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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 83970D2F338 for ; Tue, 13 Jan 2026 15:39:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=J71ebHvzIZket0gMmVsHAgoFIWh+Qd9qgxdehVtOTqc=; b=Bz+bbL1n1ZfqboesNs0zHKllb+ nFF9LbXzoh4KBKtvH+dA4YrxtH3jEZEgWRiwtyBPL0wjz1Kjr5lnOOMsfR7sE1Am+h6DCtpwH21Sg 177YfYHlaOvXI/UpeclTVZH9Pu4wN8mzEt+PXZZ8eW8lTr0ncO45l0DRCy/3090MIcdDAAaLfpUp9 vOefO1rc7/PQMK3Z50vG2CAyf7ZMTvTojsOlYjac7E2omGLWGEd1N+mp8c3uA5UNtH01GCsVz+G6r jK2aWrvOjUBoIOvIwBL8eRu/P4bbCER5PJjRne9drP1D8yxR8jteZYn2kIueR0Q7wZNk+aA4FmTAL +g1nAdhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfgUn-00000007OmJ-1Oig; Tue, 13 Jan 2026 15:39:50 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfgUk-00000007Oll-2tVw for linux-arm-kernel@lists.infradead.org; Tue, 13 Jan 2026 15:39:48 +0000 Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4drD231SJ5zHnGdQ; Tue, 13 Jan 2026 23:39:23 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 63C1A40572; Tue, 13 Jan 2026 23:39:41 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Tue, 13 Jan 2026 15:39:40 +0000 Date: Tue, 13 Jan 2026 15:39:38 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Zeng Heng Subject: Re: [PATCH v3 41/47] arm_mpam: Generate a configuration for min controls Message-ID: <20260113153938.00007d6e@huawei.com> In-Reply-To: <20260112165914.4086692-42-ben.horgan@arm.com> References: <20260112165914.4086692-1-ben.horgan@arm.com> <20260112165914.4086692-42-ben.horgan@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml100012.china.huawei.com (7.191.174.184) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260113_073946_871179_BFF76D03 X-CRM114-Status: GOOD ( 11.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 12 Jan 2026 16:59:08 +0000 Ben Horgan wrote: > From: James Morse > > MPAM supports a minimum and maximum control for memory bandwidth. The > purpose of the minimum control is to give priority to tasks that are below > their minimum value. Resctrl only provides one value for the bandwidth > configuration, which is used for the maximum. > > The minimum control is always programmed to zero on hardware that supports > it. > > Generate a minimum bandwidth value that is 5% lower than the value provided > by resctrl. This means tasks that are not receiving their target bandwidth > can be prioritised by the hardware. > > For component reset reuse the same calculation so that the default is a > value resctrl can set. > > CC: Zeng Heng > Signed-off-by: James Morse > Signed-off-by: Ben Horgan I'm interested to see how this plays out as a default choice vs what people elect to run. Seems harmless to start with this. Reviewed-by: Jonathan Cameron