From nobody Fri Dec 19 21:11:50 2025 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 A00141442ED for ; Tue, 28 May 2024 22:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716934831; cv=none; b=FrwTttjSCLWf4VYdzPmiVk/p9+1GI1ERQTGzYuStpYPHYT0B/ys/OQ4vbzuLDCFDsH/1hk1h5tb9Qszo0Mbhvtm7QApNedGIxlV413tiXHxZXpwK7IuYaiQpYDYPO5PF/ex/S1JMkg01AhoAvl0syZHr7G/54+VD7sCu2CqoVig= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716934831; c=relaxed/simple; bh=MEbLVytHgbRbmQpGtYO+XqR9GjkKAJY7wKHhQb0mGU0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C6o39TLaj6nDL3dxzDvLj/WoS+qhsLZH5GT+EuEaztb/NUZ8vELCbajZU5IYa9Fby053PgAzTUQokwpPjsOnJ6rL1nw/qeNAmAuSFU2nOXiA9CG0C1hQMgDdjupYzgCPL7meLtcEP2moyWpy3Dtzt5qPJQYij0t/jLbxX4q1wPk= 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=kj5rdyzj; arc=none smtp.client-ip=198.175.65.10 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="kj5rdyzj" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1716934830; x=1748470830; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=MEbLVytHgbRbmQpGtYO+XqR9GjkKAJY7wKHhQb0mGU0=; b=kj5rdyzjRJwAtIgU9qhu64IDb7xmB0jdKdg+sKi8T3kkNljmcB6IKPzJ jBNc6RqD2qdG01I+w+Zt47T1AvEiMdloIAv3Oz5H/zgR6AH5Yyo0qRvGs RPCWixG/oWxnAlVVJ02Cut2OCTYWPt4BWhunnXmqQ9yjgU+h8dlzlaIxt 4E6zceQ/omj4rGk8qup+0WE+qe491N7CiDhqV67n1jCJKmcEECL/DsFv6 ZvGvQO6kqYp3aCDcW7Y8AgX/wSE4A3TBgIM6azi4bgXeNm1/LYJvFFSFt UP+Y154IsAzPLnvb+FLFfp1jQkABiO8N86FgbmlNW3OVWNzRuZIlw0xTQ Q==; X-CSE-ConnectionGUID: gl0ZeNWdRo27G+F4VIM2bw== X-CSE-MsgGUID: nTukjUasReO7twZ0o8kITQ== X-IronPort-AV: E=McAfee;i="6600,9927,11085"; a="30812275" X-IronPort-AV: E=Sophos;i="6.08,196,1712646000"; d="scan'208";a="30812275" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2024 15:20:20 -0700 X-CSE-ConnectionGUID: RZgDn3zySHetheQ/gIfjEA== X-CSE-MsgGUID: +eS7IboOT5GvTqmldqgNyw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,196,1712646000"; d="scan'208";a="40090800" Received: from agluck-desk3.sc.intel.com ([172.25.222.70]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2024 15:20:20 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin Cc: x86@kernel.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [PATCH v19 20/20] x86/resctrl: Update documentation with Sub-NUMA cluster changes Date: Tue, 28 May 2024 15:20:05 -0700 Message-ID: <20240528222006.58283-21-tony.luck@intel.com> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240528222006.58283-1-tony.luck@intel.com> References: <20240528222006.58283-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" With Sub-NUMA Cluster mode enabled the scope of monitoring resources is per-NODE instead of per-L3 cache. Suffixes of directories with "L3" in their name refer to Sub-NUMA nodes instead of L3 cache ids. Users should be aware that SNC mode also affects the amount of L3 cache available for allocation within each SNC node. Signed-off-by: Tony Luck --- Documentation/arch/x86/resctrl.rst | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/re= sctrl.rst index 627e23869bca..401f6bfb4a3c 100644 --- a/Documentation/arch/x86/resctrl.rst +++ b/Documentation/arch/x86/resctrl.rst @@ -375,6 +375,10 @@ When monitoring is enabled all MON groups will also co= ntain: all tasks in the group. In CTRL_MON groups these files provide the sum for all tasks in the CTRL_MON group and all tasks in MON groups. Please see example section for more details on usage. + On systems with Sub-NUMA (SNC) cluster enabled there are extra + directories for each node (located within the "mon_L3_XX" directory + for the L3 cache they occupy). These are named "mon_sub_L3_YY" + where "YY" is the node number. =20 "mon_hw_id": Available only with debug option. The identifier used by hardware @@ -484,6 +488,19 @@ if non-contiguous 1s value is supported. On a system w= ith a 20-bit mask each bit represents 5% of the capacity of the cache. You could partition the cache into four equal parts with masks: 0x1f, 0x3e0, 0x7c00, 0xf8000. =20 +Notes on Sub-NUMA Cluster mode +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D +When SNC mode is enabled, Linux may load balance tasks between Sub-NUMA +nodes much more readily than between regular NUMA nodes since the CPUs +on Sub-NUMA nodes share the same L3 cache and the system may report +the NUMA distance between Sub-NUMA nodes with a lower value than used +for regular NUMA nodes. +The top-level monitoring files in each "mon_L3_XX" directory provide +the sum of data across all SNC nodes sharing an L3 cache instance. +Users who bind tasks to the CPUs of a specific Sub-NUMA node can read +the "llc_occupancy", "mbm_total_bytes", and "mbm_local_bytes" in the +"mon_sub_L3_YY" directories to get node local data. + Memory bandwidth Allocation and monitoring =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 --=20 2.45.0