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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 360D6C433F5 for ; Fri, 27 May 2022 16:30:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AE5038D0007; Fri, 27 May 2022 12:30:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A97CB8D0001; Fri, 27 May 2022 12:30:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 981048D0007; Fri, 27 May 2022 12:30:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 8BDF28D0001 for ; Fri, 27 May 2022 12:30:22 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 569A960996 for ; Fri, 27 May 2022 16:30:22 +0000 (UTC) X-FDA: 79512060684.14.1AAC35F Received: from mail-ua1-f54.google.com (mail-ua1-f54.google.com [209.85.222.54]) by imf28.hostedemail.com (Postfix) with ESMTP id 77125C004E for ; Fri, 27 May 2022 16:29:47 +0000 (UTC) Received: by mail-ua1-f54.google.com with SMTP id y2so1752182uan.4 for ; Fri, 27 May 2022 09:30:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9g6mz1ylmv173XWWIuI9CzS3Wpc02dZXxX1VqooLv6M=; b=ICPj8M19sLww6myKVnMx7K4vHlePmm+tmuVa2CCBroqezT99t1DinF9BZu3oSQWi95 PpHxUge67hCiEN+WbmdFcFmp8LoaNqXmtffkzJy1t2bg6QFSpt+0cta9Vh/exFeakeY8 ES6R1K20FZEi8DvnQo+3jrpIm5FGofSrhASDaagpHZYCBydJb1rbBRkKTUKmMN2hpZbm FRCTGunZ2yKbLACuUH57tkyr0bh7HuM09UnLIwgdDTL+WogL5Yjb2zxog50f0Rjsgd8z Cctn/w1tgtMEDvEQuXCz2/zfx4aQ/YRaYg3+SGh/W7Ihl0m86+RY8kWo0ZD2STUDzwff u6xw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9g6mz1ylmv173XWWIuI9CzS3Wpc02dZXxX1VqooLv6M=; b=JrHp+p2c0dVsNY9fr4WO92JFmKBA7AT/l6ZNKJ99ejTfmZ6OImm8tTOIMp2FbsYfxU pQV6BjTfDQF9maZGwPN2XGIhqOslxaj7WNYNJLpjrurnjI1MsN/q+t7L1B0gC0I934fh cuVbHqfDWTbg0+I5lIHO12V9WNj5+wEGtT4lkxdqtw+tFDe6wZplkDJHeHZcgnuFeD3G oBKbQ+HNwhKx5tvdhewgTYIP9rT2Lt9UjCzkRAWSbDY0ugE1TXIi7Qm4+/jACXEE9WLj Q2k3qKRlnnOHmzIijl1gd3fZrvkcrXm3avOIlTnD6nn3/7O7PLQL2zQ4cOmswEgo7bXm 53XA== X-Gm-Message-State: AOAM5302ubnrJgIAxtAKV9fnWbk06H10DsnObxcCEkYPIkwnhuXNokSO 8ImMG10g6DP43hLzUK5qiT0sh3UVJifMrCG8XaGtmw== X-Google-Smtp-Source: ABdhPJzt+PohqIGTGjBpgaRI7q35Gs5Fzbmr+cx7m/7GoZaI2EB6hlNIf7D72yOYQIlLGACN2Xz+OWyWgoTOKR9NHJQ= X-Received: by 2002:a9f:3592:0:b0:365:ef07:68c9 with SMTP id t18-20020a9f3592000000b00365ef0768c9mr15993279uad.60.1653669021023; Fri, 27 May 2022 09:30:21 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Wei Xu Date: Fri, 27 May 2022 09:30:10 -0700 Message-ID: Subject: Re: RFC: Memory Tiering Kernel Interfaces (v3) To: Aneesh Kumar K V Cc: Huang Ying , Andrew Morton , Greg Thelen , Yang Shi , Davidlohr Bueso , Tim C Chen , Brice Goglin , Michal Hocko , Linux Kernel Mailing List , Hesham Almatary , Dave Hansen , Jonathan Cameron , Alistair Popple , Dan Williams , Feng Tang , Linux MM , Jagdish Gediya , Baolin Wang , David Rientjes Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 77125C004E X-Stat-Signature: czscmoeptogwp6thixcjhrf6nc1y16tg Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=ICPj8M19; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf28.hostedemail.com: domain of weixugc@google.com designates 209.85.222.54 as permitted sender) smtp.mailfrom=weixugc@google.com X-Rspam-User: X-Rspamd-Server: rspam11 X-HE-Tag: 1653668987-690468 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, May 27, 2022 at 6:41 AM Aneesh Kumar K V wrote: > > On 5/27/22 2:52 AM, Wei Xu wrote: > > > The order of memory tiers is determined by their rank values, not by > > their memtier device names. > > > > - /sys/devices/system/memtier/possible > > > > Format: ordered list of "memtier(rank)" > > Example: 0(64), 1(128), 2(192) > > > > Read-only. When read, list all available memory tiers and their > > associated ranks, ordered by the rank values (from the highest > > tier to the lowest tier). > > > > Did we discuss the need for this? I haven't done this in the patch > series I sent across. The "possible" file is only needed if we decide to hide the directories of memtiers that have no nodes. We can remove this interface and always show all memtier directories to keep things simpler. > We do have > /sys/devices/system/memtier/default_rank which should allow user to > identify the default rank to which memory would get added via hotplug if > the NUMA node is not part of any memory tier. Sounds good to me to have it. > > -aneesh