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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 E0603C63697 for ; Mon, 16 Nov 2020 17:54:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AD56222E8 for ; Mon, 16 Nov 2020 17:54:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388115AbgKPRyJ (ORCPT ); Mon, 16 Nov 2020 12:54:09 -0500 Received: from mga17.intel.com ([192.55.52.151]:64547 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731494AbgKPRyJ (ORCPT ); Mon, 16 Nov 2020 12:54:09 -0500 IronPort-SDR: 0S3Tzo7mf440JBxqqc4HGtVysulprgsREZ5CR6PUzacXbF1nuTG4ocDSkU6ywyXth6s6gj+XRB MinB4CxFY++w== X-IronPort-AV: E=McAfee;i="6000,8403,9807"; a="150635270" X-IronPort-AV: E=Sophos;i="5.77,483,1596524400"; d="scan'208";a="150635270" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Nov 2020 09:54:08 -0800 IronPort-SDR: Jdlixqe5R54E9j8V1xGVAl0Bcy031EU+NE8I464ZLtdsj6R+Ow+Y4nFi6QYqoSRagDCjbi6Zm5 TSpQMuix5vMg== X-IronPort-AV: E=Sophos;i="5.77,483,1596524400"; d="scan'208";a="358548867" Received: from rchatre-mobl3.amr.corp.intel.com (HELO [10.209.146.140]) ([10.209.146.140]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Nov 2020 09:54:07 -0800 Subject: Re: [PATCH 00/24] x86/resctrl: Merge the CDP resources To: James Morse , x86@kernel.org, linux-kernel@vger.kernel.org Cc: Fenghua Yu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , shameerali.kolothum.thodi@huawei.com, Jamie Iles , D Scott Phillips OS References: <20201030161120.227225-1-james.morse@arm.com> From: Reinette Chatre Message-ID: <04fdd774-99e0-4b99-2d70-06cfd0ab3be6@intel.com> Date: Mon, 16 Nov 2020 09:54:06 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.3 MIME-Version: 1.0 In-Reply-To: <20201030161120.227225-1-james.morse@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi James, On 10/30/2020 9:10 AM, James Morse wrote: > MPAM has an equivalent feature to CDP, but its a property of the CPU, > not the cache. Resctrl needs to have x86's odd/even behaviour, as that > its the ABI, but this isn't how the MPAM hardware works. It is entirely > possible that an in-kernel user of MPAM would not be using CDP, whereas > resctrl is. The above seems to distinguish between "in-kernel user of MPAM" and resctrl (now obtaining support for MPAM). Could you please provide more details on the "in-kernel user of MPAM" and elaborate on how these two usages are expected to interact with MPAM concurrently? Thank you Reinette