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 4E481EE4993 for ; Tue, 22 Aug 2023 09:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234139AbjHVJBY (ORCPT ); Tue, 22 Aug 2023 05:01:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234032AbjHVJBV (ORCPT ); Tue, 22 Aug 2023 05:01:21 -0400 Received: from mail-qt1-x82e.google.com (mail-qt1-x82e.google.com [IPv6:2607:f8b0:4864:20::82e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48991CE for ; Tue, 22 Aug 2023 02:01:20 -0700 (PDT) Received: by mail-qt1-x82e.google.com with SMTP id d75a77b69052e-40a47e8e38dso174451cf.1 for ; Tue, 22 Aug 2023 02:01:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692694879; x=1693299679; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=MPEBgG45Y8MpD7W1zMd0c6pmHvwhLPDAtwYLm/BJKLA=; b=3wrNqYQ+7EAzvkwTwoOwP0NDvTHC/mtkHpGRvM1waGeTAxTcMsI597HtzHK3NVJeKe v3g6sa1Lekcr690elqNpaNVbJwkjTKKDWKJPAuSxOiWuZrWsXQQmPzabU8fkqV6w5zju 8KkZlp4uafNA4Q5e539gxHjvf9azY/2deX5Wm59wrKKJKg1hLOmAUwfSPeiBZ7PIdqoy e+Vn47AaD5UNcfN4c3BGbHD3Wode0pTjL509WZW/PIZuYF5WPnAcQxnYAiamIFKbS1vo XdyCR5GJZ/WUJXTay48jTg/yIxvkd8ObucBmq7c7rqSfL5Fmxo2o8WONU/25IojlaV3W cJDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692694879; x=1693299679; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=MPEBgG45Y8MpD7W1zMd0c6pmHvwhLPDAtwYLm/BJKLA=; b=MGxudZ6FQIDY8dFbAAn5W7m5Hw0Ql/2su6qBHMJZzwpQapE/h+ljkdbHaurHskitG6 qB6fQXmxXYHJQr4I33nXPybjhIIb2BRBozvym7DJsai27gwxr1rHdpg2Q7cfFdE1c47l QNLNQcvZG3zn9JPno2Gg08KGL5lJPNNH9D1eQqke5thodQc3PzwLU2YsijOAvI1xanQC akF9BBn1wsYUuuvoUwz/cga0l9q0NmkKJ3aQw9YN3RhDYBnVl3bBNnr5mRaMWDr8cTjX DdPNujo7/KtezPBrSvZhc6UgZPMMxGZ5MD1t9iu7DSDpACULFBy5d3cBBjhJaZbYSlsX +lEQ== X-Gm-Message-State: AOJu0Yw/GgxLpMaxqJXukKqKJv5H2vwM79WWK0CxZvsYI+tsL54ddj/P uEO9C6klHhdsc0zCe1Z3WKXqb0/wMlmvrowLgcPlhrOJqidkGXgDaEw= X-Google-Smtp-Source: AGHT+IER7LvBvaYnM4J9NLx4oCGgsKlywejZtCh0hhgSSGgDbc6Ffd4NpqGPxGCFSJQihm++T/7jWu9jFFNA2O3Zfuw= X-Received: by 2002:ac8:5a47:0:b0:410:653f:90e8 with SMTP id o7-20020ac85a47000000b00410653f90e8mr148542qta.11.1692694879266; Tue, 22 Aug 2023 02:01:19 -0700 (PDT) MIME-Version: 1.0 References: <20230815152712.1760046-1-amitsinght@marvell.com> In-Reply-To: <20230815152712.1760046-1-amitsinght@marvell.com> From: Peter Newman Date: Tue, 22 Aug 2023 11:01:08 +0200 Message-ID: Subject: Re: [RFC 00/12] ARM: MPAM: add support for priority partitioning control To: Amit Singh Tomar Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, fenghua.yu@intel.com, reinette.chatre@intel.com, james.morse@arm.com, gcherian@marvell.com, robh@kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Amit, On Tue, Aug 15, 2023 at 5:27=E2=80=AFPM Amit Singh Tomar wrote: > As an example, "schemata" file under resource control group contains info= rmation about > cache portion bitmaps, and memory bandwidth allocation, and these are use= d to configure > Cache portion partition (CPOR), and MPAM bandwidth partitioning controls. > > MB:0=3D0100 > L3:0=3Dffff > > But resctrl doesn't provide a way to set-up other control that ARM MPAM p= rovides > (For instance, Priority partitioning control as mentioned above). To supp= ort this, > James has suggested to use already existing schemata to be compatible wit= h > portable software, and this is the main idea behind this RFC is to have s= ome kind > of discussion on how resctrl can be extended to support priority partitio= ning control. > > To support Priority partitioning control, "schemata" file is updated to a= ccommodate > priority field (upon priority partitioning capability detection), separat= ed from CPBM > using delimiter ",". > > L3:0=3Dffff,f where f indicates downstream priority max value. Do we really have to mash two controls into the same schema? In the CDP example, the code/data controls are presented as multiple schema, for example: "L3CODE, L3DATA" Especially when reading back the schemata file, it seems like it would be simpler for existing software to ignore unfamiliar schema lines in the schemata file than to overlook the introduction of a comma to the CBM in the existing "L3" schema. Thanks! -Peter