From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 4C7774E06E9 for ; Wed, 16 Sep 2026 23:13:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789600426; cv=none; b=rPM9kURgWnxkLT0MgA/RgrRdnrVLiDvKOZ+82RS5PME1x9FwSXNvc5/i/ZShjZx9T6iYcZPMevFhjoeT/it2px8FMpS9uvSf278DycOwkyrdZL84zRlcPZBf6jIFDHUAbYhAc6eXq0B9tPBgBhu8MPl9XJwDo8pBHesLn6RBDFw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789600426; c=relaxed/simple; bh=AOTgnRzzoC8PIhxgcqVQ7yQ+PJ606+1nZeY+ZVMUtPE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SMq1fNrtLNm5F0E18QX5ByDFnPoCT2rdbVFFxk5gAYpgd/8uP+LohnUdmRnlH/J/SnTe1ZnH7YaShE66DS+BcZYVqQbRQYSh5vylJTolGZ+pPTGCr6KewWAoQL90l8n03IWx6F+ZrF7AT9qCQ6jg8xSO9fH9399QDE839GfwoDI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=OB/hgLst; arc=none smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="OB/hgLst" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789600424; x=1821136424; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=AOTgnRzzoC8PIhxgcqVQ7yQ+PJ606+1nZeY+ZVMUtPE=; b=OB/hgLstu+/oQKMDqqW1eprsF3H8Oe2AMZXRW9wst0k5ryv+mhZU2v9Q /rKdQ0YzgbivxIxSEeqiS/CGYHtkDlPM6/ekiQjrFLiYDIG/XYG7NZHfc 7KhDuvrNNlDCPY7pNxmR7et6gInlfx129RBLIs4+SkBTa2rYSfzDMRRTF OTDMWXu8xbkoV93jhyht7etr3Ya68sAy+IJ9XA+iHzaU/x6WBr2LZ2lUr AvPhXu6G2ILRKvxiPxWzZA4gU/Wv0X+O64QdiNpUYx6ASfgXj8GZXS8EF FWe20Wi6F/us66B6mFeMoi+AP8qDke8WQAoc79o4xq8oGB62wNJmIDtRT A==; X-CSE-ConnectionGUID: m5JeQxeRQsWAeqYuMaoLng== X-CSE-MsgGUID: 5yoKQdPJTRSJT/rnZvR7Mg== X-IronPort-AV: E=McAfee;i="6800,10657,11905"; a="93861414" X-IronPort-AV: E=Sophos;i="6.27,103,1787036400"; d="scan'208";a="93861414" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2026 16:13:35 -0700 X-CSE-ConnectionGUID: L+oIe3ktQY66zA0YI57MkQ== X-CSE-MsgGUID: UeYhN7QdSWONac7nIkK10A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,103,1787036400"; d="scan'208";a="277231462" Received: from khuang2-desk.gar.corp.intel.com (HELO agluck-desk3.home.arpa) ([10.124.223.219]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2026 16:13:35 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin , Chen Yu , David E Box , x86@kernel.org Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [PATCH v12 11/25] fs/resctrl: Add interface to disable a monitor event Date: Wed, 16 Sep 2026 16:13:06 -0700 Message-ID: <20260916231320.14502-12-tony.luck@intel.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260916231320.14502-1-tony.luck@intel.com> References: <20260916231320.14502-1-tony.luck@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit resctrl currently assumes all monitor events are enabled before any domain is created, because per-domain state is allocated by the architecture's CPU hotplug callbacks. There is no way to disable an event once registered. AET events are enumerated by the INTEL_PMT_TELEMETRY driver. To allow that driver to be a loadable module, resctrl must tolerate AET events appearing and disappearing, which requires the ability to disable an event when the driver is unloaded. Add resctrl_disable_mon_event(). The architecture owns domain lifetime and knows mount state, so it is responsible for calling this only while resctrl is unmounted and for cleaning up any per-domain state. Document those requirements in the kerneldoc since they are not enforced in code. Signed-off-by: Tony Luck Reviewed-by: Reinette Chatre --- v12: Added Reinette RB tag (from v10 review). Better header comment for resctrl_disable_mon_event(). --- include/linux/resctrl.h | 34 ++++++++++++++++++++++++++++++++++ fs/resctrl/monitor.c | 15 +++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 6b07ac2c8675..fbf737e884db 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -449,9 +449,43 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); u32 resctrl_arch_system_num_rmid_idx(void); int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); +/** + * resctrl_enable_mon_event() - Enable monitoring event + * @eventid: ID of the event + * @any_cpu: True if event data can be read from any CPU. + * @binary_bits: Number of binary places of the fixed-point value expected to + * back a floating point event. Can only be set for floating point + * events. + * @arch_priv: Architecture private data associated with event. Passed back to + * architecture when reading the event via resctrl_arch_rmid_read(). + * + * The file system must not be mounted when enabling an event. + * + * Events that require per-domain (architectural and/or filesystem) state must + * be enabled before the domain structures are allocated. For example before + * CPU hotplug callbacks that allocate domain structures are registered. If the + * architecture discovers a resource after initialization it should enable + * events needing per-domain state before any domain structure allocation which + * should be coordinated with the CPU hotplug callbacks. + * + * Return: + * true if event was successfully enabled, false otherwise. + */ bool resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu, unsigned int binary_bits, void *arch_priv); +/** + * resctrl_disable_mon_event() - Disable monitoring event + * @eventid: ID of the event + * + * Never disable an event that may be accessed while the file system is unmounted. + * + * Events that require per-domain (architectural and/or filesystem) state + * will require additional cleanup which should be coordinated with the CPU + * hotplug callbacks. + */ +void resctrl_disable_mon_event(enum resctrl_event_id eventid); + bool resctrl_is_mon_event_enabled(enum resctrl_event_id eventid); bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt); diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index 02e81fc82b14..2a28fe04284b 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -1066,6 +1066,21 @@ bool resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu, return true; } +void resctrl_disable_mon_event(enum resctrl_event_id eventid) +{ + if (WARN_ON_ONCE(eventid < QOS_FIRST_EVENT || eventid >= QOS_NUM_EVENTS)) + return; + if (!mon_event_all[eventid].enabled) { + pr_warn("Event %d already disabled\n", eventid); + return; + } + + mon_event_all[eventid].any_cpu = false; + mon_event_all[eventid].binary_bits = 0; + mon_event_all[eventid].arch_priv = NULL; + mon_event_all[eventid].enabled = false; +} + bool resctrl_is_mon_event_enabled(enum resctrl_event_id eventid) { return eventid >= QOS_FIRST_EVENT && eventid < QOS_NUM_EVENTS && -- 2.55.0