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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 3786AC5DF60 for ; Tue, 5 Nov 2019 20:35:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7B95217F5 for ; Tue, 5 Nov 2019 20:35:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729727AbfKEUfD (ORCPT ); Tue, 5 Nov 2019 15:35:03 -0500 Received: from foss.arm.com ([217.140.110.172]:60270 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725806AbfKEUe5 (ORCPT ); Tue, 5 Nov 2019 15:34:57 -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 7F2DD8E6; Tue, 5 Nov 2019 12:34:56 -0800 (PST) Received: from [192.168.225.149] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 178C53F95D; Mon, 4 Nov 2019 16:00:07 -0800 (PST) Subject: Re: [PATCH V8] mm/debug: Add tests validating architecture page table helpers To: linux-mm@kvack.org, Andrew Morton Cc: 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, Michal Hocko , Matthew Wilcox References: <1572240562-23630-1-git-send-email-anshuman.khandual@arm.com> From: Anshuman Khandual Message-ID: Date: Tue, 5 Nov 2019 05:30:41 +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: <1572240562-23630-1-git-send-email-anshuman.khandual@arm.com> 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 10/28/2019 10:59 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. > > Cc: Andrew Morton > Cc: Vlastimil Babka > Cc: Greg Kroah-Hartman > Cc: Thomas Gleixner > Cc: Mike Rapoport > Cc: Jason Gunthorpe > Cc: Dan Williams > Cc: Peter Zijlstra > Cc: Michal Hocko > Cc: Mark Rutland > Cc: Mark Brown > Cc: Steven Price > Cc: Ard Biesheuvel > Cc: Masahiro Yamada > Cc: Kees Cook > Cc: Tetsuo Handa > Cc: Matthew Wilcox > Cc: Sri Krishna chowdary > Cc: Dave Hansen > Cc: Russell King - ARM Linux > Cc: Michael Ellerman > Cc: Paul Mackerras > Cc: Martin Schwidefsky > Cc: Heiko Carstens > Cc: "David S. Miller" > Cc: Vineet Gupta > Cc: James Hogan > Cc: Paul Burton > Cc: Ralf Baechle > Cc: Kirill A. Shutemov > Cc: Gerald Schaefer > Cc: Christophe Leroy > Cc: Ingo Molnar > Cc: linux-snps-arc@lists.infradead.org > Cc: linux-mips@vger.kernel.org > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-ia64@vger.kernel.org > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-s390@vger.kernel.org > Cc: linux-sh@vger.kernel.org > Cc: sparclinux@vger.kernel.org > Cc: x86@kernel.org > Cc: linux-kernel@vger.kernel.org > > Tested-by: Christophe Leroy #PPC32 > Suggested-by: Catalin Marinas > Signed-off-by: Andrew Morton > Signed-off-by: Christophe Leroy > Signed-off-by: Anshuman Khandual > --- > > This adds a test validation for architecture exported page table helpers. > Patch adds basic transformation tests at various levels of the page table. > > This test was originally suggested by Catalin during arm64 THP migration > RFC discussion earlier. Going forward it can include more specific tests > with respect to various generic MM functions like THP, HugeTLB etc and > platform specific tests. > > https://lore.kernel.org/linux-mm/20190628102003.GA56463@arrakis.emea.arm.com/ > > Needs to be applied on linux-next (next-20191025). > > Changes in V8: > > - Enabled ARCH_HAS_DEBUG_VM_PGTABLE on PPC32 platform per Christophe > - Updated feature documentation as DEBUG_VM_PGTABLE is now enabled on PPC32 platform > - Moved ARCH_HAS_DEBUG_VM_PGTABLE earlier to indent it with DEBUG_VM per Christophe > - Added an information message in debug_vm_pgtable() per Christophe > - Dropped random_vaddr boundary condition checks per Christophe and Qian > - Replaced virt_addr_valid() check with pfn_valid() check in debug_vm_pgtable() Hello Andrew, Just wondering if this version looks okay or is there anything else which still needs to be accommodated here first, before this test can be considered for merging ? Thank you. - Anshuman