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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 59972C31E59 for ; Mon, 17 Jun 2019 11:01:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0568F208E4 for ; Mon, 17 Jun 2019 11:01:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0568F208E4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6FF468E0004; Mon, 17 Jun 2019 07:01:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 688C38E0001; Mon, 17 Jun 2019 07:01:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 550BD8E0004; Mon, 17 Jun 2019 07:01:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) by kanga.kvack.org (Postfix) with ESMTP id 1B9D58E0001 for ; Mon, 17 Jun 2019 07:01:45 -0400 (EDT) Received: by mail-pl1-f198.google.com with SMTP id t2so5799508plo.10 for ; Mon, 17 Jun 2019 04:01:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:message-id :subject:from:to:cc:date:in-reply-to:references:mime-version :content-transfer-encoding; bh=Qaf+B9Yr7ALXcLt671oylbmPh3oUBy5ZfluH2fNwOPs=; b=kPEcL3VfSk9NboXxC1PFR+RipFmzmJYOnut26R9aHHJABt9ZuzVZ+b5yrTw5M8XU/n 08lFWmxhi1GUeaybGZcfEtFU6ORE0YpkV0jEVDO6YcJtwHmITWdCi4A44K3ctNtU62Tw s1kmTG7Q6/oG5e29htblYI2SeZq5+N5RRPFwFaguqyjy7aQTyHV9jVJ9lwuarpCkxv5w 9NJUqd8MV75O7ZW+KeBN9TRs2TWtJc7NxoOfHv9Q1JcSemz/5jF7hv84ORdfYBOG8w6H K2p/ZDTtHCGjD+xqHct5Pq2O9vp2h3o3oGuZWi/RnFv9G6sY6RKRUNs4fSw9B8lv87z7 O0Jw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of kai.huang@linux.intel.com designates 192.55.52.136 as permitted sender) smtp.mailfrom=kai.huang@linux.intel.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: APjAAAXX6/tJiSFrQ3+8DHjNnwa3b1o8O5emMGTPmJHMNv6l76G3+Apf Yugt2+G08aTLLB0/HCpvHqnDGmD4GBBk6ecs9T4TO9DMSKJU0cNkCIWYzRR3HY6PuocXTcDiZ5r eTVHvppTEU/ohrEiEl236NvlkoP1o7eJVoj1Kef9W9gEneQIYwk8qeXDfaO+s6KwI7w== X-Received: by 2002:a17:902:4a:: with SMTP id 68mr107918542pla.235.1560769304705; Mon, 17 Jun 2019 04:01:44 -0700 (PDT) X-Google-Smtp-Source: APXvYqz2kguIAL6mZwPwsweC3SsjpOuuzgJrgWjURU55+SBjNoxlIuY07rvYAtrrST3tKyBK/b2b X-Received: by 2002:a17:902:4a:: with SMTP id 68mr107918481pla.235.1560769303876; Mon, 17 Jun 2019 04:01:43 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1560769303; cv=none; d=google.com; s=arc-20160816; b=ta/+62qjCcE6HdNRz2b7RAyxwkN45WF5NtAw+c5H5Oi7kFi8WNSE2i++KbQKxG5gP1 0h1eU/v2BFMb9T1u3ud6UHI+AP/8hah+lFWXTpNqHksuIwqFIh313KxMDDnOXRXgRCQD eBWuRJ1u9doTjusJzO3itWgEgTDsLpAZPCuiGrDnlqI2lgjMxMSf2SZvSReChsImyhub nRjM2MA4gQJ+5hxkYM4NCPS7D4cfLpbVw8J8gS/fH3pC3IEXZ5QDRS9q4fI4WHgrci92 ApVnGVTs7GpiWlgyxxndzi6r5+9iLNDjcNWaUEkKQEKcSlBE416FOJRsKNcbHDrWSHZr kJoA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to:date :cc:to:from:subject:message-id; bh=Qaf+B9Yr7ALXcLt671oylbmPh3oUBy5ZfluH2fNwOPs=; b=hkUbhTuUbddOZDyPp1WkqU92pSUOub1BKt9x1yJnpsHz++eR8ov7yXq/40jy+gbw5y 0ghByJHH1Wrwne/gugSSRJFsYSJK30LXLwS9uTKtapz+ywidAWrvyW4HhLOdFKuI3/kC BTT6zUCcr+M7l2+bWr0cyGM80Afw5WcHXIq6XvyQxez6iD6T/AtPGqBiydap6FrPZ3Dd c/fdM/KhzuB2BojMeF4XazkfR5kruOi6Vz8URq155absxaN84nrf6gQcu5Yp514J1dnK zSJbXLuh8xhdIVh4jivI7i+Y6MhxdHWPHUKCa9WELYMpqvH9cIeWRtDUVdm9kypYyKVy WmGA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of kai.huang@linux.intel.com designates 192.55.52.136 as permitted sender) smtp.mailfrom=kai.huang@linux.intel.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga12.intel.com (mga12.intel.com. [192.55.52.136]) by mx.google.com with ESMTPS id z8si9602367pjn.51.2019.06.17.04.01.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 17 Jun 2019 04:01:43 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of kai.huang@linux.intel.com designates 192.55.52.136 as permitted sender) client-ip=192.55.52.136; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of kai.huang@linux.intel.com designates 192.55.52.136 as permitted sender) smtp.mailfrom=kai.huang@linux.intel.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jun 2019 04:01:43 -0700 X-ExtLoop1: 1 Received: from khuang2-desk.gar.corp.intel.com ([10.255.91.82]) by fmsmga006.fm.intel.com with ESMTP; 17 Jun 2019 04:01:39 -0700 Message-ID: <1560769298.5187.16.camel@linux.intel.com> Subject: Re: [PATCH, RFC 20/62] mm/page_ext: Export lookup_page_ext() symbol From: Kai Huang To: Peter Zijlstra , "Kirill A. Shutemov" Cc: "Kirill A. Shutemov" , Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Andy Lutomirski , David Howells , Kees Cook , Dave Hansen , Jacob Pan , Alison Schofield , linux-mm@kvack.org, kvm@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 17 Jun 2019 23:01:38 +1200 In-Reply-To: <20190617093054.GB3419@hirez.programming.kicks-ass.net> References: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> <20190508144422.13171-21-kirill.shutemov@linux.intel.com> <20190614111259.GA3436@hirez.programming.kicks-ass.net> <20190614224443.qmqolaigu5wnf75p@box> <20190617093054.GB3419@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.24.6 (3.24.6-1.fc26) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit 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: On Mon, 2019-06-17 at 11:30 +0200, Peter Zijlstra wrote: > On Sat, Jun 15, 2019 at 01:44:43AM +0300, Kirill A. Shutemov wrote: > > On Fri, Jun 14, 2019 at 01:12:59PM +0200, Peter Zijlstra wrote: > > > On Wed, May 08, 2019 at 05:43:40PM +0300, Kirill A. Shutemov wrote: > > > > page_keyid() is inline funcation that uses lookup_page_ext(). KVM is > > > > going to use page_keyid() and since KVM can be built as a module > > > > lookup_page_ext() has to be exported. > > > > > > I _really_ hate having to export world+dog for KVM. This one might not > > > be a real issue, but I itch every time I see an export for KVM these > > > days. > > > > Is there any better way? Do we need to invent EXPORT_SYMBOL_KVM()? :P > > Or disallow KVM (or parts thereof) from being a module anymore. For this particular symbol expose, I don't think its fair to blame KVM since the fundamental reason is because page_keyid() (which calls lookup_page_ext()) being implemented as static inline function in header file, so essentially having any other module who calls page_keyid() will trigger this problem -- in fact IOMMU driver calls page_keyid() too so even w/o KVM lookup_page_ext() needs to be exposed. Thanks, -Kai