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 5F4B3C4167B for ; Tue, 8 Feb 2022 22:26:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386529AbiBHWZr (ORCPT ); Tue, 8 Feb 2022 17:25:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1386819AbiBHVPy (ORCPT ); Tue, 8 Feb 2022 16:15:54 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E427BC0612BA for ; Tue, 8 Feb 2022 13:15:53 -0800 (PST) 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 80D6A61617 for ; Tue, 8 Feb 2022 21:15:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFC81C004E1; Tue, 8 Feb 2022 21:15:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1644354952; bh=xiHYnC9NwTqCgST1OccFKRWCwhY0ZdbFtepWRm6soUs=; h=Date:To:From:Subject:From; b=tVd4SKHADs6eI3J3F8IMmDfzTwO0wMJyY+gf+A9R7yW5rZZAxFKLUWjwos/V9+3+D 7LdGdNjssCz7f2aAd8Ku0rkCp9VAB7Z3+uFRanSa0jt8wp0sNduxUw4iWRk02nAoTw zA9jSeuAm2At2ycLXJgyDhKAIg2hCvrvc3uGa/Co= Date: Tue, 08 Feb 2022 13:15:52 -0800 To: mm-commits@vger.kernel.org, ziy@nvidia.com, willy@infradead.org, rientjes@google.com, mike.kravetz@oracle.com, lars.persson@axis.com, kirill.shutemov@linux.intel.com, duanxiongchun@bytedance.com, almasrymina@google.com, songmuchun@bytedance.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch added to -mm tree Message-Id: <20220208211552.CFC81C004E1@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: fix missing cache flush for all tail pages of compound page has been added to the -mm tree. Its filename is mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Muchun Song Subject: mm: fix missing cache flush for all tail pages of compound page The D-cache maintenance inside move_to_new_page() only consider one page, there is still D-cache maintenance issue for tail pages of compound page (e.g. THP or HugeTLB). THP migration is only enabled on x86_64, ARM64 and powerpc, while powerpc and arm64 need to maintain the consistency between I-Cache and D-Cache, which depends on flush_dcache_page() to maintain the consistency between I-Cache and D-Cache. But there are no issues on arm64 and powerpc since they already consider the compound page cache flushing in their icache flush function. HugeTLB migration is enabled on arm, arm64, mips, parisc, powerpc, riscv, s390 and sh, while arm has handled the compound page cache flush in flush_dcache_page(), but most others do not. In theory, the issue exists on many architectures. Fix this by not using flush_dcache_folio() since it is not backportable. Link: https://lkml.kernel.org/r/20220208073617.70342-3-songmuchun@bytedance.com Fixes: 290408d4a250 ("hugetlb: hugepage migration core") Signed-off-by: Muchun Song Reviewed-by: Zi Yan Cc: David Rientjes Cc: Kirill A. Shutemov Cc: Lars Persson Cc: Matthew Wilcox Cc: Mike Kravetz Cc: Mina Almasry Cc: Xiongchun Duan Signed-off-by: Andrew Morton --- mm/migrate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/mm/migrate.c~mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page +++ a/mm/migrate.c @@ -916,9 +916,12 @@ static int move_to_new_page(struct page if (!PageMappingFlags(page)) page->mapping = NULL; - if (likely(!is_zone_device_page(newpage))) - flush_dcache_page(newpage); + if (likely(!is_zone_device_page(newpage))) { + int i, nr = compound_nr(newpage); + for (i = 0; i < nr; i++) + flush_dcache_page(newpage + i); + } } out: return rc; _ Patches currently in -mm which might be from songmuchun@bytedance.com are mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd.patch mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch mm-hugetlb-fix-missing-cache-flush-in-copy_huge_page_from_user.patch mm-hugetlb-fix-missing-cache-flush-in-hugetlb_mcopy_atomic_pte.patch mm-replace-multiple-dcache-flush-with-flush_dcache_folio.patch mm-hugetlb-free-the-2nd-vmemmap-page-associated-with-each-hugetlb-page.patch mm-hugetlb-replace-hugetlb_free_vmemmap_enabled-with-a-static_key.patch mm-sparsemem-use-page-table-lock-to-protect-kernel-pmd-operations.patch selftests-vm-add-a-hugetlb-test-case.patch mm-sparsemem-move-vmemmap-related-to-hugetlb-to-config_hugetlb_page_free_vmemmap.patch