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 88621C43334 for ; Mon, 4 Jul 2022 01:40:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230189AbiGDBkc (ORCPT ); Sun, 3 Jul 2022 21:40:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229648AbiGDBk2 (ORCPT ); Sun, 3 Jul 2022 21:40:28 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E01AC62DF for ; Sun, 3 Jul 2022 18:40:26 -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 ams.source.kernel.org (Postfix) with ESMTPS id 9234DB80CED for ; Mon, 4 Jul 2022 01:40:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 485AAC341C6; Mon, 4 Jul 2022 01:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1656898824; bh=Gz6s4iUkJo/ybcWvtSMQofJetA508/EEh+vLPCaPni8=; h=Date:To:From:Subject:From; b=w+I0UXWtiEFk/tpyLfxdrS+/4v0tlxtsCSZf9pUNe92PQn6e7t2yBw9aNElEJNrP7 oQ5S9iF4VaBhYp+LwUSM/xNSqkIvdT8Hyy1ooGpVnTbm+jfCb+WYCoAM/OmUb/xL7K OWQ7nnq4v6d4nlHIqIKbRF9utzGav9a6wHmUPQEM= Date: Sun, 03 Jul 2022 18:40:23 -0700 To: mm-commits@vger.kernel.org, songmuchun@bytedance.com, shy828301@gmail.com, osalvador@suse.de, mike.kravetz@oracle.com, liushixin2@huawei.com, linmiaohe@huawei.com, david@redhat.com, naoya.horiguchi@nec.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch added to mm-unstable branch Message-Id: <20220704014024.485AAC341C6@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/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry has been added to the -mm mm-unstable branch. Its filename is mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Naoya Horiguchi Subject: mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry Date: Mon, 4 Jul 2022 10:33:06 +0900 follow_pud_mask() does not support non-present pud entry now. As long as I tested on x86_64 server, follow_pud_mask() still simply returns no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe user-visible effect should happen. But generally we should call follow_huge_pud() for non-present pud entry for 1GB hugetlb page. Update pud_huge() and follow_huge_pud() to handle non-present pud entries. The changes are similar to previous works for pud entries commit e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") and commit cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present hugepage"). Link: https://lkml.kernel.org/r/20220704013312.2415700-4-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Cc: David Hildenbrand Cc: Liu Shixin Cc: Miaohe Lin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton --- arch/x86/mm/hugetlbpage.c | 8 +++++++- mm/hugetlb.c | 32 ++++++++++++++++++++++++++++++-- 2 files changed, 37 insertions(+), 3 deletions(-) --- a/arch/x86/mm/hugetlbpage.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry +++ a/arch/x86/mm/hugetlbpage.c @@ -30,9 +30,15 @@ int pmd_huge(pmd_t pmd) (pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT; } +/* + * pud_huge() returns 1 if @pud is hugetlb related entry, that is normal + * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry. + * Otherwise, returns 0. + */ int pud_huge(pud_t pud) { - return !!(pud_val(pud) & _PAGE_PSE); + return !pud_none(pud) && + (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT; } #ifdef CONFIG_HUGETLB_PAGE --- a/mm/hugetlb.c~mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry +++ a/mm/hugetlb.c @@ -6993,10 +6993,38 @@ struct page * __weak follow_huge_pud(struct mm_struct *mm, unsigned long address, pud_t *pud, int flags) { - if (flags & (FOLL_GET | FOLL_PIN)) + struct page *page = NULL; + spinlock_t *ptl; + pte_t pte; + + if (WARN_ON_ONCE(flags & FOLL_PIN)) return NULL; - return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); +retry: + ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud); + if (!pud_huge(*pud)) + goto out; + pte = huge_ptep_get((pte_t *)pud); + if (pte_present(pte)) { + page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); + if (WARN_ON_ONCE(!try_grab_page(page, flags))) { + page = NULL; + goto out; + } + } else { + if (is_hugetlb_entry_migration(pte)) { + spin_unlock(ptl); + __migration_entry_wait(mm, (pte_t *)pud, ptl); + goto retry; + } + /* + * hwpoisoned entry is treated as no_page_table in + * follow_page_mask(). + */ + } +out: + spin_unlock(ptl); + return page; } struct page * __weak _ Patches currently in -mm which might be from naoya.horiguchi@nec.com are mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch mm-hwpoison-make-__page_handle_poison-returns-int.patch mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch