From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 85A4F6B0003 for ; Tue, 13 Feb 2018 20:14:36 -0500 (EST) Received: by mail-wr0-f198.google.com with SMTP id 30so11850732wrw.6 for ; Tue, 13 Feb 2018 17:14:36 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id p26si5660415wmc.40.2018.02.13.17.14.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 13 Feb 2018 17:14:35 -0800 (PST) Date: Tue, 13 Feb 2018 17:14:32 -0800 From: Andrew Morton Subject: Re: [patch 1/2] mm, page_alloc: extend kernelcore and movablecore for percent Message-Id: <20180213171432.13c496c6603255bff66ce826@linux-foundation.org> In-Reply-To: References: <20180213154607.f631e2e033f42c32925e3d2d@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Jonathan Corbet , Vlastimil Babka , Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org On Tue, 13 Feb 2018 15:55:11 -0800 (PST) David Rientjes wrote: > > > > 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. > > > > They still have the (current) ability to define the exact amount of bytes > down to page sized granularity, whereas 1% would yield 40GB on a 4TB > system. I'm not sure that people will want any finer-grained control if > defining the proportion of the system for kernelcore. They do have the > ability with the existing interface, though, if they want to be that > precise. > > (This is a cop out for not implementing some fractional percentage parser, > although that would be possible as a more complete solution.) And the interface which you've proposed can be seamlessly extended to accept 0.07%, so not a problem. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org