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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2E9FC48260 for ; Thu, 8 Feb 2024 06:29:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7EC0B6B00AA; Thu, 8 Feb 2024 01:29:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 79C6F6B00AB; Thu, 8 Feb 2024 01:29:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 68C4D6B00AD; Thu, 8 Feb 2024 01:29:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 5646C6B00AA for ; Thu, 8 Feb 2024 01:29:49 -0500 (EST) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 22B7A805C4 for ; Thu, 8 Feb 2024 06:29:49 +0000 (UTC) X-FDA: 81767660898.28.7DFB45A Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf06.hostedemail.com (Postfix) with ESMTP id 71658180018 for ; Thu, 8 Feb 2024 06:29:47 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Phoix+90; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf06.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1707373787; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=QMLG9oozfxuYK2nmPIL28W2MpYx2E+IKhvZWw/4oQwI=; b=UieFn79o+kRpvqgohotkfOgQQIY0yemKizxaKeyK/bLVBLH65NeLeM1g/Afeb5fBo1zi3X cQaJO6l7ygKFBUfGns1dwWwUoPDRBB45Zu0yc1QAn615o9xaOsEb9zcQsjP4KJxWVEWBA0 cHvWBLvDvinPwZlITEY7uSXJs18EX3k= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Phoix+90; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf06.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1707373787; a=rsa-sha256; cv=none; b=jQbMIpcX23A5/E/fkJLELpySm1gd+AKfOWUQC+VFko795xBA4iXdnfKFKpi8Hyfd+OSpS2 M3LjZXGlzxBliVNXF0Vq85n78IMPhQKCC7tGSZKydjB6srSnwYGXmmCrpDoOvEdwTrX9bp 9exJV6/wp4rXuj7tyW8B+9b2GCnc1p8= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 8BB1E61B29; Thu, 8 Feb 2024 06:29:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E21FC433F1; Thu, 8 Feb 2024 06:29:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707373786; bh=x4GCLa2xzNhu7jlHpC2LrDTqBpAccwVcIjWuUAdJzgc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Phoix+90khL4IEhQ6gpSoCEIa7eKrFuowZSgj42G9vOi8dSlpe1gQK0YyWgYKp+4r sPLY9+CUFb9aZvZlJVuQqwKhWZ+pa+B4zWmW6ij44vrjGh7IL5UzkD3sKKzoxbKYee QNwaU30tJ0UF6MuasMfjEGa+A4FY8V6otf3jfYDzeJPTIubtszyNvCkdBsoVBCTCKZ +W8z7CCvQhm6qI593PxMf1LOB8FDsoWbQ3LesFfp+jH1tSwZzvF1v7s5703XCDTQvu YYI3y/4CVWlLjbUJLn8zUCRy2xy0Roln1eAOTnw74B+sWgLw7OSbGWrqA5wjWVRClH ouB/3F6aDobjA== Date: Thu, 8 Feb 2024 08:29:21 +0200 From: Mike Rapoport To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Matthew Wilcox , Ryan Roberts , Russell King , Catalin Marinas , Will Deacon , Dinh Nguyen , Michael Ellerman , Nicholas Piggin , Christophe Leroy , "Aneesh Kumar K.V" , "Naveen N. Rao" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , "David S. Miller" , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org Subject: Re: [PATCH v3 11/15] mm/memory: factor out copying the actual PTE in copy_present_pte() Message-ID: References: <20240129124649.189745-1-david@redhat.com> <20240129124649.189745-12-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240129124649.189745-12-david@redhat.com> X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 71658180018 X-Stat-Signature: 4gzaotmrgq1q7dwzipqpkcxbhx71pmxi X-HE-Tag: 1707373787-162533 X-HE-Meta: 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 EcpVfoAZ JY8H9HhamJ7nThOmK/wDYxHIv9/TylXTRWWVFAjLGEP3woxGgmq+TpDMw0vCsYzFJB7RFnA2INoS8Z2qV2OdTEqcFmfftffN8HNLitfRj/zB2vb2EvXWFfK2PNH1cFjKZ2iTrPwBr+pRTupfNSCHAdhb2GBLeG7/HAhJaIsxuflbttxy2Brolon3SP9hAl9OUTSvrtUwl5NCXnFHcAwdHMYWvJN1Rjqjjs1rgQaiWUQkEjVXYGwcamfPBClXSxgcwIvzdDYZNI5ZwrC7pxpn8cHMj5J3IyVO5lpCN4tQHaXIJV441NiQkvYywq3V7f6x53kE1yLqztTMWvc3tkvva+Fv0gM37BMYo34y1L66ISs69Raim1TkqgBercLaew1hbuFje X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jan 29, 2024 at 01:46:45PM +0100, David Hildenbrand wrote: > Let's prepare for further changes. > > Reviewed-by: Ryan Roberts > Signed-off-by: David Hildenbrand Reviewed-by: Mike Rapoport (IBM) > --- > mm/memory.c | 63 ++++++++++++++++++++++++++++------------------------- > 1 file changed, 33 insertions(+), 30 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index 8d14ba440929..a3bdb25f4c8d 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -930,6 +930,29 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma > return 0; > } > > +static inline void __copy_present_pte(struct vm_area_struct *dst_vma, > + struct vm_area_struct *src_vma, pte_t *dst_pte, pte_t *src_pte, > + pte_t pte, unsigned long addr) > +{ > + struct mm_struct *src_mm = src_vma->vm_mm; > + > + /* If it's a COW mapping, write protect it both processes. */ > + if (is_cow_mapping(src_vma->vm_flags) && pte_write(pte)) { > + ptep_set_wrprotect(src_mm, addr, src_pte); > + pte = pte_wrprotect(pte); > + } > + > + /* If it's a shared mapping, mark it clean in the child. */ > + if (src_vma->vm_flags & VM_SHARED) > + pte = pte_mkclean(pte); > + pte = pte_mkold(pte); > + > + if (!userfaultfd_wp(dst_vma)) > + pte = pte_clear_uffd_wp(pte); > + > + set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte); > +} > + > /* > * Copy one pte. Returns 0 if succeeded, or -EAGAIN if one preallocated page > * is required to copy this pte. > @@ -939,23 +962,23 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, > pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss, > struct folio **prealloc) > { > - struct mm_struct *src_mm = src_vma->vm_mm; > - unsigned long vm_flags = src_vma->vm_flags; > pte_t pte = ptep_get(src_pte); > struct page *page; > struct folio *folio; > > page = vm_normal_page(src_vma, addr, pte); > - if (page) > - folio = page_folio(page); > - if (page && folio_test_anon(folio)) { > + if (unlikely(!page)) > + goto copy_pte; > + > + folio = page_folio(page); > + folio_get(folio); > + if (folio_test_anon(folio)) { > /* > * If this page may have been pinned by the parent process, > * copy the page immediately for the child so that we'll always > * guarantee the pinned page won't be randomly replaced in the > * future. > */ > - folio_get(folio); > if (unlikely(folio_try_dup_anon_rmap_pte(folio, page, src_vma))) { > /* Page may be pinned, we have to copy. */ > folio_put(folio); > @@ -963,34 +986,14 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, > addr, rss, prealloc, page); > } > rss[MM_ANONPAGES]++; > - } else if (page) { > - folio_get(folio); > + VM_WARN_ON_FOLIO(PageAnonExclusive(page), folio); > + } else { > folio_dup_file_rmap_pte(folio, page); > rss[mm_counter_file(folio)]++; > } > > - /* > - * If it's a COW mapping, write protect it both > - * in the parent and the child > - */ > - if (is_cow_mapping(vm_flags) && pte_write(pte)) { > - ptep_set_wrprotect(src_mm, addr, src_pte); > - pte = pte_wrprotect(pte); > - } > - VM_BUG_ON(page && folio_test_anon(folio) && PageAnonExclusive(page)); > - > - /* > - * If it's a shared mapping, mark it clean in > - * the child > - */ > - if (vm_flags & VM_SHARED) > - pte = pte_mkclean(pte); > - pte = pte_mkold(pte); > - > - if (!userfaultfd_wp(dst_vma)) > - pte = pte_clear_uffd_wp(pte); > - > - set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte); > +copy_pte: > + __copy_present_pte(dst_vma, src_vma, dst_pte, src_pte, pte, addr); > return 0; > } > > -- > 2.43.0 > > -- Sincerely yours, Mike.