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=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 2A97AC2D0DB for ; Wed, 22 Jan 2020 10:42:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E9C2A2465B for ; Wed, 22 Jan 2020 10:42:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E9C2A2465B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8214B6B0007; Wed, 22 Jan 2020 05:42:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7D26C6B0008; Wed, 22 Jan 2020 05:42:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6C1726B000A; Wed, 22 Jan 2020 05:42:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0235.hostedemail.com [216.40.44.235]) by kanga.kvack.org (Postfix) with ESMTP id 571E46B0007 for ; Wed, 22 Jan 2020 05:42:34 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id EBE892C06 for ; Wed, 22 Jan 2020 10:42:33 +0000 (UTC) X-FDA: 76404931386.15.box09_6da18dbdc053d X-HE-Tag: box09_6da18dbdc053d X-Filterd-Recvd-Size: 4549 Received: from mail-wm1-f66.google.com (mail-wm1-f66.google.com [209.85.128.66]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Wed, 22 Jan 2020 10:42:33 +0000 (UTC) Received: by mail-wm1-f66.google.com with SMTP id p17so6629106wma.1 for ; Wed, 22 Jan 2020 02:42:33 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ZWrcztGPEdmdljU6rzvPLWUWlGRg7cvJpWEcVwcN7o8=; b=kx/1CGdCckS2aCOhJkg8H+crEwa/6wnZGWZneJd/FGltc/gFlpBC5LRDOhYdjazy8O FUCFsFByxX5kGuyZ7Io8vtQiUH2fTHbFhOWYDs3goNfMgNrIfoyCCFXWjGXxkzf9qOOX 88gzYACerzd5O69WgKZa5a7jce5ytETEn6wAx4OuB0gz/WY5ppm2Dast7FB5DX/V+9yE 6TGvMSbG+TdZOjAudRxC4zgpm/x2rXgRy6t0I6m+J4Dub+6XypPUwrFSFEoUDMgrBjXb C2jInWnvyseK3xFdu5bzwRnbIr9yg5jd5WNaM7ltrGhiN8AU+411A1YhpU6jW4YmAsQ2 9r7g== X-Gm-Message-State: APjAAAVOXIKAc2X/A6wg2d0W+GrO1ycNXRUPtCmUdYM7CUh97AFtFV1C gUF0ELErpDICITMJsKeECKk= X-Google-Smtp-Source: APXvYqwOXY4WlwXUfJ7If8qgml0d4AG62OZDyxS9ZDP0CGgPABYQ40tZm0CAz1TQujq4tDsEx0hzfw== X-Received: by 2002:a1c:4b01:: with SMTP id y1mr2205649wma.12.1579689752151; Wed, 22 Jan 2020 02:42:32 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id b17sm56037447wrp.49.2020.01.22.02.42.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jan 2020 02:42:31 -0800 (PST) Date: Wed, 22 Jan 2020 11:42:30 +0100 From: Michal Hocko To: David Hildenbrand Cc: Dan Williams , Linux Kernel Mailing List , Linux MM , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Greg Kroah-Hartman , "Rafael J. Wysocki" , Andrew Morton , Leonardo Bras , Nathan Lynch , Allison Randal , Nathan Fontenot , Thomas Gleixner , Stephen Rothwell , Anshuman Khandual , lantianyu1986@gmail.com, linuxppc-dev Subject: Re: [PATCH RFC v1] mm: is_mem_section_removable() overhaul Message-ID: <20200122104230.GU29276@dhcp22.suse.cz> References: <20200117145233.GB19428@dhcp22.suse.cz> <65606e2e-1cf7-de3b-10b1-33653cb41a52@redhat.com> <20200117152947.GK19428@dhcp22.suse.cz> <25a94f61-46a1-59a6-6b54-8cc6b35790d2@redhat.com> <20200120074816.GG18451@dhcp22.suse.cz> <20200121120714.GJ29276@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed 22-01-20 11:39:08, David Hildenbrand wrote: > >>> Really, the interface is flawed and should have never been merged in the > >>> first place. We cannot simply remove it altogether I am afraid so let's > >>> at least remove the bogus code and pretend that the world is a better > >>> place where everything is removable except the reality sucks... > >> > >> As I expressed already, the interface works as designed/documented and > >> has been used like that for years. > > > > It seems we do differ in the usefulness though. Using a crappy interface > > for years doesn't make it less crappy. I do realize we cannot remove the > > interface but we can remove issues with the implementation and I dare to > > say that most existing users wouldn't really notice. > > Well, at least powerpc-utils (why this interface was introduced) will > notice a) performance wise and b) because more logging output will be > generated (obviously non-offlineable blocks will be tried to offline). I would really appreciate some specific example for a real usecase. I am not familiar with powerpc-utils worklflows myself. -- Michal Hocko SUSE Labs