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 E204CC432C0 for ; Mon, 25 Nov 2019 05:07:10 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5CF8120722 for ; Mon, 25 Nov 2019 05:07:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CF8120722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 47Lw4r2FpSzDqDf for ; Mon, 25 Nov 2019 16:07:08 +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=anshuman.khandual@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 47LvCL2M3BzDqQm for ; Mon, 25 Nov 2019 15:27:40 +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 948E431B; Sun, 24 Nov 2019 20:27:36 -0800 (PST) Received: from [192.168.0.10] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 03E013F6C4; Sun, 24 Nov 2019 20:27:21 -0800 (PST) From: Anshuman Khandual Subject: Re: [PATCH V10] mm/debug: Add tests validating architecture page table helpers To: linux-mm@kvack.org References: <1574227906-20550-1-git-send-email-anshuman.khandual@arm.com> Message-ID: Date: Mon, 25 Nov 2019 09:58:06 +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: <1574227906-20550-1-git-send-email-anshuman.khandual@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US 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: Mark Rutland , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , James Hogan , Heiko Carstens , Michal Hocko , Dave Hansen , Paul Mackerras , sparclinux@vger.kernel.org, Thomas Gleixner , linux-s390@vger.kernel.org, Jason Gunthorpe , x86@kernel.org, Russell King - ARM Linux , Matthew Wilcox , Steven Price , Tetsuo Handa , Gerald Schaefer , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Ingo Molnar , Kees Cook , Masahiro Yamada , Mark Brown , "Kirill A . Shutemov" , Dan Williams , Vlastimil Babka , Sri Krishna chowdary , Ard Biesheuvel , Greg Kroah-Hartman , linux-mips@vger.kernel.org, Ralf Baechle , linux-kernel@vger.kernel.org, Paul Burton , Mike Rapoport , Vineet Gupta , Martin Schwidefsky , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 11/20/2019 11:01 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 > Reviewed-by: Ingo Molnar > 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-20191108). > > Changes in V10: > > - Always enable DEBUG_VM_PGTABLE when DEBUG_VM is enabled per Ingo > - Added tags from Ingo Hello Andrew, There has not been any further comments on the previous version (V9) or this version (V10) of the patch which accommodated a comment from Ingo Molnar regarding making DEBUG_VM_PGTABLE always enabled when DEBUG_VM is selected. If this version looks okay, then would you please consider merging ? But if there is anything which still needs to be improved, please do let me know. I will try to incorporate that. Thank you. - Anshuman