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 02861C28D13 for ; Sat, 20 Aug 2022 00:34:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245270AbiHTAel (ORCPT ); Fri, 19 Aug 2022 20:34:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245250AbiHTAef (ORCPT ); Fri, 19 Aug 2022 20:34:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01AEDBC14 for ; Fri, 19 Aug 2022 17:34:34 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 9513B61909 for ; Sat, 20 Aug 2022 00:34:33 +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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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:?