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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 3E092C433DF for ; Fri, 3 Jul 2020 04:59:15 +0000 (UTC) Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ED7CE208FE for ; Fri, 3 Jul 2020 04:59:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED7CE208FE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=vt.edu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernelnewbies-bounces@kernelnewbies.org Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.94) (envelope-from ) id 1jrDmj-0007bV-3z; Fri, 03 Jul 2020 00:58:49 -0400 Received: from omr2.cc.ipv6.vt.edu ([2607:b400:92:8400:0:33:fb76:806e] helo=omr2.cc.vt.edu) by shelob.surriel.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1jrDmg-0007bM-SK for Kernelnewbies@kernelnewbies.org; Fri, 03 Jul 2020 00:58:46 -0400 Received: from mr2.cc.vt.edu (junk.cc.ipv6.vt.edu [IPv6:2607:b400:92:9:0:9d:8fcb:4116]) by omr2.cc.vt.edu (8.14.4/8.14.4) with ESMTP id 0634wjms028242 for ; Fri, 3 Jul 2020 00:58:45 -0400 Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) by mr2.cc.vt.edu (8.14.7/8.14.7) with ESMTP id 0634weSB020187 for ; Fri, 3 Jul 2020 00:58:45 -0400 Received: by mail-qk1-f200.google.com with SMTP id i3so14736047qkf.0 for ; Thu, 02 Jul 2020 21:58:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:in-reply-to:references :mime-version:content-transfer-encoding:date:message-id; bh=6N1kW69i2pxJ+IDeFBBawgLTAWMJ8xjM0QMcIYFpn04=; b=B/XQ5XddQccsV+6Mdc1pAzRPjXENnJCM+tTaHlsyP86qQmrC4cfHBRmphZ60ZEh7k6 OD1trL8selHozplpnYjsi0xuJQebeyPdyW8Cd+NP+jlyqtmFdcmWvodQRf+LZM4lQ9Ck 1XncLtvLdachMZnVRbx2wFqno+k55Jg4BhuoebRGk+G5xLWESDTQCy2bIixGbYojNfd0 U/D7MUk3Ck4AnZ/gvPnflw/rOljOJtsgbW+9jq2qvvNiguHOgn3Hf+YUF7OAIHlbOJ7d 29ZL8yji0pzMq0U+ae65PK4fx0QOPmk5ZEm1KJArESzWaGzEZkq3S5wbYsTNCTdesLRa trHg== X-Gm-Message-State: AOAM531GMLnIHBgs6q5moXB9/TJ8AgKhzqGVunn1QcBUjH/wycD3I8OS zXK+o92NNA68JRZvtzzdE/A01+gvCpKUk1F/SmuHLxcAr/pljMFpdN2BwsxrQrGFukl3kFzE756 pJcD9qiHgYDycf/R3V/uEqmhllFKyChaaTpY7AJM= X-Received: by 2002:a0c:e048:: with SMTP id y8mr33747506qvk.11.1593752319970; Thu, 02 Jul 2020 21:58:39 -0700 (PDT) X-Google-Smtp-Source: ABdhPJw83yoLjxVMVUeosih3UN/dlN242ow5w75I86k+9n+GyF27hJXot5aFYpOhzd7cbWDanujQPQ== X-Received: by 2002:a0c:e048:: with SMTP id y8mr33747498qvk.11.1593752319617; Thu, 02 Jul 2020 21:58:39 -0700 (PDT) Received: from turing-police ([2601:5c0:c001:c9e1::359]) by smtp.gmail.com with ESMTPSA id y23sm10324486qkj.25.2020.07.02.21.58.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 21:58:38 -0700 (PDT) From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" X-Google-Original-From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7+dev To: Mulyadi Santosa Subject: Re: Is there some method or software that could purposely generate a lot of physical memory fragmentations on linux? In-Reply-To: References: Mime-Version: 1.0 Date: Fri, 03 Jul 2020 00:58:37 -0400 Message-ID: <6499.1593752317@turing-police> Cc: kernelnewbies X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============7933861836903718969==" Errors-To: kernelnewbies-bounces@kernelnewbies.org --===============7933861836903718969== Content-Type: multipart/signed; boundary="==_Exmh_1593752317_6303P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit --==_Exmh_1593752317_6303P Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Thu, 02 Jul 2020 15:29:18 +0700, Mulyadi Santosa said: > Just pseudo idea, if this is in user space, try to: allocate many bloc= ks > of memory using malloc, each having different size, keep the returned > pointer, then randomly free() some of them, then malloc() again with > different size That will cause userspace malloc() to have fragmentation, but as far as the kernel is concerned it's all just 4K pages of user memory. Causing physical memory fragmentation will require abusing the kernel memory allocators such as kmalloc() and vmalloc() and friends. --==_Exmh_1593752317_6303P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Comment: Exmh version 2.9.0 11/07/2018 iQIVAwUBXv66/AdmEQWDXROgAQKSKQ/9HQN2i18jNjonZgnet4Cpzef8RU5HVl3c cqX+xqY4qjwsKDw5iFT2cQRDR35cZgYX/cQGdB0mnFNEsZ5VGmEH6Kl12fAwYLib uAWuNV5FzQxRQuMH7hlwzMdhWAlAGZqNARNaLx3jNkEDwKiYII447yfi6ISt5xea XYDiVofNQ9LlXYU6JsxLQN8tzyCVzhNT1bHOcwLqoJfRJntgglXhi5hpZAIl0lVP 21MZ6eQI1epl9jiQA0sE+oIXPLR3R/zVLfIsxK1noZI3ii663C2EUwr8G0NhjLBI YYXX/XlX+Gb89bcnSr6soAZwd0GG294fm5VU9jeokcHQDve4LuebohQ0Cf5yEI3w pJS3Tdr33mrfxsmtjDCZDIxVvI5UEAsQ1AI+saJGTr0kU+1VzqMGRnR+GSwXYwFy 9MNehXU+Q5gxJjn/BGSQL/SBfIgVNTxlNCfq0UA5/AGCFw6MPYDD+q2QHkFBt3ER iLDgJ++57VySqo/2PHFJXtqHZd+cMnSPRFlNQbX4Gw2TitpEyldRG6l3aMbh3Wtl E2HZLQUgoYDRyd7iJTuMcaun5onLB3rRZ4lHgK6v6i1X2sTkV0vvnskzDUfF0AcT YF3DGb+B7uoUfou7mcaXBETwbd2py8aCzBo5GeIGOVV6j3OlaiHvK5lg79x3OuFy kH5T2drv0fs= =PKjD -----END PGP SIGNATURE----- --==_Exmh_1593752317_6303P-- --===============7933861836903718969== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies --===============7933861836903718969==--