From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (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 D607B372057 for ; Mon, 15 Jun 2026 18:25:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781547920; cv=none; b=aeYiEmGDOg+MHIZJjKQCrZIPm9TJPGS6JhuWg8BLvlWOMHi4giAn0YnLpXaAPNKkiBHMbz9fLfixpMKeFTRePAMlOPSxQDuW3WynwajyKO/fsAic4EmTN2NOSv5DJZw2wVoEFFi02A0SZ4uxkuqU0HAvzeMs+0wiX2YzRLc3XiA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781547920; c=relaxed/simple; bh=lxsJCR217OWgpTb9kVFpj4zf+6hJpTyAdiR9fIcpXPU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iHIu+6tiOzq1FiJ4P6wJ1ZsdH448YLEb5sd/exBV0PlHj0GfYvPmJA6Xpf0G85/MDlq3W+PsH5OfDsDgvb5O8kvBOBWBhetReilXt3F0bRflpQXnLpEJRF76RFno+WvxsWVhSO61D8YqrPzXfZVu0yLKykCuFubSVSuMSOVeGpo= 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=H5LWY/ip; arc=none smtp.client-ip=198.175.65.12 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="H5LWY/ip" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1781547919; x=1813083919; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=lxsJCR217OWgpTb9kVFpj4zf+6hJpTyAdiR9fIcpXPU=; b=H5LWY/ipsDCJg3piVIu0DtDgyezqnwE0HWwq8UI8ioeVdRldtUl65Q44 4XbEsmmGH96uLOjOZsJwfBKwbJnDynqdvfjYwGv4sUD2vhqgmI1Vw1OR7 d5h050Zmh09sQm7TFEEn0RDpqdqJxMXvqVO90cTpMbreFehObzmSmEUIQ Jvq4HjnZJuQUL1kUpnEXOVoE+CnEOF7xD7u2b2/jgU4rOADLcbsSQlWOd Ihxgx4d5ncmo6D2eSqKngKEy8X70YiRDbPN14o6IYT63KH1yiNeKs2/Pl +9H/Ywhg8rPNeswcTGiKq4Uoty9aZV6t495DPRDgsPZEeIuupRLD/UKdH g==; X-CSE-ConnectionGUID: QFN4gNJgTdiwbdWjmjRlpw== X-CSE-MsgGUID: Wf9BRZoARKWaxI2CU2XpDg== X-IronPort-AV: E=McAfee;i="6800,10657,11818"; a="93790065" X-IronPort-AV: E=Sophos;i="6.24,206,1774335600"; d="scan'208";a="93790065" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2026 11:25:13 -0700 X-CSE-ConnectionGUID: UusTBMzJSx6RN6k8E3muKA== X-CSE-MsgGUID: 2DP7jZJGTA6t4ix/TPiR5g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,206,1774335600"; d="scan'208";a="247620670" Received: from spandruv-desk1.amr.corp.intel.com (HELO agluck-desk3.intel.com) ([10.124.221.121]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2026 11:25:13 -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 v8 16/16] Documentation/filesystems/resctrl: Add footnote for telemetry fstab mount caveat Date: Mon, 15 Jun 2026 11:24:57 -0700 Message-ID: <20260615182457.14725-17-tony.luck@intel.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260615182457.14725-1-tony.luck@intel.com> References: <20260615182457.14725-1-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 Add a footnote to the 'If telemetry monitoring is enabled' sentence noting that the PMT driver enumerates telemetry features asynchronously, so an automatic mount of resctrl from /etc/fstab at boot may occur before those features are available, resulting in them not being enabled. The time for enumeration is only a few seconds, so retrying the remount should work. Assisted-by: Claude:Sonnet_4.6 Signed-off-by: Tony Luck --- v8: Added to footnote that a remount should fix Documentation/filesystems/resctrl.rst | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst index b003bed339fd..942194beebc8 100644 --- a/Documentation/filesystems/resctrl.rst +++ b/Documentation/filesystems/resctrl.rst @@ -620,7 +620,7 @@ When monitoring is enabled all MON groups will also contain: each instance of an L3 cache. Each directory contains files for the enabled L3 events (e.g. "llc_occupancy", "mbm_total_bytes", and "mbm_local_bytes"). - If telemetry monitoring is enabled, there will be a "mon_PERF_PKG_YY" + If telemetry monitoring is enabled [#]_, there will be a "mon_PERF_PKG_YY" directory for each physical processor package. Each directory contains files for the enabled telemetry events (e.g. "core_energy". "activity", "uops_retired", etc.) @@ -659,6 +659,11 @@ When monitoring is enabled all MON groups will also contain: returned if the MBM event does not have an assigned counter in the CTRL_MON group nor in any of its associated MON groups. +.. [#] Telemetry features are enumerated asynchronously by the PMT driver. If + resctrl is automatically mounted from ``/etc/fstab`` at boot, the telemetry + features may not yet be available at mount time and will therefore not be + enabled. Remounting a few seconds later should fix this. + "mon_hw_id": Available only with debug option. The identifier used by hardware for the monitor group. On x86 this is the RMID. -- 2.54.0