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 BC455ECD981 for ; Thu, 5 Feb 2026 16:20:52 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=r5rQdE5T9qbmhnzprOOe/wAIrsJp3cap5DTTM0INxII=; b=gUB9Ykw1ABlWHg0d6+S9kxuh0W Sj5twBMjg7VoDZiRfY+CLYmXin9br30RChQU3uPY+/WYf8J85FhlPhVgQNz4eu4VG2P3lwVTZ6BWl oBKs/PoUqM1uc9caLO/JtWJ2e14ktkQG8fSB6+8EG5oZRGCMzU6e40zELxbLfUC+ekyNfnKJduovG OkRb70B8nNVgQ4nmSDrLgfh3vjeWKz7F6s7Axwh+Mq2t65Ni0JDHpAU1JMlm0DrG6qe2oIIXuDFQD Ly4nbej10VbNaAtxmpLcMQVY68LhAoL3WgqjMLzn/zQIoG9xjxrg21x6Yz8h60q1genSrSKQIdO3m A+rr/3mQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vo263-0000000ADsf-05Fh; Thu, 05 Feb 2026 16:20:47 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vo25z-0000000ADsI-45ca for linux-arm-kernel@lists.infradead.org; Thu, 05 Feb 2026 16:20:45 +0000 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 EC098339; Thu, 5 Feb 2026 08:20:35 -0800 (PST) Received: from arm.com (arrakis.cambridge.arm.com [10.1.197.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 85D6C3F632; Thu, 5 Feb 2026 08:20:36 -0800 (PST) Date: Thu, 5 Feb 2026 16:20:33 +0000 From: Catalin Marinas To: Ben Horgan 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, 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, Shaopeng Tan Subject: Re: [PATCH v4 05/41] arm64: mpam: Re-initialise MPAM regs when CPU comes online Message-ID: References: <20260203214342.584712-1-ben.horgan@arm.com> <20260203214342.584712-6-ben.horgan@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260203214342.584712-6-ben.horgan@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260205_082044_049681_BEF62BDB X-CRM114-Status: GOOD ( 12.23 ) 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 Tue, Feb 03, 2026 at 09:43:06PM +0000, Ben Horgan wrote: > From: James Morse > > Now that the MPAM system registers are expected to have values that change, > reprogram them based on the previous value when a CPU is brought online. > > Previously MPAM's 'default PARTID' of 0 was always used for MPAM in > kernel-space as this is the PARTID that hardware guarantees to > reset. Because there are a limited number of PARTID, this value is exposed > to user-space, meaning resctrl changes to the resctrl default group would > also affect kernel threads. Instead, use the task's PARTID value for > kernel work on behalf of user-space too. The default of 0 is kept for both > user-space and kernel-space when MPAM is not enabled. > > Tested-by: Gavin Shan > Tested-by: Shaopeng Tan > Tested-by: Peter Newman > Reviewed-by: Jonathan Cameron > Signed-off-by: James Morse > Reviewed-by: Gavin Shan > Signed-off-by: Ben Horgan Reviewed-by: Catalin Marinas