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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 C9D1CC31E40 for ; Fri, 9 Aug 2019 10:35:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 9B2FA208C3 for ; Fri, 9 Aug 2019 10:35:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="d/26Z0VK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B2FA208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=bjiuKrTO2PxLaPtZrvNE0xNGe4wOT5quTnqu3OyDCN8=; b=d/26Z0VKso4P2L EwruXm/2GsIrMFVNOQaRmg7P35LbepXQqa7x3k4elZi8PCraoLkmyjQePrDbvmPBLAh3QD9qBnSt2 ywXEqMQc5ZK6Zbjlbmruu/eCBD7162wQSqJsnCOznr7RkcFt/etz+dfml03yjO6X5u9lgOAAXBT/v 1olL79kk8NiBkCATVx91lJGzGTAbipz9kNu/QcQIGWvMA0q3J0iIwlrAIy0vzm3sMkIyxTqHN0PSg smZeKh3Ynxjaj0+hZSMJYTm5Kk3SCn44+6D1e19EQMop/oHzmwEjdRNDv8D2evSQlZwnmhtc47Aa7 odzt7CDRf9iaqb3aPvkQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hw2FD-0004si-Ee; Fri, 09 Aug 2019 10:35:35 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hw2F9-0004rz-9k; Fri, 09 Aug 2019 10:35:32 +0000 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 0ABCD1596; Fri, 9 Aug 2019 03:35:30 -0700 (PDT) Received: from [10.163.1.243] (unknown [10.163.1.243]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 31FBE3F575; Fri, 9 Aug 2019 03:35:11 -0700 (PDT) Subject: Re: [RFC V2 0/1] mm/debug: Add tests for architecture exported page table helpers To: Matthew Wilcox References: <1565335998-22553-1-git-send-email-anshuman.khandual@arm.com> <20190809101632.GM5482@bombadil.infradead.org> From: Anshuman Khandual Message-ID: Date: Fri, 9 Aug 2019 16:05:07 +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: <20190809101632.GM5482@bombadil.infradead.org> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190809_033531_382367_933F469F X-CRM114-Status: GOOD ( 14.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: 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 , Tetsuo Handa , Heiko Carstens , Michal Hocko , linux-mm@kvack.org, Dave Hansen , Paul Mackerras , sparclinux@vger.kernel.org, Thomas Gleixner , linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Russell King - ARM Linux , Steven Price , Jason Gunthorpe , linux-arm-kernel@lists.infradead.org, linux-snps-arc@lists.infradead.org, Kees Cook , Masahiro Yamada , Mark Brown , 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" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 08/09/2019 03:46 PM, Matthew Wilcox wrote: > On Fri, Aug 09, 2019 at 01:03:17PM +0530, Anshuman Khandual wrote: >> Should alloc_gigantic_page() be made available as an interface for general >> use in the kernel. The test module here uses very similar implementation from >> HugeTLB to allocate a PUD aligned memory block. Similar for mm_alloc() which >> needs to be exported through a header. > > Why are you allocating memory at all instead of just using some > known-to-exist PFNs like I suggested? We needed PFN to be PUD aligned for pfn_pud() and PMD aligned for mk_pmd(). Now walking the kernel page table for a known symbol like kernel_init() as you had suggested earlier we might encounter page table page entries at PMD and PUD which might not be PMD or PUD aligned respectively. It seemed to me that alignment requirement is applicable only for mk_pmd() and pfn_pud() which create large mappings at those levels but that requirement does not exist for page table pages pointing to next level. Is not that correct ? Or I am missing something here ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel