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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 C8040CA9EBB for ; Mon, 4 Nov 2019 02:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99DC22190F for ; Mon, 4 Nov 2019 02:15:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728355AbfKDCPl (ORCPT ); Sun, 3 Nov 2019 21:15:41 -0500 Received: from foss.arm.com ([217.140.110.172]:34396 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728227AbfKDCPk (ORCPT ); Sun, 3 Nov 2019 21:15:40 -0500 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 E7F6631F; Sun, 3 Nov 2019 18:15:39 -0800 (PST) Received: from [10.163.1.23] (unknown [10.163.1.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6E4893F67D; Sun, 3 Nov 2019 18:15:22 -0800 (PST) Subject: Re: [PATCH V8] mm/debug: Add tests validating architecture page table helpers To: Qian Cai Cc: linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Greg Kroah-Hartman , Thomas Gleixner , Mike Rapoport , Jason Gunthorpe , Dan Williams , Peter Zijlstra , Michal Hocko , Mark Rutland , Mark Brown , Steven Price , Ard Biesheuvel , Masahiro Yamada , Kees Cook , Tetsuo Handa , Matthew Wilcox , Sri Krishna chowdary , Dave Hansen , Russell King - ARM Linux , Michael Ellerman , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , "David S. Miller" , Vineet Gupta , James Hogan , Paul Burton , Ralf Baechle , "Kirill A . Shutemov" , Gerald Schaefer , Christophe Leroy , Ingo Molnar , linux-snps-arc@lists.infradead.org, linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org References: <1572240562-23630-1-git-send-email-anshuman.khandual@arm.com> From: Anshuman Khandual Message-ID: Date: Mon, 4 Nov 2019 07:45:56 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On 10/29/2019 04:01 PM, Qian Cai wrote: > > >> On Oct 28, 2019, at 1:29 AM, Anshuman Khandual wrote: >> >> This adds tests which will validate architecture page table helpers and >> other accessors in their compliance with expected generic MM semantics. >> This will help various architectures in validating changes to existing >> page table helpers or addition of new ones. >> >> This test covers basic page table entry transformations including but not >> limited to old, young, dirty, clean, write, write protect etc at various >> level along with populating intermediate entries with next page table page >> and validating them. >> >> Test page table pages are allocated from system memory with required size >> and alignments. The mapped pfns at page table levels are derived from a >> real pfn representing a valid kernel text symbol. This test gets called >> right after page_alloc_init_late(). >> >> This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with >> CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to >> select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and >> arm64. Going forward, other architectures too can enable this after fixing >> build or runtime problems (if any) with their page table helpers. >> >> Folks interested in making sure that a given platform's page table helpers >> conform to expected generic MM semantics should enable the above config >> which will just trigger this test during boot. Any non conformity here will >> be reported as an warning which would need to be fixed. This test will help >> catch any changes to the agreed upon semantics expected from generic MM and >> enable platforms to accommodate it thereafter. > > This looks like a perfect candidate to streamline with the new kunit framework, no? I have not been following the kunit test framework. But being highly dependent on existing MM accessors (generic or platform) and very much page table modification centric, mm/ is the best place for this test IMHO. It is now also part of DEBUG_VM set of tests. Probably in future all existing MM tests (mm/ or lib/) might move to kunit framework but for now it should remain with DEBUG_VM set of tests.