From nobody Fri Dec 19 06:02:54 2025 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 5230016D9D0 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=1715811828; cv=none; b=j/EmMwjjhLpPPu3kRdC1lVeLQYgAYpIOBObPuPcLWtYrq9qflM6LYcV9OMTwL3LUWo2v59/iX4t4MGqLDfx92rs4Le0gz9XbpZZMCfV9h6i9bPZEx8MJrOeXqFH6r2rHmmR9tGPC18RMudoHgQykTBuNpjxfFoi1AdScVSgAcWs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715811828; c=relaxed/simple; bh=qTA6gl03vEuZNwR+0yktOI8EhYVtmjYM4Gw1yRj+4sA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=l3D2PoveVTdul8cJ7Z5McI6ion60pdy+Gq/gVyqlbYQRg653PtIJ1aOHIQY5gvlfDlwU1wNhgstC4TtOte6d5UKzBL2jBnd7BsTKcrtLkN1xyWn/Nk9Zh5K6cIG0TBFKk5HjG04Nm5A+qYHB8/+1IHONKiEsYeBx8ruXVuUyalU= 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=mY9bkmPR; 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="mY9bkmPR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715811826; x=1747347826; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qTA6gl03vEuZNwR+0yktOI8EhYVtmjYM4Gw1yRj+4sA=; b=mY9bkmPRMdteDAVtziNFHiPZZNJ9SpVtJG/OUbnP8dXQuS3ZL10kIF8O WINl+OaBUkxlBB2kINUeD5hzvtpd71vWxXapeaksyman/YJtkVF0vOA6M xl4Vfd1ZOOFuK/iSkODUZeRw5bEw36vz0jpL7VtWXT1g4ROpBAMXHEN28 ySmfR8DpKGnVn06HZ/4TrUPr90nQJG98RCxoZlsXyYOOjP5n2trtrIoMi xL56UIfcTjQWhgKlNnuTfEMPPu7tuAlsDERuIFYeMhqXdmdbOWlUW5jsH Lnqfk2IQlA426t65gcYCsDbZngbXePoJPanWkVk3jzKKhu/ezZeYkZ7VB w==; X-CSE-ConnectionGUID: 6xtp+7jJREiPDRzMlwnCUw== X-CSE-MsgGUID: CbNFrj17QsWT/Pzp8lg/pA== X-IronPort-AV: E=McAfee;i="6600,9927,11074"; a="15671749" X-IronPort-AV: E=Sophos;i="6.08,162,1712646000"; d="scan'208";a="15671749" 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: 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" *** 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/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 2.44.0