From nobody Mon Feb 9 06:24:27 2026 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 B6A48EB64D9 for ; Fri, 7 Jul 2023 20:19:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232808AbjGGUT3 (ORCPT ); Fri, 7 Jul 2023 16:19:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232770AbjGGUTW (ORCPT ); Fri, 7 Jul 2023 16:19:22 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38DB52126 for ; Fri, 7 Jul 2023 13:19:18 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id 41be03b00d2f7-55b2c66d713so3346115a12.2 for ; Fri, 07 Jul 2023 13:19:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1688761158; x=1691353158; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=lhHFjAXtuMYeiDPTb9enUa1sagPmUht2lF56qHA5nAY=; b=Lm821Q9A8z9/jwUhSfYSBmBg3a1CJgB8uC9S29RR8iamr7rpAYSfO0Eeq787JeWICj aSBaqXte1TU+6+8Sh0EwU0DomQ2dskj2yaXJhdXbMBNjJ8QUuqx8PFueYsGG0LTCGMQM AG5oIBFVs6KD00JEaeesIKk4hiB7jSUeRJ5U9ZVeA4Xg20DZQrowBV2mwu3oDdpyaXg2 VSPJ+oq7NOFgZNlDG3dULstPjbk7FgX8TBv4efKwHSj4dG2SHkzR24FKkM89NmGdxa+V ORZx2FMfNdL9uzR1qedaRjJLe7tuSJorO9cCwuwQmen2ZaI5XXih1iy8y9odfFxhoErc 4nvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688761158; x=1691353158; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=lhHFjAXtuMYeiDPTb9enUa1sagPmUht2lF56qHA5nAY=; b=OQtSlw81L/X+Cft54edpqtYZzn3QBJ3yuyRk/rQ2bjQdEkJDi9UMNOX727vcZ6nkIE eptZ2Pz77edVoNmPdJNp4C6nytOp8ejqofkCtajlVTF2STMm+HgGW4gVIRVA5KQYeZQt s1akhcl3olJvd0Ccfz2UoRTbmaNbjMsJ2j9Lpap0NUQVW3vD422rne0ulZ5Z5QaqN7Cg chJpFAt5HebKq/otse+w2ChXO2KhQ7UZxj6kX20nCgIwbzkgFbC7fE1+ICCdcAQd6fI0 WBAQAdJfsK4rmp6SZsnlYfzd+9YHdaji20DPasvd/5gNG+iuqFN3+/Psj2rjHIIi+cwE zTAA== X-Gm-Message-State: ABy/qLbAIIN9DN0JLZr1iaXm+jDS8Q53DSvRP4bymIRoQIT9X/N/9jze Tl1aZGnkyR+IGbxRS2zxYPcSzIWYLHOKSA== X-Google-Smtp-Source: APBJJlFoY61HjNHb0rFEYpqM/xY1hMlpJ1lQz10syaUR+Qp6bGufuof79IX3dfbrgyCAU0fML5WpoZTLRKI8TQ== X-Received: from yjq3.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:272f]) (user=jiaqiyan job=sendgmr) by 2002:a63:7f51:0:b0:557:5649:381 with SMTP id p17-20020a637f51000000b0055756490381mr4012081pgn.3.1688761157717; Fri, 07 Jul 2023 13:19:17 -0700 (PDT) Date: Fri, 7 Jul 2023 20:19:02 +0000 In-Reply-To: <20230707201904.953262-1-jiaqiyan@google.com> Mime-Version: 1.0 References: <20230707201904.953262-1-jiaqiyan@google.com> X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230707201904.953262-3-jiaqiyan@google.com> Subject: [PATCH v3 2/4] mm/hwpoison: check if a subpage of a hugetlb folio is raw HWPOISON From: Jiaqi Yan To: akpm@linux-foundation.org, mike.kravetz@oracle.com, naoya.horiguchi@nec.com Cc: songmuchun@bytedance.com, shy828301@gmail.com, linmiaohe@huawei.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, duenwen@google.com, axelrasmussen@google.com, jthoughton@google.com, Jiaqi Yan Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add the functionality, is_raw_hwp_subpage, to tell if a subpage of a hugetlb folio is a raw HWPOISON page. This functionality relies on RawHwpUnreliable to be not set; otherwise hugepage's raw HWPOISON list becomes meaningless. is_raw_hwp_subpage needs to hold hugetlb_lock in order to synchronize with __get_huge_page_for_hwpoison, who iterates and inserts an entry to raw_hwp_list. llist itself doesn't ensure insertion is synchornized with the iterating used by __is_raw_hwp_list. Caller can minimize the overhead of lock cycles by first checking if folio / head page's HWPOISON flag is set. Exports this functionality to be immediately used in the read operation for hugetlbfs. Reviewed-by: Mike Kravetz Reviewed-by: Naoya Horiguchi Signed-off-by: Jiaqi Yan --- include/linux/hugetlb.h | 19 +++++++++++++++++++ include/linux/mm.h | 7 +++++++ mm/hugetlb.c | 10 ++++++++++ mm/memory-failure.c | 34 ++++++++++++++++++++++++---------- 4 files changed, 60 insertions(+), 10 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index ca3c8e10f24a..4a745af98525 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -1007,6 +1007,25 @@ void hugetlb_register_node(struct node *node); void hugetlb_unregister_node(struct node *node); #endif =20 +/* + * Struct raw_hwp_page represents information about "raw error page", + * constructing singly linked list from ->_hugetlb_hwpoison field of folio. + */ +struct raw_hwp_page { + struct llist_node node; + struct page *page; +}; + +static inline struct llist_head *raw_hwp_list_head(struct folio *folio) +{ + return (struct llist_head *)&folio->_hugetlb_hwpoison; +} + +/* + * Check if a given raw @subpage in a hugepage @folio is HWPOISON. + */ +bool is_raw_hwp_subpage(struct folio *folio, struct page *subpage); + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; =20 diff --git a/include/linux/mm.h b/include/linux/mm.h index 74f1be743ba2..edaa18b6f731 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3680,6 +3680,7 @@ extern const struct attribute_group memory_failure_at= tr_group; extern void memory_failure_queue(unsigned long pfn, int flags); extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, bool *migratable_cleared); +extern bool __is_raw_hwp_subpage(struct folio *folio, struct page *subpage= ); void num_poisoned_pages_inc(unsigned long pfn); void num_poisoned_pages_sub(unsigned long pfn, long i); struct task_struct *task_early_kill(struct task_struct *tsk, int force_ear= ly); @@ -3694,6 +3695,12 @@ static inline int __get_huge_page_for_hwpoison(unsig= ned long pfn, int flags, return 0; } =20 +static inline bool __is_raw_hwp_subpage(struct folio *folio, + struct page *subpage) +{ + return false; +} + static inline void num_poisoned_pages_inc(unsigned long pfn) { } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index bce28cca73a1..9c608d2f6630 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7373,6 +7373,16 @@ int get_huge_page_for_hwpoison(unsigned long pfn, in= t flags, return ret; } =20 +bool is_raw_hwp_subpage(struct folio *folio, struct page *subpage) +{ + bool ret; + + spin_lock_irq(&hugetlb_lock); + ret =3D __is_raw_hwp_subpage(folio, subpage); + spin_unlock_irq(&hugetlb_lock); + return ret; +} + void folio_putback_active_hugetlb(struct folio *folio) { spin_lock_irq(&hugetlb_lock); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index a08677dcf953..5b6c8ceb13c0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1813,18 +1813,32 @@ EXPORT_SYMBOL_GPL(mf_dax_kill_procs); #endif /* CONFIG_FS_DAX */ =20 #ifdef CONFIG_HUGETLB_PAGE -/* - * Struct raw_hwp_page represents information about "raw error page", - * constructing singly linked list from ->_hugetlb_hwpoison field of folio. - */ -struct raw_hwp_page { - struct llist_node node; - struct page *page; -}; =20 -static inline struct llist_head *raw_hwp_list_head(struct folio *folio) +bool __is_raw_hwp_subpage(struct folio *folio, struct page *subpage) { - return (struct llist_head *)&folio->_hugetlb_hwpoison; + struct llist_head *raw_hwp_head; + struct raw_hwp_page *p, *tmp; + bool ret =3D false; + + if (!folio_test_hwpoison(folio)) + return false; + + /* + * When RawHwpUnreliable is set, kernel lost track of which subpages + * are HWPOISON. So return as if ALL subpages are HWPOISONed. + */ + if (folio_test_hugetlb_raw_hwp_unreliable(folio)) + return true; + + raw_hwp_head =3D raw_hwp_list_head(folio); + llist_for_each_entry_safe(p, tmp, raw_hwp_head->first, node) { + if (subpage =3D=3D p->page) { + ret =3D true; + break; + } + } + + return ret; } =20 static unsigned long __folio_free_raw_hwp(struct folio *folio, bool move_f= lag) --=20 2.41.0.255.g8b1d071c50-goog