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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 7EB8BC43381 for ; Fri, 15 Mar 2019 10:08:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42DDE2186A for ; Fri, 15 Mar 2019 10:08:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ashwireless-com.20150623.gappssmtp.com header.i=@ashwireless-com.20150623.gappssmtp.com header.b="qlh5YoIA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728810AbfCOKH7 (ORCPT ); Fri, 15 Mar 2019 06:07:59 -0400 Received: from mail-wm1-f47.google.com ([209.85.128.47]:55557 "EHLO mail-wm1-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727428AbfCOKH6 (ORCPT ); Fri, 15 Mar 2019 06:07:58 -0400 Received: by mail-wm1-f47.google.com with SMTP id 4so5843617wmf.5 for ; Fri, 15 Mar 2019 03:07:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ashwireless-com.20150623.gappssmtp.com; s=20150623; h=to:from:subject:message-id:date:user-agent:mime-version :content-transfer-encoding:content-language; bh=BlL/ECopNu618o3zband1lVVMnlB11F+5+kb5RBUYRk=; b=qlh5YoIApKYil6Rq2+s+R9NO30FNtA5bMiAVd2029XsW/kIqRTgK8O2Ec/bh+Ylzwf 5vpUAL5WpQ2MAaq5HXoMBjHUYp2ba9nt9Rsu1f+KE2NfQw5RGzFETQBgimNbo6FYt1qE 8lZqCekzpcoBxJC3S3u6nhnzXDJronlamK97Jt4iENZZRqBUzA+gTqwW5Gp6B0H2VMCZ RQlMT3xF9W5gbF+ZnjN/OJ+mC3iSd2ji0vFuZL2aZdDHu74tWdltT/ITFQBYmosq5HJw p1+kxMCdxcIpS0884lc59adgIq/mWVZxB2wrTuamDEfvPl3YgWdcPwIPj5AOlRhNHQiE /59Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-transfer-encoding:content-language; bh=BlL/ECopNu618o3zband1lVVMnlB11F+5+kb5RBUYRk=; b=hPaHaOeqZ9zVcmHXTT/NOjtxhvxbQuYXWtYXE3eaJNnMHvg5YoJ6koV75a5Dlf7pCr SMtxfJ/BVjP6Aro0YkR4NdXxjGLI8U9BIoaJj/2LmgmXhyJSvk+MAIPGbrt6OxpbNIJk M0E7bg+HCfSM7GteSDCa27RumQb53V491TfjWkyJSYmsqBKzvjcl1F6+6qubQScUh/uo gUbGjBslpBsNwzQnCZz46VI2wCejJtAIdep+ZzO2KGYAsy0qgAZlYTbuWue7L630Q5wl 32DBe+q5XQrdkTtfWPBeHcLoGQdfDBI6PYHfoyoVXbsQGT0GBGfUV6FwoqlgMCD0Vk53 XdOw== X-Gm-Message-State: APjAAAXmwzw4NMnRshn0gmuQFfonqa9TI+1nieKY63wO5GdbeMnpSWz+ 6mWnQr/ysA8T4SoFcHZAM0g9dT3qT4Q= X-Google-Smtp-Source: APXvYqyPG2qA4aaKZ+FJWFV4AZZoLwzZ+Cf7Jq7xPdH2jDaLnI+9lPnayGB314loDzg/ICXS7dlwrg== X-Received: by 2002:a7b:c344:: with SMTP id l4mr1481474wmj.121.1552644476617; Fri, 15 Mar 2019 03:07:56 -0700 (PDT) Received: from [192.168.0.117] ([88.215.34.26]) by smtp.gmail.com with ESMTPSA id y12sm1736376wma.44.2019.03.15.03.07.55 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Mar 2019 03:07:56 -0700 (PDT) To: linux-kernel@vger.kernel.org From: Michael Haben Subject: Memory-compaction not working on Atmel SAMA5 ARM platform, kernel v4.14 and v4.20 Message-ID: Date: Fri, 15 Mar 2019 10:07:53 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello all, Memory-compaction is not working for me on an Atmel SAMA5D2 SoC with 128Mbyte of RAM, on kernel versions 4.14.73. 4.14.88 and 4.20.0 Using "cat /proc/buddyinfo" to observe the state of memory fragmentation, and "echo 1 > /proc/sys/vm/compact_memory" to (try to) trigger compaction. My kernel's /proc/config.gz includes "CONFIG_COMPACTION=y" and "CONFIG_MIGRATION=y" I have rebuilt v4.20 several++ times, enabling various "CONFIG_xxx" items trying to enable tracing, but without success (/sys/kernel/debug/tracing is not present), so I haven't been able to observe whether the compaction-trigger is having any effect at all. Some circumstantial evidence: memory-compaction was working on another ARM platform (Raspberry Pi) with kernel v4.9 (Raspbian Jessie), but stopped working when I dist-upgraded it to v4.14.98 (Raspbian Stretch).  The " /proc/sys/vm/compact_memory" device-node is present, but writing to it has no effect on the output from "cat /proc/buddyinfo". So my questions are: 1.  Are "CONFIG_COMPACTION=y" + "CONFIG_MIGRATION=y" the only settings necessary for memory-compaction to be present and working in a kernel?  I have Done My Own Research, but Am Not An Expert on Linux kernel features! 2.  Must I persevere with trying to get tracing working, or is there another way I can debug this issue? Thank you, Mike Haben ASH Wireless