From nobody Fri Dec 19 14:35:24 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 547B0C10F05 for ; Mon, 11 Dec 2023 15:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344400AbjLKP5N (ORCPT ); Mon, 11 Dec 2023 10:57:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344472AbjLKP5K (ORCPT ); Mon, 11 Dec 2023 10:57:10 -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 BA6F6F3 for ; Mon, 11 Dec 2023 07:57:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702310230; 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=eQFoT8xrLd9LUZRih2ZF29493QEHiYzpAeVB57UisD0=; b=cK/oeP1ouam/D+5+S4uhtaHIB7DBFVudnPTmX7aEjMpRgaClH695MluwewQAhP22ob9dVc GFPnwk9nS1q1Y7huvCaxx2lx//1oG1beysZJP1TcN6MFe1QsOAzCZrIlcwt7FSXYHMoy2j pKCjW4VFUrzdyRZFWKKxH+KecZ79IJw= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-620-xxnUSZcjMXupZYk_PaLjmg-1; Mon, 11 Dec 2023 10:57:05 -0500 X-MC-Unique: xxnUSZcjMXupZYk_PaLjmg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (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 8D0001C01B3A; Mon, 11 Dec 2023 15:57:04 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.192.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2EA5E1121306; Mon, 11 Dec 2023 15:57:01 +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 v1 03/39] mm/rmap: introduce and use hugetlb_add_file_rmap() Date: Mon, 11 Dec 2023 16:56:16 +0100 Message-ID: <20231211155652.131054-4-david@redhat.com> In-Reply-To: <20231211155652.131054-1-david@redhat.com> References: <20231211155652.131054-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Right now we're using page_dup_file_rmap() in some cases where "ordinary" rmap code would have used page_add_file_rmap(). So let's introduce and use hugetlb_add_file_rmap() instead. We won't be adding a "hugetlb_dup_file_rmap()" functon for the fork() case, as it would be doing the same: "dup" is just an optimization for "add". What remains is a single page_dup_file_rmap() call in fork() code. Reviewed-by: Yin Fengwei Signed-off-by: David Hildenbrand Reviewed-by: Ryan Roberts --- include/linux/rmap.h | 7 +++++++ mm/hugetlb.c | 6 +++--- mm/migrate.c | 2 +- 3 files changed, 11 insertions(+), 4 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index d85bd1d4de04..91178d1aa028 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -213,6 +213,13 @@ void hugetlb_add_anon_rmap(struct folio *, struct vm_a= rea_struct *, void hugetlb_add_new_anon_rmap(struct folio *, struct vm_area_struct *, unsigned long address); =20 +static inline void hugetlb_add_file_rmap(struct folio *folio) +{ + VM_WARN_ON_FOLIO(folio_test_anon(folio), folio); + + atomic_inc(&folio->_entire_mapcount); +} + static inline void hugetlb_remove_rmap(struct folio *folio) { atomic_dec(&folio->_entire_mapcount); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index ef48ae673890..57e898187931 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5408,7 +5408,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, st= ruct mm_struct *src, * sleep during the process. */ if (!folio_test_anon(pte_folio)) { - page_dup_file_rmap(&pte_folio->page, true); + hugetlb_add_file_rmap(pte_folio); } else if (page_try_dup_anon_rmap(&pte_folio->page, true, src_vma)) { pte_t src_pte_old =3D entry; @@ -6279,7 +6279,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *m= m, if (anon_rmap) hugetlb_add_new_anon_rmap(folio, vma, haddr); else - page_dup_file_rmap(&folio->page, true); + hugetlb_add_file_rmap(folio); new_pte =3D make_huge_pte(vma, &folio->page, ((vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_SHARED))); /* @@ -6730,7 +6730,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, goto out_release_unlock; =20 if (folio_in_pagecache) - page_dup_file_rmap(&folio->page, true); + hugetlb_add_file_rmap(folio); else hugetlb_add_new_anon_rmap(folio, dst_vma, dst_addr); =20 diff --git a/mm/migrate.c b/mm/migrate.c index 4cb849fa0dd2..de9d94b99ab7 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -252,7 +252,7 @@ static bool remove_migration_pte(struct folio *folio, hugetlb_add_anon_rmap(folio, vma, pvmw.address, rmap_flags); else - page_dup_file_rmap(new, true); + hugetlb_add_file_rmap(folio); set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte, psize); } else --=20 2.43.0