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 A30A9C28D13 for ; Sat, 20 Aug 2022 00:40:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2FB218D0003; Fri, 19 Aug 2022 20:40:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2AB088D0002; Fri, 19 Aug 2022 20:40:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 14B9A8D0003; Fri, 19 Aug 2022 20:40:12 -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 F237D8D0002 for ; Fri, 19 Aug 2022 20:40:11 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C2A45C0383 for ; Sat, 20 Aug 2022 00:40:11 +0000 (UTC) X-FDA: 79818114222.18.516161A Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf21.hostedemail.com (Postfix) with ESMTP id 3543B1C005A for ; Sat, 20 Aug 2022 00:34:36 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 42A66B8299F; Sat, 20 Aug 2022 00:34:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6504FC433C1; Sat, 20 Aug 2022 00:34:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1660955673; bh=exwuMdrg5qTnP1tlzlM00aIWZ/dJVmjgxKylsvSYu3k=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=aVTNR7yq91xjdaURJaNSqLHunfakxxuUr/eEVrt8kMCHd+Q91enZvb4cMVE7g2IkI TzS35VhknhyIpH4y2y6h6y9EjMTZvcuJZVeJ1CbuaKN2WxNjrkPtXUkVzFxFc4h79h 4r2b/jCQM2N0jf4U8fRU41O1bsyqEjM2wxMSaHiw= Date: Fri, 19 Aug 2022 17:34:31 -0700 From: Andrew Morton To: Bharata B Rao Cc: "Aneesh Kumar K.V" , linux-mm@kvack.org, Wei Xu , Huang Ying , Yang Shi , Davidlohr Bueso , Tim C Chen , Michal Hocko , Linux Kernel Mailing List , Hesham Almatary , Dave Hansen , Jonathan Cameron , Alistair Popple , Dan Williams , Johannes Weiner , jvgediya.oss@gmail.com Subject: Re: [PATCH v15 00/10] mm/demotion: Memory tiers and demotion Message-Id: <20220819173431.5c391297042eff209e821088@linux-foundation.org> In-Reply-To: <137cf90f-abf9-4a6d-08fb-ef3922685ba5@amd.com> References: <20220818131042.113280-1-aneesh.kumar@linux.ibm.com> <137cf90f-abf9-4a6d-08fb-ef3922685ba5@amd.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660955676; a=rsa-sha256; cv=none; b=fJiTqVwW/cx2LtR/S5Id/dC7GCfRQEk2Y571KvlNfd6kiPPfmMhZJYXfRXvbTKKaF3u2j4 qnEwQNvKU3DZzfQWHijkCZ3rtdbQsn8DLm9QzvHxwbuEcVrbiyXIk8xPJr/Gl5rIdufFXQ i5vc2J1ZVLo8Vr7ruqyGT/xMxnn+0oM= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=aVTNR7yq; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660955676; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=jG+hYaMTFuEnCQzW6i/U9PjjwSDfbZR6WqryZBdhgvI=; b=Ss6oayvtC+qSoIxXmJ2WKNceMAhYa/Jtkak8eM7/JT5AZh9w0g9nNg4ppxbDQAcLP0AT8H ndSW47K5EHMeURPoHrua/TZIe1hzgpbWkR8n3jMZmQD0q3GHPqChj4F+IkWSzD+a9FBSnk bJHdsRyS2EqOv+2IJT/u//tYnlmYdSk= X-Rspamd-Server: rspam06 X-Rspam-User: X-Stat-Signature: nfn5xbtkeywf6pgr1t8fzy9us1s53kf4 Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=aVTNR7yq; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Queue-Id: 3543B1C005A X-HE-Tag: 1660955676-576063 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, 19 Aug 2022 11:57:18 +0530 Bharata B Rao wrote: > > The kernel initialization code makes the decision on which exact tier a memory > > node should be assigned to based on the requests from the device drivers as well > > as the memory device hardware information provided by the firmware. > > I gave this patchset a quick try on two setups: > > 1. With QEMU, when an nvdimm device is bound to dax kmem driver, I can see > the memory node with pmem getting into a lower tier than DRAM. > > 2. In an experimental CXL setup that has DRAM as part of CXL memory, I see that > CXL memory node falls into the same tier as the regular DRAM tier. This is > expected for now since there is no code (in low level ACPI driver?) yet to > map the latency or bandwidth info (when available from firmware) into an > abstract distance value, and register a memory type for the same. Guess these > bits can be covered as part of future enhancements. Should I add your Tested-by:?