From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 EAF6916F296 for ; Wed, 15 May 2024 22:23:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715811831; cv=none; b=F9WVLNpYCsiRfNGFjgHDEynhWWb93CECFdSFuIu2pTqDAc/uumJgbUGtR+JtXq70wc5yjbQ6iG11nsnWrWcigc20zZ2JkM7PDjFPfZIPyyadulsmiEHCoI/GU/fSbZw27P2UDOBMNlLW2owLhA+TK1OKQdYtCj+jts0HJued/94= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715811831; c=relaxed/simple; bh=qTA6gl03vEuZNwR+0yktOI8EhYVtmjYM4Gw1yRj+4sA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CE7fyGlyaF9BRo/sNldQ0j2Mis6iRH+qQFXxSeMdixKb6qO4zTgj4CzAAoNVu+EBwQMwvKpbFfYgKHk+GMT0EZQkzRTvuzCDaopVb8ymSN4Mtwm+RkLayJkhAo0gXNF2Gueg3ONYDzF/f9HSJQqWnoxm4RTFxyuNS3aJwJcHpd8= 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=iC+U5IZs; arc=none smtp.client-ip=198.175.65.15 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="iC+U5IZs" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715811827; x=1747347827; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qTA6gl03vEuZNwR+0yktOI8EhYVtmjYM4Gw1yRj+4sA=; b=iC+U5IZsx3EKg5OjWMoYJDL4XjOpvS+LtnUdRdUvSzJMenbMN7Mfmb0Z sNYkF79ak23IWOyv6UKckRMK/HKeEGKfSkfOyIgu9oKMb6Qni7WmcuLg9 oYDasxXm8mE5yLRzEToO4W8D7N1yxd3wtizQ74r/OGYbNc6X8DTSCOjgB +kJz/a3JuUw4niG//7Sty6nDK9Mceplm4dfATATSSP828EabpF2+vMpFj 797xUunQ46oSPkTBDa/qpbd2jyAlSvztjffF1ir5x4x790B+KG+UsIGwL WkraLX7xj+YPxuSYNzInWzGaia3OshDntM7chSdaD1dmFcpyoTPgTQiDH g==; X-CSE-ConnectionGUID: 9SY9MnDCSfqK5SvVssGvCA== X-CSE-MsgGUID: kft2xuOhQl+EgsSl+z2r2w== X-IronPort-AV: E=McAfee;i="6600,9927,11074"; a="15671750" X-IronPort-AV: E=Sophos;i="6.08,162,1712646000"; d="scan'208";a="15671750" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 May 2024 15:23:37 -0700 X-CSE-ConnectionGUID: gPDEvwLEQNusl5AbC9hXqw== X-CSE-MsgGUID: yyvEtaVQTBO97Tpx2we+jA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,162,1712646000"; d="scan'208";a="35989202" Received: from agluck-desk3.sc.intel.com ([172.25.222.105]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 May 2024 15:23:37 -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 v18 17/17] x86/resctrl: Update documentation with Sub-NUMA cluster changes Date: Wed, 15 May 2024 15:23:25 -0700 Message-ID: <20240515222326.74166-18-tony.luck@intel.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240515222326.74166-1-tony.luck@intel.com> References: <20240515222326.74166-1-tony.luck@intel.com> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit *** This patch needs updating for new files for monitoring *** 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/resctrl.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 contain: 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. "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 with 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. +Notes on Sub-NUMA Cluster mode +============================== +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 ========================================== -- 2.44.0