Received: by 10.223.185.116 with SMTP id b49csp22041wrg; Tue, 13 Feb 2018 15:47:12 -0800 (PST) X-Google-Smtp-Source: AH8x227vO3OuEM+0XhVvAo81l3GBtgg/aGqQoACaEXgOvggA6r8QZxj3zfu7+dk5LyXeZ4gYAb1X X-Received: by 2002:a17:902:d68a:: with SMTP id v10-v6mr2583643ply.206.1518565632822; Tue, 13 Feb 2018 15:47:12 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1518565632; cv=none; d=google.com; s=arc-20160816; b=ZyPCMgQThAevSHkB8BENQEv6GL1ZOP8W/XZTVTd2g06oodIIzVBqIjgRqG1i36uT41 1/tJ7nnDznwvWldA5AnkxQT1W/JJaoxHPibKhgIaReJAs7lT+BImw+4RxGkzQWdostUk RJ+I2bjmaAK33ka6EsvpU0RbrzRbXHYRqRYGaB2Fl5KniUyK32V8u1KDXgpeQXgsBzhc hU2NK853T2q4QeZAroKIhee1wZQ/JBTEJw/dXbAgDiqJQoWMG3co1HdkmMvf3UsfwZkL bXIa81V3iI/vjZzvFO6n4f9Z6TkDw8JZ4D//EgdZSEhsIX+sqlDzRySyglQ7AiooZn+2 lfoQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date :arc-authentication-results; bh=AzRgaO5NLLlv2uoPlfncU6+FkBnieTESsWBbMxJoDhA=; b=XjWqVzyicAEKevvIJgO4qiYD6zJco6qVdak38onnXC3/q5Mh1a3pbc1m89N+QqHWKo YoYW8fIFythA2jlQOwQ9lou58RFCIQJ8bo7vknzULu65xJc6ss+A8W9tuFaeami01KqL mj9sl5C9keXhOwyQj8WS7Dw2mKjRwgJFvJv40oA7q/DITn1MJ4dr0n2Jg0Q79APnI8Rc lkTmP1B4xh/jfJ/vBNi8PyQwCI9i8YDGHxJjHgv9JX9MRDNq8h4/139oQWoGmLdAp43t FEKxMKgRJj8m+EDbuKEHkqgoqy8LPsMY752Orf8JfyCQ9FfYI+l/LCCwyJLaPiKGEN+n cJhA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id a5-v6si222309plh.450.2018.02.13.15.46.57; Tue, 13 Feb 2018 15:47:12 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966141AbeBMXqL (ORCPT + 99 others); Tue, 13 Feb 2018 18:46:11 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36584 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966064AbeBMXqJ (ORCPT ); Tue, 13 Feb 2018 18:46:09 -0500 Received: from akpm3.svl.corp.google.com (unknown [104.133.9.92]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 204041083; Tue, 13 Feb 2018 23:46:09 +0000 (UTC) Date: Tue, 13 Feb 2018 15:46:07 -0800 From: Andrew Morton To: David Rientjes Cc: Jonathan Corbet , Vlastimil Babka , Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org Subject: Re: [patch 1/2] mm, page_alloc: extend kernelcore and movablecore for percent Message-Id: <20180213154607.f631e2e033f42c32925e3d2d@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 12 Feb 2018 16:24:25 -0800 (PST) David Rientjes wrote: > Both kernelcore= and movablecore= can be used to define the amount of > ZONE_NORMAL and ZONE_MOVABLE on a system, respectively. This requires > the system memory capacity to be known when specifying the command line, > however. > > This introduces the ability to define both kernelcore= and movablecore= > as a percentage of total system memory. This is convenient for systems > software that wants to define the amount of ZONE_MOVABLE, for example, as > a proportion of a system's memory rather than a hardcoded byte value. > > To define the percentage, the final character of the parameter should be > a '%'. Is this fine-grained enough? We've had percentage-based tunables in the past, and 10 years later when systems are vastly larger, 1% is too much.