From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 7D9641F4624 for ; Mon, 3 Mar 2025 23:34:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741044888; cv=none; b=QMA1FFh2h3zfX+rXrVM4Ur/+lxG4T35wvvtfOcaFbsczLQlI+AFeg3tPFAtE//VFhv5gxkK3Iz1LtmsJI/W1cF9Z8Q6tCWzRxJbe9VtItzALKCZgzHdzZOdhBfsUBu/E4L7UTkLk/dvT0GVPLK2pXnCslTt1lCDMNe0oAyINV2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741044888; c=relaxed/simple; bh=/pBvxkD9iITx8Y9QNqYcKLk7D69TTbTyvC7IUFhMawk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=NESOMOd5jfL7tszyGz1i/3qRkFXDAbtWsF15J66mraPfDqAX77ixNyK/tK5sSYW8wbt30I4snXtIu4KJ9I7QZhs5uCMIiZvoYsGUoZL6kAEBf1G1eEfYbgz1HFU2wgJ3sl+jw6/NhTB1fz5HGNr0CgksNZblRkmfS1POp4RE3ro= 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=ThU21PSG; arc=none smtp.client-ip=192.198.163.17 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="ThU21PSG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1741044887; x=1772580887; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=/pBvxkD9iITx8Y9QNqYcKLk7D69TTbTyvC7IUFhMawk=; b=ThU21PSGSU35wjo+fYrLqUsNH/woT3xR0/rufaVmOXgFp9eD9QRhH88+ TT1VmmHJVbKjtofkBFxqi6WXwGKJMfxk7AfEsmzsZXrU1Fq337e0DLMju QEqLSRtvF+HAGbsvD0HSAn7un6W+CgKgdwDSSLN/r3jkZe2JS/LQLY1pk kKa9GMDq6+Cf1lAwDODi+UGcW+7pZTJ3tJclDoMnCeVvEDE1WONHZv3e0 MliTd8UJ+AAgZPtYsuqMRRrsOhZYY6cZV0R8V4yk1yPmuQB2QSndo0wh5 OYcIZ2JeFiHOp+UllPfWibQg+n7MfrCnc+N2r91Hehb6r0E42b/BE/z4P g==; X-CSE-ConnectionGUID: +Iti/sexRUWaTfEXCiyCaw== X-CSE-MsgGUID: TwLtQ0ZETCand25s+6sb+w== X-IronPort-AV: E=McAfee;i="6700,10204,11362"; a="41835895" X-IronPort-AV: E=Sophos;i="6.13,330,1732608000"; d="scan'208";a="41835895" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2025 15:34:46 -0800 X-CSE-ConnectionGUID: 9JBHAOVNRRq7QPF6h0vFRw== X-CSE-MsgGUID: zcQdZxHdTBa2LDL5WVv4rw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,330,1732608000"; d="scan'208";a="117982276" Received: from agluck-desk3.sc.intel.com ([172.25.222.70]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2025 15:33:50 -0800 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [RFC PATCH 00/17] x86/resctrl telemetry monitoring Date: Mon, 3 Mar 2025 15:33:20 -0800 Message-ID: <20250303233340.333743-1-tony.luck@intel.com> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Preamble I'm trying here to provide a picture of the capabilities of telemetry monitoring with a possible resctrl implementation. I'm looking for high level comments on my general approach (especially as it may interact with monitoring features that other architectures may want to add in the future. The first patch in the series just provides a fake copy of the enumeration interface that should show up in the OOBMSM driver in the near future. It allows building, and running, of this series on Intel (and perhaps AMD) systems that don't have h/w support. Background Telemetry features are being implemented in conjunction with the IA32_PQR_ASSOC.RMID value on each logical CPU. This is used to send counts for various events to a collector in a nearby OOMMSM device to be accumulated with counts for each pair received from other CPUs. Cores send event counts when the RMID value changes, or after each 2ms elapsed time. Each OOBMSM device may implement multiple event collectors with each servicing a subset of the logical CPUs on a package. In the initial hardware implementation, there are two categories of events: 1) Energy - Two counters core_energy: This is an estimate of Joules consumed by each core. It is calculated based on the types of instructions executed, not from a power meter. This counter is useful to understand how much energy a workload is consuming. activity: This measures "accumulated dynamic capacitance". Users who want to optimize energy consumption for a workload may use this rather than core_energy because it provides consistent results independent of any frequency or voltage changes that may occur during the runtime of the application (e.g. entry/exit from turbo mode). 2) Performance - Seven counters These are similar events to those available via the Linux "perf" tool, but collected in a way with mush lower overhead (no need to collect data on every context switch). stalls_llc_hit - Counts the total number of unhalted core clock cycles when the core is stalled due to a demand load miss which hit in the LLC c1_res - Counts the total C1 residency across all cores. The underlying counter increments on 100MHz clock ticks unhalted_core_cycles - Counts the total number of unhalted core clock cycles stalls_llc_miss - Counts the total number of unhalted core clock cycles when the core is stalled due to a demand load miss which missed all the local caches c6_res - Counts the total C6 residency. The underlying counter increments on crystal clock (25MHz) ticks unhalted_ref_cycles - Counts the total number of unhalted reference clock (TSC) cycles uops_retired - Counts the total number of uops retired Enumeration The only CPUID based enumeration for this feature is the legacy CPUID(eax=7,ecx=0).ebx{12} that indicates the presence of the IA32_PQR_ASSOC MSR and the RMID field within it. The OOBMSM driver discovers which features are present via PCIe VSEC capabilities. Each feature is tagged with a unique identifier. These identifiers indicate which XML description file from https://github.com/intel/Intel-PMT describes which event counters are available and their layout within the MMIO BAR space of the OOBMSM device. Resctrl User Interface Because there may be multiple OOBMSM collection agents per processor package, resctrl accumulates event counts from all agents on a package and presents a single value to users. This will provide a consistent user interface on future platforms that vary the number of collectors, or the mappings from logical CPUs to collectors. Users will see the legacy monitoring files in the "L3" directories and the telemetry files in "PKG" directories (with each file providing the aggregated value from all OOBMSM collectors on that package). $ tree /sys/fs/resctrl/mon_data/ /sys/fs/resctrl/mon_data/ ├── mon_L3_00 │ ├── llc_occupancy │ ├── mbm_local_bytes │ └── mbm_total_bytes ├── mon_L3_01 │ ├── llc_occupancy │ ├── mbm_local_bytes │ └── mbm_total_bytes ├── mon_PKG_00 │ ├── activity │ ├── c1_res │ ├── c6_res │ ├── core_energy │ ├── stalls_llc_hit │ ├── stalls_llc_miss │ ├── unhalted_core_cycles │ ├── unhalted_ref_cycles │ └── uops_retired └── mon_PKG_01 ├── activity ├── c1_res ├── c6_res ├── core_energy ├── stalls_llc_hit ├── stalls_llc_miss ├── unhalted_core_cycles ├── unhalted_ref_cycles └── uops_retired Resctrl Implementation The OOBMSM driver exposes a function "intel_pmt_get_regions_by_feature()" that returns an array of structures describing the per-RMID groups it found from the VSEC enumeration. Linux looks at the unique identifiers for each group and enables resctrl for all groups with known unique identifiers. The memory map for the counters for each pair is described by the XML file. This is too unwieldy to use in the Linux kernel, so a simplified representation is built into the resctrl code. Note that the counters are in MMIO space instead of accessed using the IA32_QM_EVTSEL and IA32_QM_CTR MSRs. This means there is no need for cross-processor calls to read counters from a CPU in a specific domain. The counters can be read from any CPU. High level description of code changes: 1) New scope RESCTRL_PACKAGE 2) New struct rdt_resource RDT_RESOURCE_INTEL_PMT 3) Refactor monitor code paths to split existing L3 paths from new ones. In some cases this ends up with: switch (r->rid) { case RDT_RESOURCE_L3: helper for L3 break; case RDT_RESOURCE_INTEL_PMT: helper for PKG break; } 4) New source code file "intel_pmt.c" for the code to enumerate, configure, and report event counts. With only one platform providing this feature, it's tricky to tell exactly where it is going to go. I've made the event definitions platform specific (based on the unique ID from the VSEC enumeration). It seems possible/likely that the list of events may change from generation to generation. I've picked names for events based on the descriptions in the XML file. Signed-off-by: Tony Luck Tony Luck (17): x86/rectrl: Fake OOBMSM interface x86/resctrl: Move L3 initialization out of domain_add_cpu_mon() x86/resctrl: Refactor domain_remove_cpu_mon() ready for new domain types x86/resctrl: Split L3 specific code out of rdtgroup_mondata_show() x86/resctrl: Change generic monitor functions to use struct rdt_domain_hdr x86/resctrl: Add and initialize rdt_resource for package scope core monitor x86/resctrl: Prepare for resource specific event ids x86/resctrl: Add initialization hook for Intel PMT events x86/resctrl: Add Intel PMT domain specific code x86/resctrl: Add detailed descriptions for Clearwater Forest events x86/resctrl: Allocate per-package structures for known events x86/resctrl: Add list of known events to RDT_RESOURCE_INTEL_PMT x86/resctrl: Build lookup table for package events x86/resctrl: Add code in rdtgroup_mondata_show() for core monitor events x86/resctrl: Add status files to info/PKG_MON x86/resctrl: Enable package event monitoring x86/resctrl: Update Documentation for package events Documentation/arch/x86/resctrl.rst | 25 +- include/linux/resctrl.h | 11 +- .../cpu/resctrl/fake_intel_pmt_features.h | 72 +++ arch/x86/kernel/cpu/resctrl/internal.h | 51 +- arch/x86/kernel/cpu/resctrl/core.c | 105 ++-- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 82 +-- .../cpu/resctrl/fake_intel_pmt_features.c | 64 +++ arch/x86/kernel/cpu/resctrl/intel_pmt.c | 486 ++++++++++++++++++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 87 +++- arch/x86/Kconfig | 1 + arch/x86/kernel/cpu/resctrl/Makefile | 2 + drivers/platform/x86/intel/pmt/Kconfig | 3 + 12 files changed, 882 insertions(+), 107 deletions(-) create mode 100644 arch/x86/kernel/cpu/resctrl/fake_intel_pmt_features.h create mode 100644 arch/x86/kernel/cpu/resctrl/fake_intel_pmt_features.c create mode 100644 arch/x86/kernel/cpu/resctrl/intel_pmt.c base-commit: 7eb172143d5508b4da468ed59ee857c6e5e01da6 -- 2.48.1