From nobody Sun Dec 14 11:47:57 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 98A0013F013 for ; Wed, 14 Feb 2024 20:44:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707943500; cv=none; b=YheeeLTSi+JE3MKH2L+67+awVi1HsOq8I8Uur2F7r+UYZglHLH6yGElGp7hQ6xBJx8KynTDw2BkOiclDJkuQrrHG9WwrlRSM/AWJH8blA/+IwKscdfrBYzyloHo4spbkbnI31Jev25jDuSESdZ6B9y9fWZdsKSbb+aBYEgMvWU8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707943500; c=relaxed/simple; bh=gJjdcDN9SIZ57EMSsnxvz4s6wGh9ngGev4G0JhDn5Lw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rHWEGwB/MRJvgYRGPAYnJl5QHMjIk4xfJqbQ2jsWVy7+zwWV5Ac/tbu9En/P5tFn7uf4yIYhp5RZZclz/huTieFSFaHCo5faDGWl+Q2IMF88GPT4xeFKceScL/z099fBpbikN5NxPe1npFyjrhRVPTeg8N6YacW6N9id5gkrhh0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=jPkqsZIp; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jPkqsZIp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707943497; 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=M/Ux9HRgPwmdR3zuVPtEfBlFP5wVpYCc/8Whwmc2o7c=; b=jPkqsZIpAhXubwcPIQoGJd4sJN/P/hl1VJhVEMIqk+U2e7zkIQu8pwMZJD+jV+eMSqHyKS 3xjOGiTSolq9lVvkwxGzLYsKIVo882ujB49Wdj6CzlZf0PhIGQxpCP+fKkUXEtBKZz1Gbv oWCEEZyKBNE7EnIExK4hDC2JALzpXvw= 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-460-Ud6bEsrlM92gS6OHI6pxZA-1; Wed, 14 Feb 2024 15:44:54 -0500 X-MC-Unique: Ud6bEsrlM92gS6OHI6pxZA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (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 DDD578630C4; Wed, 14 Feb 2024 20:44:52 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.194.174]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4741B1C060B1; Wed, 14 Feb 2024 20:44:49 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , Andrew Morton , Matthew Wilcox , Ryan Roberts , Catalin Marinas , Yin Fengwei , Michal Hocko , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Michael Ellerman , Christophe Leroy , "Naveen N. Rao" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org Subject: [PATCH v3 03/10] mm/memory: further separate anon and pagecache folio handling in zap_present_pte() Date: Wed, 14 Feb 2024 21:44:28 +0100 Message-ID: <20240214204435.167852-4-david@redhat.com> In-Reply-To: <20240214204435.167852-1-david@redhat.com> References: <20240214204435.167852-1-david@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Content-Type: text/plain; charset="utf-8" We don't need up-to-date accessed-dirty information for anon folios and can simply work with the ptent we already have. Also, we know the RSS counter we want to update. We can safely move arch_check_zapped_pte() + tlb_remove_tlb_entry() + zap_install_uffd_wp_if_needed() after updating the folio and RSS. While at it, only call zap_install_uffd_wp_if_needed() if there is even any chance that pte_install_uffd_wp_if_needed() would do *something*. That is, just don't bother if uffd-wp does not apply. Reviewed-by: Ryan Roberts Signed-off-by: David Hildenbrand --- mm/memory.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 4da6923709b2..7a3ebb6e5909 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1552,12 +1552,9 @@ static inline void zap_present_pte(struct mmu_gather= *tlb, folio =3D page_folio(page); if (unlikely(!should_zap_folio(details, folio))) return; - ptent =3D ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); - arch_check_zapped_pte(vma, ptent); - tlb_remove_tlb_entry(tlb, pte, addr); - zap_install_uffd_wp_if_needed(vma, addr, pte, details, ptent); =20 if (!folio_test_anon(folio)) { + ptent =3D ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); if (pte_dirty(ptent)) { folio_mark_dirty(folio); if (tlb_delay_rmap(tlb)) { @@ -1567,8 +1564,17 @@ static inline void zap_present_pte(struct mmu_gather= *tlb, } if (pte_young(ptent) && likely(vma_has_recency(vma))) folio_mark_accessed(folio); + rss[mm_counter(folio)]--; + } else { + /* We don't need up-to-date accessed/dirty bits. */ + ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); + rss[MM_ANONPAGES]--; } - rss[mm_counter(folio)]--; + arch_check_zapped_pte(vma, ptent); + tlb_remove_tlb_entry(tlb, pte, addr); + if (unlikely(userfaultfd_pte_wp(vma, ptent))) + zap_install_uffd_wp_if_needed(vma, addr, pte, details, ptent); + if (!delay_rmap) { folio_remove_rmap_pte(folio, page, vma); if (unlikely(page_mapcount(page) < 0)) --=20 2.43.0