From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 7D892828E1 for ; Fri, 5 Aug 2016 11:36:46 -0400 (EDT) Received: by mail-it0-f70.google.com with SMTP id i64so70230339ith.2 for ; Fri, 05 Aug 2016 08:36:46 -0700 (PDT) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id l5si16846918ioe.59.2016.08.05.01.19.04 for ; Fri, 05 Aug 2016 01:19:05 -0700 (PDT) Date: Fri, 5 Aug 2016 17:20:15 +0900 From: Minchan Kim Subject: Re: [linux-mm] Drastic increase in application memory usage with Kernel version upgrade Message-ID: <20160805082015.GA28235@bbox> References: <01a001d1eed5$c50726c0$4f157440$@samsung.com> MIME-Version: 1.0 In-Reply-To: <01a001d1eed5$c50726c0$4f157440$@samsung.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: PINTU KUMAR Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, jaejoon.seo@samsung.com, jy0.jeon@samsung.com, vishnu.ps@samsung.com On Fri, Aug 05, 2016 at 10:26:37AM +0530, PINTU KUMAR wrote: > Hi All, > > For one of our ARM embedded product, we recently updated the Kernel version from > 3.4 to 3.18 and we noticed that the same application memory usage (PSS value) > gone up by ~10% and for some cases it even crossed ~50%. > There is no change in platform part. All platform component was built with ARM > 32-bit toolchain. > However, the Kernel is changed from 32-bit to 64-bit. > > Is upgrading Kernel version and moving from 32-bit to 64-bit is such a risk ? > After the upgrade, what can we do further to reduce the application memory usage > ? > Is there any other factor that will help us to improve without major > modifications in platform ? > > As a proof, we did a small experiment on our Ubuntu-32 bit machine. > We upgraded Ubuntu Kernel version from 3.13 to 4.01 and we observed the > following: > -------------------------------------------------------------------------------- > ------------- > |UBUNTU-32 bit |Kernel 3.13 |Kernel 4.03 |DIFF | > |CALCULATOR PSS |6057 KB |6466 KB |409 KB | > -------------------------------------------------------------------------------- > ------------- > So, just by upgrading the Kernel version: PSS value for calculator is increased > by 409KB. > > If anybody knows any in-sight about it please point out more details about the > root cause. One of culprit is [8c6e50b0290c, mm: introduce vm_ops->map_pages()]. -- 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