,7 @@ static int __get_unpoison_page(struct page *page) int ret = 0; bool hugetlb = false; - ret = get_hwpoison_huge_page(head, &hugetlb); + ret = get_hwpoison_huge_page(head, &hugetlb, true); if (hugetlb) return ret; @@ -1785,7 +1785,8 @@ void hugetlb_clear_page_hwpoison(struct page *hpage) * -EBUSY - the hugepage is busy (try to retry) * -EHWPOISON - the hugepage is already hwpoisoned */ -int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) +int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, + bool *migratable_cleared) { struct page *page = pfn_to_page(pfn); struct page *head = compound_head(page); @@ -1815,6 +1816,15 @@ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) goto out; } + /* + * Clearing HPageMigratable for hwpoisoned hugepages to prevent them + * from being migrated by memory hotremove. + */ + if (count_increased) { + *migratable_cleared = true; + ClearHPageMigratable(head); + } + return ret; out: if (count_increased) @@ -1834,10 +1844,11 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb struct page *p = pfn_to_page(pfn); struct page *head; unsigned long page_flags; + bool migratable_cleared = false; *hugetlb = 1; retry: - res = get_huge_page_for_hwpoison(pfn, flags); + res = get_huge_page_for_hwpoison(pfn, flags, &migratable_cleared); if (res == 2) { /* fallback to normal page handling */ *hugetlb = 0; return 0; @@ -1862,6 +1873,8 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb if (hwpoison_filter(p)) { hugetlb_clear_page_hwpoison(head); + if (migratable_cleared) + SetHPageMigratable(head); unlock_page(head); if (res == 1) put_page(head); -- 2.25.1