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=-1.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 E6FE6C43387 for ; Tue, 15 Jan 2019 15:53:25 +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 B8D6620645 for ; Tue, 15 Jan 2019 15:53:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sLU9nZoq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8D6620645 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=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=hPMJrWT2oNKhFcqqwS3hMO4ebrrYxJTq3uYjCV/tvhQ=; b=sLU9nZoqaShOdf lTDsddkQ3Es9mp7gRUlBKK5a5Wr/QvMTEjha3YqUR24SrFIdYwAsgjXVPEOh01NO6Y1g0bb959+OA Uwy21N47dRVm/XkITzFj5iaV6b7PhmW7q/0F4X2fXgopfU4NnHQKNJQuWoZ7SS/Dk0cOTxXi/W0p9 7+gwaMiryfvPEYVTUo37Xazh7aMz7UVbMjvvRBI6itNES+lHE1sP/Z32b1X/7kJ4xLP0jVWdzOys5 ngTBbXeAwl9aMEvUSDy3p0cHS8OQi/sPTJbsrXPynnYEM7Dv+viajYj4v0zmTYUCnWidiLcCQIf8R T+qJDclWorMRySxbgUrA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gjR1o-0003QD-6M; Tue, 15 Jan 2019 15:53:24 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gjR1k-0003PL-JU; Tue, 15 Jan 2019 15:53:21 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4307ED3C0F; Tue, 15 Jan 2019 15:53:17 +0000 (UTC) Received: from [10.36.116.79] (ovpn-116-79.ams2.redhat.com [10.36.116.79]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2DF7B5C234; Tue, 15 Jan 2019 15:53:00 +0000 (UTC) Subject: Re: [PATCH v2 0/9] mm: PG_reserved cleanups and documentation To: Christoph Hellwig References: <20190114125903.24845-1-david@redhat.com> <20190115153839.GE26443@infradead.org> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <447946ff-403a-6ca3-2958-688d28a82fce@redhat.com> Date: Tue, 15 Jan 2019 16:53:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20190115153839.GE26443@infradead.org> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 15 Jan 2019 15:53:18 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190115_075320_686519_B145E9F8 X-CRM114-Status: GOOD ( 20.66 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Michal Hocko , CHANDAN VN , David Airlie , Benjamin Herrenschmidt , Bhupesh Sharma , Palmer Dabbelt , Heiko Carstens , Stefan Agner , Michal Hocko , David Howells , linux-mm@kvack.org, Paul Mackerras , linux-riscv@lists.infradead.org, Alexander Duyck , linux-s390@vger.kernel.org, Florian Fainelli , Arnd Bergmann , Michael Ellerman , Pavel Tatashin , Matthew Wilcox , AKASHI Takahiro , Geert Uytterhoeven , Matthias Brugger , Catalin Marinas , Anthony Yznaga , Tobias Klauser , Laura Abbott , Fenghua Yu , Albert Ou , Kees Cook , Vasily Gorbik , Stephen Rothwell , Marc Zyngier , Will Deacon , linuxppc-dev@lists.ozlabs.org, Kristina Martsenko , linux-m68k@lists.linux-m68k.org, Dave Kleikamp , linux-mediatek@lists.infradead.org, Dan Williams , linux-arm-kernel@lists.infradead.org, Christophe Leroy , Tony Luck , Greg Kroah-Hartman , Randy Dunlap , Oleg Nesterov , linux-kernel@vger.kernel.org, Miles Chen , Mike Rapoport , James Morse , Souptick Joarder , Johannes Weiner , Martin Schwidefsky , Andrew Morton , Logan Gunthorpe , Greg Hackmann Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org On 15.01.19 16:38, Christoph Hellwig wrote: > On Mon, Jan 14, 2019 at 01:58:54PM +0100, David Hildenbrand wrote: >> Nothing major changed since the last version. I would be happy about >> additional ACKs. If there are no further comments, can this go via the >> mm-tree in one chunk? >> >> I was recently going over all users of PG_reserved. Short story: it is >> difficult and sometimes not really clear if setting/checking for >> PG_reserved is only a relict from the past. Easy to break things. I >> guess I now have a pretty good idea wh things are like that >> nowadays and how they evolved. > > Any reason you skipped > > drivers/gpu/drm/drm_pci.c:drm_pci_alloc() > > and > > drivers/gpu/drm/drm_scatter.c:drm_legacy_sg_alloc() > > which both look completely bogus as-is? > > In fact we should probably just try to kill them off as they have > very few users left. > I actually have patches lying around for these, however excluded them for now as I was not 100% sure about the implications ("Easy to break things"). Are you sure nobody in the system (especially somebody who does a PageReserved()) relies on this to identify e.g. MMIO pages? (e.g. ioremap on some archs, KVM code) (I am by far no DRM expert, but when I hear DMA, I tend to be careful) -- Thanks, David / dhildenb _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by kanga.kvack.org (Postfix) with ESMTP id 93EFF8E0002 for ; Tue, 15 Jan 2019 10:53:20 -0500 (EST) Received: by mail-qt1-f198.google.com with SMTP id 41so2688294qto.17 for ; Tue, 15 Jan 2019 07:53:20 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id j25si6516431qtn.303.2019.01.15.07.53.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Jan 2019 07:53:19 -0800 (PST) Subject: Re: [PATCH v2 0/9] mm: PG_reserved cleanups and documentation References: <20190114125903.24845-1-david@redhat.com> <20190115153839.GE26443@infradead.org> From: David Hildenbrand Message-ID: <447946ff-403a-6ca3-2958-688d28a82fce@redhat.com> Date: Tue, 15 Jan 2019 16:53:00 +0100 MIME-Version: 1.0 In-Reply-To: <20190115153839.GE26443@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: linux-mm@kvack.org, Mark Rutland , Michal Hocko , CHANDAN VN , David Airlie , Benjamin Herrenschmidt , Bhupesh Sharma , Palmer Dabbelt , Heiko Carstens , Tony Luck , Stefan Agner , Michal Hocko , David Howells , Paul Mackerras , Michael Ellerman , linux-riscv@lists.infradead.org, Alexander Duyck , linux-s390@vger.kernel.org, Florian Fainelli , Vasily Gorbik , Logan Gunthorpe , Pavel Tatashin , Matthew Wilcox , AKASHI Takahiro , Geert Uytterhoeven , Catalin Marinas , Anthony Yznaga , Tobias Klauser , Laura Abbott , Fenghua Yu , Albert Ou , Kees Cook , Arnd Bergmann , Stephen Rothwell , Marc Zyngier , Will Deacon , Kristina Martsenko , linux-m68k@lists.linux-m68k.org, Dave Kleikamp , linux-mediatek@lists.infradead.org, Oleg Nesterov , Dan Williams , linux-arm-kernel@lists.infradead.org, Christophe Leroy , Matthias Brugger , Greg Kroah-Hartman , Randy Dunlap , linux-kernel@vger.kernel.org, Miles Chen , Mike Rapoport , James Morse , Souptick Joarder , Johannes Weiner , Martin Schwidefsky , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Greg Hackmann On 15.01.19 16:38, Christoph Hellwig wrote: > On Mon, Jan 14, 2019 at 01:58:54PM +0100, David Hildenbrand wrote: >> Nothing major changed since the last version. I would be happy about >> additional ACKs. If there are no further comments, can this go via the >> mm-tree in one chunk? >> >> I was recently going over all users of PG_reserved. Short story: it is >> difficult and sometimes not really clear if setting/checking for >> PG_reserved is only a relict from the past. Easy to break things. I >> guess I now have a pretty good idea wh things are like that >> nowadays and how they evolved. > > Any reason you skipped > > drivers/gpu/drm/drm_pci.c:drm_pci_alloc() > > and > > drivers/gpu/drm/drm_scatter.c:drm_legacy_sg_alloc() > > which both look completely bogus as-is? > > In fact we should probably just try to kill them off as they have > very few users left. > I actually have patches lying around for these, however excluded them for now as I was not 100% sure about the implications ("Easy to break things"). Are you sure nobody in the system (especially somebody who does a PageReserved()) relies on this to identify e.g. MMIO pages? (e.g. ioremap on some archs, KVM code) (I am by far no DRM expert, but when I hear DMA, I tend to be careful) -- Thanks, David / dhildenb 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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 21A47C43387 for ; Tue, 15 Jan 2019 15:54:59 +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 454C620645 for ; Tue, 15 Jan 2019 15:54:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 454C620645 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 43fFKC5sSgzDqQv for ; Wed, 16 Jan 2019 02:54:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=redhat.com (client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=david@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 43fFHP1lX9zDqMv for ; Wed, 16 Jan 2019 02:53:21 +1100 (AEDT) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4307ED3C0F; Tue, 15 Jan 2019 15:53:17 +0000 (UTC) Received: from [10.36.116.79] (ovpn-116-79.ams2.redhat.com [10.36.116.79]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2DF7B5C234; Tue, 15 Jan 2019 15:53:00 +0000 (UTC) Subject: Re: [PATCH v2 0/9] mm: PG_reserved cleanups and documentation To: Christoph Hellwig References: <20190114125903.24845-1-david@redhat.com> <20190115153839.GE26443@infradead.org> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <447946ff-403a-6ca3-2958-688d28a82fce@redhat.com> Date: Tue, 15 Jan 2019 16:53:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20190115153839.GE26443@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 15 Jan 2019 15:53:18 +0000 (UTC) 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 , Michal Hocko , CHANDAN VN , David Airlie , Bhupesh Sharma , Palmer Dabbelt , Heiko Carstens , Stefan Agner , Michal Hocko , David Howells , linux-mm@kvack.org, Paul Mackerras , linux-riscv@lists.infradead.org, Alexander Duyck , linux-s390@vger.kernel.org, Florian Fainelli , Arnd Bergmann , Pavel Tatashin , Matthew Wilcox , AKASHI Takahiro , Geert Uytterhoeven , Matthias Brugger , Catalin Marinas , Anthony Yznaga , Tobias Klauser , Laura Abbott , Fenghua Yu , Albert Ou , Kees Cook , Vasily Gorbik , Stephen Rothwell , Marc Zyngier , Will Deacon , linuxppc-dev@lists.ozlabs.org, Kristina Martsenko , linux-m68k@lists.linux-m68k.org, Dave Kleikamp , linux-mediatek@lists.infradead.org, Dan Williams , linux-arm-kernel@lists.infradead.org, Tony Luck , Greg Kroah-Hartman , Randy Dunlap , Oleg Nesterov , linux-kernel@vger.kernel.org, Miles Chen , Mike Rapoport , James Morse , Souptick Joarder , Johannes Weiner , Martin Schwidefsky , Andrew Morton , Logan Gunthorpe , Greg Hackmann Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 15.01.19 16:38, Christoph Hellwig wrote: > On Mon, Jan 14, 2019 at 01:58:54PM +0100, David Hildenbrand wrote: >> Nothing major changed since the last version. I would be happy about >> additional ACKs. If there are no further comments, can this go via the >> mm-tree in one chunk? >> >> I was recently going over all users of PG_reserved. Short story: it is >> difficult and sometimes not really clear if setting/checking for >> PG_reserved is only a relict from the past. Easy to break things. I >> guess I now have a pretty good idea wh things are like that >> nowadays and how they evolved. > > Any reason you skipped > > drivers/gpu/drm/drm_pci.c:drm_pci_alloc() > > and > > drivers/gpu/drm/drm_scatter.c:drm_legacy_sg_alloc() > > which both look completely bogus as-is? > > In fact we should probably just try to kill them off as they have > very few users left. > I actually have patches lying around for these, however excluded them for now as I was not 100% sure about the implications ("Easy to break things"). Are you sure nobody in the system (especially somebody who does a PageReserved()) relies on this to identify e.g. MMIO pages? (e.g. ioremap on some archs, KVM code) (I am by far no DRM expert, but when I hear DMA, I tend to be careful) -- Thanks, David / dhildenb From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH v2 0/9] mm: PG_reserved cleanups and documentation Date: Tue, 15 Jan 2019 16:53:00 +0100 Message-ID: <447946ff-403a-6ca3-2958-688d28a82fce@redhat.com> References: <20190114125903.24845-1-david@redhat.com> <20190115153839.GE26443@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190115153839.GE26443@infradead.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane.org@lists.infradead.org To: Christoph Hellwig Cc: Mark Rutland , Michal Hocko , CHANDAN VN , David Airlie , Benjamin Herrenschmidt , Bhupesh Sharma , Palmer Dabbelt , Heiko Carstens , Stefan Agner , Michal Hocko , David Howells , linux-mm@kvack.org, Paul Mackerras , linux-riscv@lists.infradead.org, Alexander Duyck , linux-s390@vger.kernel.org, Florian Fainelli , Arnd Bergmann , Michael Ellerman , Pavel Tatashin , Matthew Wilcox , AKASHI Takahiro , Geert Uytterhoeven Matthias Brugger List-Id: linux-mediatek@lists.infradead.org On 15.01.19 16:38, Christoph Hellwig wrote: > On Mon, Jan 14, 2019 at 01:58:54PM +0100, David Hildenbrand wrote: >> Nothing major changed since the last version. I would be happy about >> additional ACKs. If there are no further comments, can this go via the >> mm-tree in one chunk? >> >> I was recently going over all users of PG_reserved. Short story: it is >> difficult and sometimes not really clear if setting/checking for >> PG_reserved is only a relict from the past. Easy to break things. I >> guess I now have a pretty good idea wh things are like that >> nowadays and how they evolved. > > Any reason you skipped > > drivers/gpu/drm/drm_pci.c:drm_pci_alloc() > > and > > drivers/gpu/drm/drm_scatter.c:drm_legacy_sg_alloc() > > which both look completely bogus as-is? > > In fact we should probably just try to kill them off as they have > very few users left. > I actually have patches lying around for these, however excluded them for now as I was not 100% sure about the implications ("Easy to break things"). Are you sure nobody in the system (especially somebody who does a PageReserved()) relies on this to identify e.g. MMIO pages? (e.g. ioremap on some archs, KVM code) (I am by far no DRM expert, but when I hear DMA, I tend to be careful) -- Thanks, David / dhildenb