From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752789AbdJFVab (ORCPT ); Fri, 6 Oct 2017 17:30:31 -0400 Received: from mail-qk0-f169.google.com ([209.85.220.169]:44437 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751654AbdJFVa2 (ORCPT ); Fri, 6 Oct 2017 17:30:28 -0400 X-Google-Smtp-Source: AOwi7QABiO33D15hqmjaIL0PVUOed1ZM8iXlBA4+2vqRblWKrAX7PWsWVTmbDIUej5f+AhyE/QIPqg== Date: Fri, 6 Oct 2017 17:30:25 -0400 (EDT) From: Nicolas Pitre To: Rob Herring cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Frank Rowand , Grant Likely Subject: Re: [PATCH 0/6] Shrinking DT memory usage In-Reply-To: <20171005194422.26224-1-robh@kernel.org> Message-ID: References: <20171005194422.26224-1-robh@kernel.org> User-Agent: Alpine 2.21 (LFD 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 5 Oct 2017, Rob Herring wrote: > On kernels with a minimal config and a RAM target in the 100s of KB, DT > is quite a hog of runtime memory usage. How much is dependent on how many > nodes and properties in the DT which have a corresponding struct device_node > and struct property in the kernel. Just skipping disabled nodes saves a > lot by not creating the device_nodes in the first place[1], but there's > more low hanging fruit by making some of the fields in struct property and > struct device_node optional. With the changes here, the memory usage goes > from 17KB to under 8KB on QEMU's ARM virt machine which is a relatively > small DT. My test case went from 118072 bytes ddown to 21548 bytes with this series. Tested-by: Nicolas Pitre Nicolas