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 X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E2AAC07E9B for ; Mon, 19 Jul 2021 11:34:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C1AA60FF3 for ; Mon, 19 Jul 2021 11:34:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C1AA60FF3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65B918D00F4; Mon, 19 Jul 2021 07:34:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 632718D00EC; Mon, 19 Jul 2021 07:34:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D3728D00F4; Mon, 19 Jul 2021 07:34:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0057.hostedemail.com [216.40.44.57]) by kanga.kvack.org (Postfix) with ESMTP id 2B07B8D00EC for ; Mon, 19 Jul 2021 07:34:00 -0400 (EDT) Received: from smtpin40.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B9202243A6 for ; Mon, 19 Jul 2021 11:33:58 +0000 (UTC) X-FDA: 78379128156.40.E9151DC Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf16.hostedemail.com (Postfix) with ESMTP id 4EA02F000091 for ; Mon, 19 Jul 2021 11:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626694437; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yZ/P5u++j9Qpns29fggdm0r9Q3FMuOlkVwzoX+ZoX4s=; b=LtrTGt9edGXQZPxzlTYhQLrm+RE9rxXG1X6YWULA+TSnZNqSHqZvBBnxu3Tp0cKUUPPcsF p7AH6StUY3q44aIuAeoGUl30mcr0xfI5/j+PrMhbIQLBJjc4G53QfwAEsgBblxthaUwnxU LMugnuwhmdHUOCbFgrJ8zlKKbZbFu4U= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-484-sH2EP5KoNgWIbfW8MCVQQg-1; Mon, 19 Jul 2021 07:33:56 -0400 X-MC-Unique: sH2EP5KoNgWIbfW8MCVQQg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 678C3800FF0; Mon, 19 Jul 2021 11:33:54 +0000 (UTC) Received: from [10.64.54.195] (vpn2-54-195.bne.redhat.com [10.64.54.195]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 905C119C44; Mon, 19 Jul 2021 11:33:49 +0000 (UTC) Subject: Re: [PATCH v2 00/12] mm/debug_vm_pgtable: Enhancements From: Gavin Shan To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com References: <20210719054138.198373-1-gshan@redhat.com> Message-ID: <3d0a3a3b-e0ce-bf13-c8ce-de93a6f21c2d@redhat.com> Date: Mon, 19 Jul 2021 21:34:05 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <20210719054138.198373-1-gshan@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LtrTGt9e; spf=none (imf16.hostedemail.com: domain of gshan@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=gshan@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 4EA02F000091 X-Stat-Signature: 4p6h4t3ku9cei7otw7ppmne6mzbta4n6 X-HE-Tag: 1626694438-211093 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: Hi Anshuman, On 7/19/21 3:41 PM, Gavin Shan wrote: > There are couple of issues with current implementations and this series > tries to resolve the issues: > > (a) All needed information are scattered in variables, passed to various > test functions. The code is organized in pretty much relaxed fashion. > > (b) The page isn't allocated from buddy during page table entry modifying > tests. The page can be invalid, conflicting to the implementations > of set_xxx_at() on ARM64. The target page is accessed so that the iCache > can be flushed when execution permission is given on ARM64. Besides, > the target page can be unmapped and access to it causes kernel crash. > > "struct pgtable_debug_args" is introduced to address issue (a). For issue > (b), the used page is allocated from buddy in page table entry modifying > tests. The corresponding tets will be skipped if we fail to allocate the > (huge) page. For other test cases, the original page around to kernel > symbol (@start_kernel) is still used. > > The patches are organized as below. PATCH[2-10] could be combined to one > patch, but it will make the review harder: > > PATCH[1] introduces "struct pgtable_debug_args" as place holder of all > needed information. With it, the old and new implementation > can coexist. > PATCH[2-10] uses "struct pgtable_debug_args" in various test functions. > PATCH[11] removes the old implementation. > PATCH[12] fixes the issue of corrupted page flag for ARM64 > > Changelog > ========= > v2: > * Rename struct vm_pgtable_debug to struct pgtable_debug_args. > The parameter name to various test functions are renamed > to "@args" (Anshuman) > * Code changes as suggested by Anshuman (Anshuman) > Please ignore v2. I will post v3 to fix couple of issues in v2: (1) The subjects of PATCH[5/12] and PATCH[9/12] should be fixed to start with "mm/debug_vm_pgtable". (2) "WARN_ON(!pud_none(pud))" is missed in PATCH[9/12]. Otherwise, build warning for unused variable @pud is raised. (3) Build warnings for unused variables in separate patches are raised, reported by 0-DAY CI Kernel Test Service. Thanks, Gavin > Gavin Shan (12): > mm/debug_vm_pgtable: Introduce struct pgtable_debug_args > mm/debug_vm_pgtable: Use struct pgtable_debug_args in basic tests > mm/debug_vm_pgtable: Use struct pgtable_debug_args in leaf and > savewrite tests > mm/debug_vm_pgtable: Use struct pgtable_debug_args in protnone and > devmap tests > mm/vm_debug_pgtable: Use struct pgtable_debug_args in soft_dirty and > swap tests > mm/debug_vm_pgtable: Use struct pgtable_debug_args in migration and > thp tests > mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying > tests > mm/debug_vm_pgtable: Use struct pgtable_debug_args in PMD > mm/vm_debug_pgtable: Use struct pgtable_debug_args in PUD modifying > tests > mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D > modifying tests > mm/debug_vm_pgtable: Remove unused code > mm/debug_vm_pgtable: Fix corrupted page flag > > mm/debug_vm_pgtable.c | 849 ++++++++++++++++++++++++------------------ > 1 file changed, 479 insertions(+), 370 deletions(-) >