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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0618CE95A86 for ; Sun, 8 Oct 2023 01:17:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344226AbjJHBRL (ORCPT ); Sat, 7 Oct 2023 21:17:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229634AbjJHBRJ (ORCPT ); Sat, 7 Oct 2023 21:17:09 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AEF158F; Sat, 7 Oct 2023 18:17:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1696727828; x=1728263828; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=BObmF+e1EHfAcOcXWcw1IxrBQsQNIWGH7aR97cf+Zh4=; b=Gyhe3xeAlVflBgX3cmPyUHIdQByb/faclzNH8gvbsIfZERAxGIlcwTJq s14mJMl8/zYYjRLBYgBJ4YZ5EszMKUUDxwHCK4zx1ZXEOX7Sy4semLZNz L8ps+rS4M21bhWR6z4AfTgJxzuRr9kJf0b1Lxb8e/usoTng8Ssj21xbYy 0ApCLZr2S88LPb/YQDwIkmeFdiK1RvMasYbKebITrEVMvK0Synsi1mAEP uueBJGcJ6xlASRZWUBZjIz9tACu/dbGQTAWE9S16OTJAiXabM23agHEvX o5Z7so/W4J2e/hrR7odac+3uRHablCc9StKnMivFhdfQSp525zdIbwN57 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10856"; a="387834737" X-IronPort-AV: E=Sophos;i="6.03,207,1694761200"; d="scan'208";a="387834737" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Oct 2023 18:17:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10856"; a="729268794" X-IronPort-AV: E=Sophos;i="6.03,207,1694761200"; d="scan'208";a="729268794" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Oct 2023 18:17:01 -0700 From: "Huang, Ying" To: Jianlin Lv Cc: tj@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org, corbet@lwn.net, mhocko@kernel.org, roman.gushchin@linux.dev, shakeelb@google.com, muchun.song@linux.dev, akpm@linux-foundation.org, yosryahmed@google.com, willy@infradead.org, linmiaohe@huawei.com, wangkefeng.wang@huawei.com, laoar.shao@gmail.com, yuzhao@google.com, wuyun.abel@bytedance.com, david@redhat.com, peterx@redhat.com, vishal.moola@gmail.com, hughd@google.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, jianlv@ebay.com Subject: Re: [PATCH] memcg: add interface to force disable swap References: <20231007130905.78554-1-jianlv@ebay.com> Date: Sun, 08 Oct 2023 09:14:54 +0800 In-Reply-To: <20231007130905.78554-1-jianlv@ebay.com> (Jianlin Lv's message of "Sat, 7 Oct 2023 21:09:05 +0800") Message-ID: <87mswtkj8x.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jianlin Lv writes: > From: Jianlin Lv > > Global reclaim will swap even if swappiness is set to 0. Why? Can you elaborate the situation? > In particular > case, users wish to be able to completely disable swap for specific > processes. One scenario is that if JVM memory pages falls into swap, > the performance will noticeably reduce and the GC pauses tend to increase > to levels not tolerable by most applications. > If it's possible to only disable swap out for specific processes, it can > address the JVM GC pauses issues, and at the same time, memory reclaim > pressure is also manageable. > > This patch adds "memory.swap_force_disable" control file to support disable > swap for non-root cgroup. When process is associated with a cgroup, > 'echo 1 > memory.swap_force_disable' will forbid anon pages be swapped out. > This patch also adds read and write handler of the control file. -- Best Regards, Huang, Ying