From nobody Mon Sep 29 20:17:11 2025 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 15FCEC25B0D for ; Tue, 16 Aug 2022 04:44:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231448AbiHPEog (ORCPT ); Tue, 16 Aug 2022 00:44:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232388AbiHPElH (ORCPT ); Tue, 16 Aug 2022 00:41:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B01D31E; Mon, 15 Aug 2022 13:32:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 267E461089; Mon, 15 Aug 2022 20:32:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE8EDC433D6; Mon, 15 Aug 2022 20:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660595539; bh=LppMEuUzo6b/Ex+fnTzrJEZen/CscpfIU86+ikvLlYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AYUHfg5T96oajLwxZt6mo5EHM85teMxgkgopNNJDG3tTQ2J7+qXTXarRium+X+D4X HqlYQxGOzozBR2x/p/doFMu4qfgphUoYmgIY6vlad+T6BEIe7D3rHsR7Cf8rMSLGfH kTNJ04DeXlR0fn40qp0bTiEKWxejuPDW6y3vEC7U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miaohe Lin , Huang Ying , Alistair Popple , Christoph Hellwig , Christoph Lameter , David Hildenbrand , David Howells , Mike Kravetz , Muchun Song , Oscar Salvador , Peter Xu , Andrew Morton , Sasha Levin , kernel test robot Subject: [PATCH 5.19 0765/1157] mm/migration: return errno when isolate_huge_page failed Date: Mon, 15 Aug 2022 20:02:01 +0200 Message-Id: <20220815180510.091011030@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Miaohe Lin [ Upstream commit 7ce82f4c3f3ead13a9d9498768e3b1a79975c4d8 ] We might fail to isolate huge page due to e.g. the page is under migration which cleared HPageMigratable. We should return errno in this case rather than always return 1 which could confuse the user, i.e. the caller might think all of the memory is migrated while the hugetlb page is left behind. We make the prototype of isolate_huge_page consistent with isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page to isolate_hugetlb as suggested by Muchun to improve the readability. Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com Fixes: e8db67eb0ded ("mm: migrate: move_pages() supports thp migration") Signed-off-by: Miaohe Lin Suggested-by: Huang Ying Reported-by: kernel test robot (build error) Cc: Alistair Popple Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Hildenbrand Cc: David Howells Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Peter Xu Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- include/linux/hugetlb.h | 6 +++--- mm/gup.c | 2 +- mm/hugetlb.c | 11 +++++------ mm/memory-failure.c | 2 +- mm/memory_hotplug.c | 2 +- mm/mempolicy.c | 2 +- mm/migrate.c | 7 ++++--- 7 files changed, 16 insertions(+), 16 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index e4cff27d1198..756b66ff025e 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -170,7 +170,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long fr= om, long to, vm_flags_t vm_flags); long hugetlb_unreserve_pages(struct inode *inode, long start, long end, long freed); -bool isolate_huge_page(struct page *page, struct list_head *list); +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); void putback_active_hugepage(struct page *page); @@ -376,9 +376,9 @@ static inline pte_t *huge_pte_offset(struct mm_struct *= mm, unsigned long addr, return NULL; } =20 -static inline bool isolate_huge_page(struct page *page, struct list_head *= list) +static inline int isolate_hugetlb(struct page *page, struct list_head *lis= t) { - return false; + return -EBUSY; } =20 static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb) diff --git a/mm/gup.c b/mm/gup.c index e2a39e30756d..fd3262ae92fc 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1900,7 +1900,7 @@ static long check_and_migrate_movable_pages(unsigned = long nr_pages, * Try to move out any movable page before pinning the range. */ if (folio_test_hugetlb(folio)) { - if (!isolate_huge_page(&folio->page, + if (isolate_hugetlb(&folio->page, &movable_page_list)) isolation_error_count++; continue; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index a18c071c294e..b7f007399be2 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2766,8 +2766,7 @@ static int alloc_and_dissolve_huge_page(struct hstate= *h, struct page *old_page, * Fail with -EBUSY if not possible. */ spin_unlock_irq(&hugetlb_lock); - if (!isolate_huge_page(old_page, list)) - ret =3D -EBUSY; + ret =3D isolate_hugetlb(old_page, list); spin_lock_irq(&hugetlb_lock); goto free_new; } else if (!HPageFreed(old_page)) { @@ -2843,7 +2842,7 @@ int isolate_or_dissolve_huge_page(struct page *page, = struct list_head *list) if (hstate_is_gigantic(h)) return -ENOMEM; =20 - if (page_count(head) && isolate_huge_page(head, list)) + if (page_count(head) && !isolate_hugetlb(head, list)) ret =3D 0; else if (!page_count(head)) ret =3D alloc_and_dissolve_huge_page(h, head, list); @@ -6966,15 +6965,15 @@ follow_huge_pgd(struct mm_struct *mm, unsigned long= address, pgd_t *pgd, int fla return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); } =20 -bool isolate_huge_page(struct page *page, struct list_head *list) +int isolate_hugetlb(struct page *page, struct list_head *list) { - bool ret =3D true; + int ret =3D 0; =20 spin_lock_irq(&hugetlb_lock); if (!PageHeadHuge(page) || !HPageMigratable(page) || !get_page_unless_zero(page)) { - ret =3D false; + ret =3D -EBUSY; goto unlock; } ClearHPageMigratable(page); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index da39ec8afca8..845369f839e1 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2178,7 +2178,7 @@ static bool isolate_page(struct page *page, struct li= st_head *pagelist) bool lru =3D PageLRU(page); =20 if (PageHuge(page)) { - isolated =3D isolate_huge_page(page, pagelist); + isolated =3D !isolate_hugetlb(page, pagelist); } else { if (lru) isolated =3D !isolate_lru_page(page); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 1213d0c67a53..649a50ed90f3 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1643,7 +1643,7 @@ do_migrate_range(unsigned long start_pfn, unsigned lo= ng end_pfn) =20 if (PageHuge(page)) { pfn =3D page_to_pfn(head) + compound_nr(head) - 1; - isolate_huge_page(head, &source); + isolate_hugetlb(head, &source); continue; } else if (PageTransHuge(page)) pfn =3D page_to_pfn(head) + thp_nr_pages(page) - 1; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d39b01fd52fe..9689919a2829 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -602,7 +602,7 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned lon= g hmask, /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */ if (flags & (MPOL_MF_MOVE_ALL) || (flags & MPOL_MF_MOVE && page_mapcount(page) =3D=3D 1)) { - if (!isolate_huge_page(page, qp->pagelist) && + if (isolate_hugetlb(page, qp->pagelist) && (flags & MPOL_MF_STRICT)) /* * Failed to isolate page but allow migrating pages diff --git a/mm/migrate.c b/mm/migrate.c index 6c1ea61f39d8..29b9faed4136 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -133,7 +133,7 @@ static void putback_movable_page(struct page *page) * * This function shall be used whenever the isolated pageset has been * built from lru, balloon, hugetlbfs page. See isolate_migratepages_range= () - * and isolate_huge_page(). + * and isolate_hugetlb(). */ void putback_movable_pages(struct list_head *l) { @@ -1633,8 +1633,9 @@ static int add_page_for_migration(struct mm_struct *m= m, unsigned long addr, =20 if (PageHuge(page)) { if (PageHead(page)) { - isolate_huge_page(page, pagelist); - err =3D 1; + err =3D isolate_hugetlb(page, pagelist); + if (!err) + err =3D 1; } } else { struct page *head; --=20 2.35.1