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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 BAE3FC433B4 for ; Mon, 12 Apr 2021 14:03:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A93C611AD for ; Mon, 12 Apr 2021 14:03:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242077AbhDLOED (ORCPT ); Mon, 12 Apr 2021 10:04:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238998AbhDLOEA (ORCPT ); Mon, 12 Apr 2021 10:04:00 -0400 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DEC5C06174A for ; Mon, 12 Apr 2021 07:03:41 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id v140so21604642lfa.4 for ; Mon, 12 Apr 2021 07:03:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Txa0jtEnzVHszI7+7RurZSdLkTftdeKdRRITuMLu8Aw=; b=PKU//OewynQNd7SeSC4KENGCXLIca0cApDWlmgkcNZDG1kpsbr0rPgil0AfgvOY6dl xyI6oUsEgz7I5NjvX0nmU5gKYvslpr/DlU2IIRtDHNsKTNj5mYTMWpVOpf0jlmmt/S1y CUUPJrpfVC9XLPr2/2KydVFWwL1JDLBVppMWOyO+Az5d4syy4eLTXKVvpJh2no8LrH7e ex2ev3hbHYWC5eF6K2hYH3cFW/+lq19/RnT0xtAF8Di+nXWZY6q/eFfZ0rQhHO906gw/ 8g5iI2BKxf1UF0j4bm0jF5b9TGq687Vz2mq2c0Pjjaq4ByhtTs/YAEQgxKfs2aA9Fml4 jqyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Txa0jtEnzVHszI7+7RurZSdLkTftdeKdRRITuMLu8Aw=; b=paGrxJBNmVFOFsvF8RCN4o5LojcHTjJdCNsWaW+fcrTNE0ZGRs2nMn+N4j71Co0wc2 rUAl7E3a+bPdkJofD3zpEmIn888veKN/Kap7k8MfH5HSIka8oABr9A3j4k/cF+YL4pfv DTCpEzhdNvGs4fAi/fpSBwTyx6he6kcjEzUcQXzkecC4tdUdeQXGQUeWJSb/CEWv29uz DDm67tdK6vj+Vq+Lhd9eNLN5ipC9cJzdL4Yyb0S5E+z016lR6wG6p3jPbVK6HWpgAJsB 5DSX088LGpb07UeTTGoBFYKB3yZ4/4TtERMgzle3vIlLRaCO/kYflRqHgiLhE3ErV3mq uQIg== X-Gm-Message-State: AOAM533pzxyQHDmnZww73Rx6nwukwgtCsPt0PyKDTsscK2PydMy/DOVf V9HaSZKeu0Ey3B+dyI3+vpklaE5rC478iT7/Z1EKlg== X-Google-Smtp-Source: ABdhPJwdMgH1vZSbLM2ftjQCiG02Bjb8iz3/wBlG8KsX8dUvbr+SMIdSWmWYv9eRFDg9nnny7qYgsT+gUxtHK7Iklhc= X-Received: by 2002:ac2:546c:: with SMTP id e12mr4490386lfn.299.1618236219038; Mon, 12 Apr 2021 07:03:39 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Shakeel Butt Date: Mon, 12 Apr 2021 07:03:27 -0700 Message-ID: Subject: Re: [RFC PATCH v1 00/11] Manage the top tier memory in a tiered memory To: Yang Shi Cc: Tim Chen , Michal Hocko , Johannes Weiner , Andrew Morton , Dave Hansen , Ying Huang , Dan Williams , David Rientjes , Linux MM , Cgroups , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 8, 2021 at 1:50 PM Yang Shi wrote: > [...] > > > > The low and min limits have semantics similar to the v1's soft limit > > for this situation i.e. letting the low priority job occupy top tier > > memory and depending on reclaim to take back the excess top tier > > memory use of such jobs. > > I don't get why low priority jobs can *not* use top tier memory? I am saying low priority jobs can use top tier memory. The only difference is to limit them upfront (using limits) or reclaim from them later (using min/low/soft-limit). > I can > think of it may incur latency overhead for high priority jobs. If it > is not allowed, it could be restricted by cpuset without introducing > in any new interfaces. > > I'm supposed the memory utilization could be maximized by allowing all > jobs allocate memory from all applicable nodes, then let reclaimer (or > something new if needed) Most probably something new as we do want to consider unevictable memory as well. > do the job to migrate the memory to proper > nodes by time. We could achieve some kind of balance between memory > utilization and resource isolation. > Tradeoff between utilization and isolation should be decided by the user/admin.