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=-5.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 CC897C282DF for ; Fri, 19 Apr 2019 20:09:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91B0F2171F for ; Fri, 19 Apr 2019 20:09:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="GdJtsS0U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727678AbfDSUJA (ORCPT ); Fri, 19 Apr 2019 16:09:00 -0400 Received: from mout.gmx.net ([212.227.17.22]:60517 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726187AbfDSUJA (ORCPT ); Fri, 19 Apr 2019 16:09:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1555704514; bh=88SiZFmmhRwC/7md4AJCYpTZ6Fy7rhwLCXuvvhMnM9Y=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=GdJtsS0UYIdRetD0I+Ks7DHl8xnBOlwqtuowppXDb6B2ENY0zLllx0v8+tTLq+p62 791u5+655xbJiXK6ZbIz5QIXDeU0VCT8AW27OOoRWkEbiYXipbWGgzHAiaMAcT3PF2 wWPl2OlHZRo6VrWiBvD4jIJrO4Iw2WpwkREzaO9I= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [192.168.20.60] ([92.116.171.44]) by mail.gmx.com (mrgmx103 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MegeC-1hSeYE2YSO-00ODox; Fri, 19 Apr 2019 22:08:34 +0200 Subject: Re: DISCONTIGMEM is deprecated To: Mel Gorman , Matthew Wilcox Cc: Andrew Morton , Mikulas Patocka , James Bottomley , linux-parisc@vger.kernel.org, linux-mm@kvack.org, Vlastimil Babka , LKML , linux-arch@vger.kernel.org References: <20190419094335.GJ18914@techsingularity.net> <20190419140521.GI7751@bombadil.infradead.org> <20190419142835.GM18914@techsingularity.net> From: Helge Deller Openpgp: preference=signencrypt Autocrypt: addr=deller@gmx.de; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190419142835.GM18914@techsingularity.net> Content-Type: text/plain; charset=iso-8859-15 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:jKfNtqE87ol8fRdlT+ZrUKs8u0n6+ekTNyxZxTDCtgZi2UD62Tv Rge/xKNfkt/iueczYZ7jrnjYQUepkQb2HETqx08NAQ2QPH86oI3sEyK+N0Gt8RuE+Rez3r/ zEe/t3RoTsBjJ2jpG6uKco3FJo1xq39dq2SSz8qeDryfvNa8IZFDty6EYWwuV44zcfPS/w5 NTK2sl4yXNzb/2Ekt5oqg== X-UI-Out-Filterresults: notjunk:1;V03:K0:LRTwxRmzW7s=:5glimZF4c8lHgNpScIYCI9 Gbes011K3KCpwakv6dhniWP2sx3+xvziqzK6FoR+JZ6BRGkXR4cJ4CSJN9skvADwKTgO5Sgf0 H1wkQ9ER998YXXi7szaPKd+AmTVVcbR5Y0TqptLkpjqaVepXQorlKucp49ecxpq9bZkdL69iU ScJzkXdqK0LhXveRfcru1BQroznrDxFBzW2441omFSjo1FJ2GnDl158277HmUs4h5QzvOrHKT F9GRvtxLY7em+iTFt5XsQqGkvRx2eGwXEYMc3zirDNg/UGqeMG4IAc2Hd0ZasVorrjf/iVFMh 5LpkkiF1OIZhCjNetlX/JENDZ4TQZ0YF0eb7779qPm5vWszVCgKTIuZnLmra5gQAO5s2+Gjto suK9y9sfJ9kvFhAAkf48Hn4xh/KIvRJDLQQSvGaOfy6ZX30ztVCCv37Vc2LcYnlxQYdkBL0xT ioOGmDUI6ESuuDDdG8/w7uTpU0Meof2QhCk26vpoLtDM1hTX0t9wgvJ9vGSrHJZ3qNkpwgZbW NU+Jh6uSzsM3SHoOlbWrY/mkk9s3on5zJ1TkModulCkDoBTh1HfEcUnehMbr7EBsNzkTL8l1J zWi5cUQJ06v/KD2nw9WdGC3DXBk5wRHg8wgiDkMsDBOczHyPvfbZdFRLxIWEcbl5rMTXnlNiP Vv5TKYgitStB2ssc3NRatRDwM8n2ysCTrECIK5ekyCDI7fVPwEm2KLPnqelMWhlEQjmsvw0go agQg1/X2m+f2cSrSqQsykoivlHYQAcxMiSbsgVVMVSBTvrZJpcDYuZOLmDQiRDfVP7Z797BUQ ifdaD4mSj6VCW0kg1ZE5rfr7AHPc68BmuCo0TUCVvo76lLE/qKkRgaM7TSNXNAeAvpz88NIq9 MdKedSTytSFnPO1vCIi9k0zeOTlkdeTjXuFYt+OywWi4mTn2IH4WLxrrrXAwdQ Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On 19.04.19 16:28, Mel Gorman wrote: > On Fri, Apr 19, 2019 at 07:05:21AM -0700, Matthew Wilcox wrote: >> On Fri, Apr 19, 2019 at 10:43:35AM +0100, Mel Gorman wrote: >>> DISCONTIG is essentially deprecated and even parisc plans to move to >>> SPARSEMEM so there is no need to be fancy, this patch simply disables >>> watermark boosting by default on DISCONTIGMEM. >> >> I don't think parisc is the only arch which uses DISCONTIGMEM for !NUMA >> scenarios. Grepping the arch/ directories shows: >> >> alpha (does support NUMA, but also non-NUMA DISCONTIGMEM) >> arc (for supporting more than 1GB of memory) >> ia64 (looks complicated ...) >> m68k (for multiple chunks of memory) >> mips (does support NUMA but also non-NUMA) >> parisc (both NUMA and non-NUMA) >> >> I'm not sure that these architecture maintainers even know that DISCONT= IGMEM >> is deprecated. Adding linux-arch to the cc. > > Poor wording then -- yes, DISCONTIGMEM is still used but look where it's > used. I find it impossible to believe that any new arch would support > DISCONTIGMEM or that DISCONTIGMEM would be selected when SPARSEMEM is > available.`It's even more insane when you consider that SPARSEMEM can be > extended to support VMEMMAP so that it has similar overhead to FLATMEM > when mapping pfns to struct pages and vice-versa. FYI, on parisc we will switch from DISCONTIGMEM to SPARSEMEM with kernel 5= .2. The patch was quite simple and it's currently in the for-next tree: https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/co= mmit/?h=3Dfor-next&id=3D281b718721a5e78288271d632731cea9697749f7 Helge