From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DE47B33EC; Wed, 18 Mar 2026 10:22:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773829364; cv=none; b=VRFUf97HoYHHbrd3nhuO699LTDmLV/6FZi/q+azsRuCOBaPsm2BMCk6AZFS4qYiLWyA2cTKvJYnfoE7q/5AKgVfPp7R0JgcBuyjItdSTIKqjUATA47COphpARyv01bp3NRAq9HKYI30UWaE9JDUdpH85W0Ki3WF5cioo/DzxWDk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773829364; c=relaxed/simple; bh=AWNoVGlTeHh0vTJZXksAKLtoa+rNN0yOAW8HDTelPtI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QcJ8gI/yYC+/zlNJVEQHLnU1mmnSQVWQTuGtUjzyCjfjkHKK/n7Lw8OT847dtPH7vu9h5DmbZcZdks8E/61Sr2hPDOXZ4ol3ysK6Cz9Cmn6SS+bkfYHJALGPEb8Uzp5sUJCDACx5R6IK7ckdhi2m15z4WuhbUGVCjHmIhbQ0uCA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E5FC81E2F; Wed, 18 Mar 2026 03:22:35 -0700 (PDT) Received: from [10.1.196.46] (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3BEF93F778; Wed, 18 Mar 2026 03:22:38 -0700 (PDT) Message-ID: <967c7d65-6ffe-4eb9-817c-2eb1f9b510b1@arm.com> Date: Wed, 18 Mar 2026 10:22:36 +0000 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Thunderbird Daily Subject: Re: [PATCH v6 00/40] arm_mpam: Add KVM/arm64 and resctrl glue code To: Jesse Chick Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, zengheng4@huawei.com, linux-doc@vger.kernel.org References: <20260313144617.3420416-1-ben.horgan@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Jesse, On 3/17/26 00:25, Jesse Chick wrote: > Hi Ben, > > >> Thanks for all the reviewing and testing so far. Just a bit more to get this >> over the line. > > > I tested this patch series, specifically L3 CPOR, on an Ampere > implementation with common benchmarking tools (lmbench, multichase). > > >> Generally the resctrl glue code works by picking what MPAM features it can expose >> from the MPAM drive, then configuring the structs that back the resctrl helpers. >> If your platform is sufficiently Xeon shaped, you should be able to get L2/L3 CPOR >> bitmaps exposed via resctrl. CSU counters work if they are on/after the L3. MBWU >> counters are considerably more hairy, and depend on hueristics around the topology, >> and a bunch of stuff trying to emulate ABMC. > > > The observed latency in increasingly large R/W operations scaled as > expected across various numbers of competing processes and cache > portions. The distinct jumps in latency as successive cache level > capacities were exceeded indicates that (a) L3 CPOR is configurable from > user space via the resctrl interface as described in this series and (b) > that the feature itself is working correctly. > > For the series: > > Tested-by: Jesse Chick Thanks for the testing and description. Ben > > Thanks, > Jesse > >