From nobody Mon Dec 29 00:37:19 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 F40A8C46CA0 for ; Mon, 4 Dec 2023 14:23:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345078AbjLDOW5 (ORCPT ); Mon, 4 Dec 2023 09:22:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235857AbjLDOWZ (ORCPT ); Mon, 4 Dec 2023 09:22:25 -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 CF7ED1720 for ; Mon, 4 Dec 2023 06:22:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701699738; 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=0rYG9NNO7tFTRIi4sOXhh6ZZDANHjsXpFzljN91NqwE=; b=bBBZr2L3F/wfak2zVi+bJFcURglvRlJ2bxcPAtLLewO2Q8vr9HvnCnzLkagf/Nj50xE1hs oCGi9gVd1Lomi5nWKV4eSDX0YgiBWowlm3vNy5DJf2thjEfEU36Wfpd9nm6e19unUfjkTb 48rDdOV4oSlmYHzLV7tiRPoI9I7v2NU= 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-658-L-pBgpvKP7yCqqoQs9ALwA-1; Mon, 04 Dec 2023 09:22:17 -0500 X-MC-Unique: L-pBgpvKP7yCqqoQs9ALwA-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 EF0598314FC; Mon, 4 Dec 2023 14:22:16 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.195.87]) by smtp.corp.redhat.com (Postfix) with ESMTP id 052CE2026D4C; Mon, 4 Dec 2023 14:22:14 +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 15/39] mm/huge_memory: batch rmap operations in __split_huge_pmd_locked() Date: Mon, 4 Dec 2023 15:21:22 +0100 Message-ID: <20231204142146.91437-16-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 use folio_add_anon_rmap_ptes(), batching the rmap operations. While at it, use more folio operations (but only in the code branch we're touching), use VM_WARN_ON_FOLIO(), and pass RMAP_COMPOUND instead of manually setting PageAnonExclusive. We should never see non-anon pages on that branch: otherwise, the existing page_add_anon_rmap() call would have been flawed already. Signed-off-by: David Hildenbrand --- mm/huge_memory.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cb33c6e0404cf..2c037ab3f4916 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2099,6 +2099,7 @@ static void __split_huge_pmd_locked(struct vm_area_st= ruct *vma, pmd_t *pmd, unsigned long haddr, bool freeze) { struct mm_struct *mm =3D vma->vm_mm; + struct folio *folio; struct page *page; pgtable_t pgtable; pmd_t old_pmd, _pmd; @@ -2194,16 +2195,18 @@ static void __split_huge_pmd_locked(struct vm_area_= struct *vma, pmd_t *pmd, uffd_wp =3D pmd_swp_uffd_wp(old_pmd); } else { page =3D pmd_page(old_pmd); + folio =3D page_folio(page); if (pmd_dirty(old_pmd)) { dirty =3D true; - SetPageDirty(page); + folio_set_dirty(folio); } write =3D pmd_write(old_pmd); young =3D pmd_young(old_pmd); soft_dirty =3D pmd_soft_dirty(old_pmd); uffd_wp =3D pmd_uffd_wp(old_pmd); =20 - VM_BUG_ON_PAGE(!page_count(page), page); + VM_WARN_ON_FOLIO(!folio_ref_count(folio), folio); + VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio); =20 /* * Without "freeze", we'll simply split the PMD, propagating the @@ -2220,11 +2223,18 @@ static void __split_huge_pmd_locked(struct vm_area_= struct *vma, pmd_t *pmd, * * See page_try_share_anon_rmap(): invalidate PMD first. */ - anon_exclusive =3D PageAnon(page) && PageAnonExclusive(page); + anon_exclusive =3D PageAnonExclusive(page); if (freeze && anon_exclusive && page_try_share_anon_rmap(page)) freeze =3D false; - if (!freeze) - page_ref_add(page, HPAGE_PMD_NR - 1); + if (!freeze) { + rmap_t rmap_flags =3D RMAP_NONE; + + folio_ref_add(folio, HPAGE_PMD_NR - 1); + if (anon_exclusive) + rmap_flags =3D RMAP_EXCLUSIVE; + folio_add_anon_rmap_ptes(folio, page, HPAGE_PMD_NR, + vma, haddr, rmap_flags); + } } =20 /* @@ -2267,8 +2277,6 @@ static void __split_huge_pmd_locked(struct vm_area_st= ruct *vma, pmd_t *pmd, entry =3D mk_pte(page + i, READ_ONCE(vma->vm_page_prot)); if (write) entry =3D pte_mkwrite(entry, vma); - if (anon_exclusive) - SetPageAnonExclusive(page + i); if (!young) entry =3D pte_mkold(entry); /* NOTE: this may set soft-dirty too on some archs */ @@ -2278,7 +2286,6 @@ static void __split_huge_pmd_locked(struct vm_area_st= ruct *vma, pmd_t *pmd, entry =3D pte_mksoft_dirty(entry); if (uffd_wp) entry =3D pte_mkuffd_wp(entry); - page_add_anon_rmap(page + i, vma, addr, RMAP_NONE); } VM_BUG_ON(!pte_none(ptep_get(pte))); set_pte_at(mm, addr, pte, entry); --=20 2.41.0