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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6D921C47DA9 for ; Tue, 30 Jan 2024 08:14:48 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TPHyZ70sHz3cX6 for ; Tue, 30 Jan 2024 19:14:46 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=ryan.roberts@arm.com; receiver=lists.ozlabs.org) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4TPHy53jYyz2yVT for ; Tue, 30 Jan 2024 19:14:18 +1100 (AEDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 02A1DDA7; Tue, 30 Jan 2024 00:14:28 -0800 (PST) Received: from [10.57.79.54] (unknown [10.57.79.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2A6013F738; Tue, 30 Jan 2024 00:13:39 -0800 (PST) Message-ID: <40e87333-4da9-4497-a117-9885986e376a@arm.com> Date: Tue, 30 Jan 2024 08:13:38 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/9] mm/memory: factor out zapping of present pte into zap_present_pte() Content-Language: en-GB To: David Hildenbrand , linux-kernel@vger.kernel.org References: <20240129143221.263763-1-david@redhat.com> <20240129143221.263763-2-david@redhat.com> From: Ryan Roberts In-Reply-To: <20240129143221.263763-2-david@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Alexander Gordeev , Christian Borntraeger , Arnd Bergmann , Vasily Gorbik , Peter Zijlstra , "Aneesh Kumar K.V" , linuxppc-dev@lists.ozlabs.org, Matthew Wilcox , linux-mm@kvack.org, Nick Piggin , Catalin Marinas , "Naveen N. Rao" , Andrew Morton , Will Deacon , Heiko Carstens , Sven Schnelle Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 29/01/2024 14:32, David Hildenbrand wrote: > Let's prepare for further changes by factoring out processing of present > PTEs. > > Signed-off-by: David Hildenbrand > --- > mm/memory.c | 92 ++++++++++++++++++++++++++++++----------------------- > 1 file changed, 52 insertions(+), 40 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index b05fd28dbce1..50a6c79c78fc 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1532,13 +1532,61 @@ zap_install_uffd_wp_if_needed(struct vm_area_struct *vma, > pte_install_uffd_wp_if_needed(vma, addr, pte, pteval); > } > > +static inline void zap_present_pte(struct mmu_gather *tlb, > + struct vm_area_struct *vma, pte_t *pte, pte_t ptent, > + unsigned long addr, struct zap_details *details, > + int *rss, bool *force_flush, bool *force_break) > +{ > + struct mm_struct *mm = tlb->mm; > + bool delay_rmap = false; > + struct folio *folio; You need to init this to NULL otherwise its a random value when calling should_zap_folio() if vm_normal_page() returns NULL. > + struct page *page; > + > + page = vm_normal_page(vma, addr, ptent); > + if (page) > + folio = page_folio(page); > + > + if (unlikely(!should_zap_folio(details, folio))) > + return; > + ptent = 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); > + if (unlikely(!page)) { > + ksm_might_unmap_zero_page(mm, ptent); > + return; > + } > + > + if (!folio_test_anon(folio)) { > + if (pte_dirty(ptent)) { > + folio_mark_dirty(folio); > + if (tlb_delay_rmap(tlb)) { > + delay_rmap = true; > + *force_flush = true; > + } > + } > + if (pte_young(ptent) && likely(vma_has_recency(vma))) > + folio_mark_accessed(folio); > + } > + rss[mm_counter(folio)]--; > + if (!delay_rmap) { > + folio_remove_rmap_pte(folio, page, vma); > + if (unlikely(page_mapcount(page) < 0)) > + print_bad_pte(vma, addr, ptent, page); > + } > + if (unlikely(__tlb_remove_page(tlb, page, delay_rmap))) { > + *force_flush = true; > + *force_break = true; > + } > +} > + > static unsigned long zap_pte_range(struct mmu_gather *tlb, > struct vm_area_struct *vma, pmd_t *pmd, > unsigned long addr, unsigned long end, > struct zap_details *details) > { > + bool force_flush = false, force_break = false; > struct mm_struct *mm = tlb->mm; > - int force_flush = 0; > int rss[NR_MM_COUNTERS]; > spinlock_t *ptl; > pte_t *start_pte; > @@ -1565,45 +1613,9 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, > break; > > if (pte_present(ptent)) { > - unsigned int delay_rmap; > - > - page = vm_normal_page(vma, addr, ptent); > - if (page) > - folio = page_folio(page); > - > - if (unlikely(!should_zap_folio(details, folio))) > - continue; > - ptent = 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); > - if (unlikely(!page)) { > - ksm_might_unmap_zero_page(mm, ptent); > - continue; > - } > - > - delay_rmap = 0; > - if (!folio_test_anon(folio)) { > - if (pte_dirty(ptent)) { > - folio_mark_dirty(folio); > - if (tlb_delay_rmap(tlb)) { > - delay_rmap = 1; > - force_flush = 1; > - } > - } > - if (pte_young(ptent) && likely(vma_has_recency(vma))) > - folio_mark_accessed(folio); > - } > - rss[mm_counter(folio)]--; > - if (!delay_rmap) { > - folio_remove_rmap_pte(folio, page, vma); > - if (unlikely(page_mapcount(page) < 0)) > - print_bad_pte(vma, addr, ptent, page); > - } > - if (unlikely(__tlb_remove_page(tlb, page, delay_rmap))) { > - force_flush = 1; > + zap_present_pte(tlb, vma, pte, ptent, addr, details, > + rss, &force_flush, &force_break); > + if (unlikely(force_break)) { > addr += PAGE_SIZE; > break; > }