From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C68302DA776 for ; Mon, 5 Jan 2026 17:06:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767632807; cv=none; b=qb8KWvZo9YCPADMnNDcNxyC8dCnGcXXUfrgwnJQTpKHISzHewLSBf7TKirSHMak9Zl57lUZ8UqPjpRzGABNvCAE3m5O6p+QKKjfNGFl9q+WQYfp6ElKN4TChzIGUrpKCI/i04hTP9/ydzmw8dq/8dMiTnPdNvhWMduomXxnkAAA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767632807; c=relaxed/simple; bh=Nr2ItRKOV1gkTtre9RNf4EDCKnlLKnhuDrdnm7tfnvU=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=KZ3QrqqQ6g+iZnfaCM1iqxlFxbgu8yVhgpLBruIg4hOitEIBg7XJyTRMQ/UqNuYKQeXKFHYwwnZyaXTqilZ0LvZ+jBKxLvRQXC3SUG5JTXiEl4KSig/8lIYr/uomUaSuqukSEbsmMl7WeFkKTed54kQOD/Z6EC7cQJe6UXcEL9E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dlLLS30BnzHnGhY; Tue, 6 Jan 2026 01:06:40 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id F1BE140086; Tue, 6 Jan 2026 01:06:42 +0800 (CST) Received: from localhost (10.126.174.38) 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; Mon, 5 Jan 2026 17:06:41 +0000 Date: Mon, 5 Jan 2026 17:06:39 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 08/45] arm64: mpam: Re-initialise MPAM regs when CPU comes online Message-ID: <20260105170639.00007c1a@huawei.com> In-Reply-To: <20251219181147.3404071-9-ben.horgan@arm.com> References: <20251219181147.3404071-1-ben.horgan@arm.com> <20251219181147.3404071-9-ben.horgan@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500012.china.huawei.com (7.191.174.4) To dubpeml100005.china.huawei.com (7.214.146.113) On Fri, 19 Dec 2025 18:11:10 +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. > > Signed-off-by: James Morse > Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron