From nobody Mon Dec 29 00:37:53 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 05625C4167B for ; Mon, 4 Dec 2023 14:24:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235920AbjLDOXy (ORCPT ); Mon, 4 Dec 2023 09:23:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345398AbjLDOXL (ORCPT ); Mon, 4 Dec 2023 09:23:11 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34EBE1BD5 for ; Mon, 4 Dec 2023 06:22:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701699757; 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=MMp/rsTScJnGvEHSBNzvW50JXqbYQ0nspFlZU7tqJ/c=; b=PaCFXDen46GeXpgUnGOLkf1/jSHuq7Tx0C02rdNeVRRBm79WRaQ9dI5KiJVCRIusdPYi7I bOnxKcEGu5PTMptePOuGSVb9gbQmx0YdcShGQh3+Mnj21KKT6oDj1M5ag/CZ9fcpW3HE8g kVknUCuH5xnXnBLC3/Dx33nnuLKzwlA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-494-KFAuLerwMeGWU5ALc3K4CQ-1; Mon, 04 Dec 2023 09:22:32 -0500 X-MC-Unique: KFAuLerwMeGWU5ALc3K4CQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4F04185A58C; Mon, 4 Dec 2023 14:22:32 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.195.87]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3A5802026D4C; Mon, 4 Dec 2023 14:22:30 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , Andrew Morton , "Matthew Wilcox (Oracle)" , Hugh Dickins , Ryan Roberts , Yin Fengwei , Mike Kravetz , Muchun Song , Peter Xu Subject: [PATCH RFC 23/39] mm/rmap: introduce folio_remove_rmap_[pte|ptes|pmd]() Date: Mon, 4 Dec 2023 15:21:30 +0100 Message-ID: <20231204142146.91437-24-david@redhat.com> In-Reply-To: <20231204142146.91437-1-david@redhat.com> References: <20231204142146.91437-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Let's mimic what we did with folio_add_file_rmap_*() and folio_add_anon_rmap_*() so we can similarly replace page_remove_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. We're adding folio_remove_rmap_ptes() handling right away, as we want to use that soon for batching rmap operations when unmapping PTE-mapped large folios. Signed-off-by: David Hildenbrand --- include/linux/rmap.h | 6 ++++ mm/rmap.c | 76 ++++++++++++++++++++++++++++++++++++-------- 2 files changed, 68 insertions(+), 14 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 017b216915f19..dd4ffb1d8ae04 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -241,6 +241,12 @@ void folio_add_file_rmap_pmd(struct folio *, struct pa= ge *, struct vm_area_struct *); void page_remove_rmap(struct page *, struct vm_area_struct *, bool compound); +void folio_remove_rmap_ptes(struct folio *, struct page *, unsigned int nr, + struct vm_area_struct *); +#define folio_remove_rmap_pte(folio, page, vma) \ + folio_remove_rmap_ptes(folio, page, 1, vma) +void folio_remove_rmap_pmd(struct folio *, struct page *, + struct vm_area_struct *); =20 void hugetlb_add_anon_rmap(struct folio *, struct vm_area_struct *, unsigned long address, rmap_t flags); diff --git a/mm/rmap.c b/mm/rmap.c index 3587225055c5e..50b6909157ac1 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1463,25 +1463,36 @@ void page_remove_rmap(struct page *page, struct vm_= area_struct *vma, bool compound) { struct folio *folio =3D page_folio(page); + + if (likely(!compound)) + folio_remove_rmap_pte(folio, page, vma); + else + folio_remove_rmap_pmd(folio, page, vma); +} + +static __always_inline void __folio_remove_rmap(struct folio *folio, + struct page *page, unsigned int nr_pages, + struct vm_area_struct *vma, enum rmap_mode mode) +{ atomic_t *mapped =3D &folio->_nr_pages_mapped; - int nr =3D 0, nr_pmdmapped =3D 0; - bool last; + int last, nr =3D 0, nr_pmdmapped =3D 0; enum node_stat_item idx; =20 - VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio); - VM_BUG_ON_PAGE(compound && !PageHead(page), page); + __folio_rmap_sanity_checks(folio, page, nr_pages, mode); =20 /* Is page being unmapped by PTE? Is this its last map to be removed? */ - if (likely(!compound)) { - last =3D atomic_add_negative(-1, &page->_mapcount); - nr =3D last; - if (last && folio_test_large(folio)) { - nr =3D atomic_dec_return_relaxed(mapped); - nr =3D (nr < COMPOUND_MAPPED); - } - } else if (folio_test_pmd_mappable(folio)) { - /* That test is redundant: it's for safety or to optimize out */ + if (likely(mode =3D=3D RMAP_MODE_PTE)) { + do { + last =3D atomic_add_negative(-1, &page->_mapcount); + if (last && folio_test_large(folio)) { + last =3D atomic_dec_return_relaxed(mapped); + last =3D (last < COMPOUND_MAPPED); + } =20 + if (last) + nr++; + } while (page++, --nr_pages > 0); + } else if (mode =3D=3D RMAP_MODE_PMD) { last =3D atomic_add_negative(-1, &folio->_entire_mapcount); if (last) { nr =3D atomic_sub_return_relaxed(COMPOUND_MAPPED, mapped); @@ -1517,7 +1528,7 @@ void page_remove_rmap(struct page *page, struct vm_ar= ea_struct *vma, * is still mapped. */ if (folio_test_pmd_mappable(folio) && folio_test_anon(folio)) - if (!compound || nr < nr_pmdmapped) + if (mode =3D=3D RMAP_MODE_PTE || nr < nr_pmdmapped) deferred_split_folio(folio); } =20 @@ -1532,6 +1543,43 @@ void page_remove_rmap(struct page *page, struct vm_a= rea_struct *vma, munlock_vma_folio(folio, vma); } =20 +/** + * folio_remove_rmap_ptes - remove PTE mappings from a page range of a fol= io + * @folio: The folio to remove the mappings from + * @page: The first page to remove + * @nr_pages: The number of pages that will be removed from the mapping + * @vma: The vm area from which the mappings are removed + * + * The page range of the folio is defined by [page, page + nr_pages) + * + * The caller needs to hold the page table lock. + */ +void folio_remove_rmap_ptes(struct folio *folio, struct page *page, + unsigned int nr_pages, struct vm_area_struct *vma) +{ + __folio_remove_rmap(folio, page, nr_pages, vma, RMAP_MODE_PTE); +} + +/** + * folio_remove_rmap_pmd - remove a PMD mapping from a page range of a fol= io + * @folio: The folio to remove the mapping from + * @page: The first page to remove + * @vma: The vm area from which the mapping is removed + * + * The page range of the folio is defined by [page, page + HPAGE_PMD_NR) + * + * The caller needs to hold the page table lock. + */ +void folio_remove_rmap_pmd(struct folio *folio, struct page *page, + struct vm_area_struct *vma) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + __folio_remove_rmap(folio, page, HPAGE_PMD_NR, vma, RMAP_MODE_PMD); +#else + WARN_ON_ONCE(true); +#endif +} + /* * @arg: enum ttu_flags will be passed to this argument */ --=20 2.41.0