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SkylakeSP

Thomas Gruber edited this page Nov 16, 2020 · 7 revisions

Architecture specific notes for Intel® Skylake X

Performance groups

Intel® Skylake X Performance groups

Events

The input file for the events on Intel® Skylake X can be found here.

Counters

Core-local counters

Fixed-purpose counters

Since the Core2 microarchitecture, Intel® provides a set of fixed-purpose counters. Each can measure only one specific event.

Counters
Counter name Event name
FIXC0 INSTR_RETIRED_ANY
FIXC1 CPU_CLK_UNHALTED_CORE
FIXC2 CPU_CLK_UNHALTED_REF
Available Options
Option Argument Description Comment
anythread N Set bit 2+(index*4) in config register
kernel N Set bit (index*4) in config register

General-purpose counters

The Intel® Skylake X microarchitecture provides 4-8 general-purpose counters consisting of a config and a counter register.

Counters
Counter name Event name
PMC0 *
PMC1 *
PMC2 *
PMC3 *
PMC4 * (only available without HyperThreading)
PMC5 * (only available without HyperThreading)
PMC6 * (only available without HyperThreading)
PMC7 * (only available without HyperThreading)
Available Options
Option Argument Description Comment
edgedetect N Set bit 18 in config register
kernel N Set bit 17 in config register
anythread N Set bit 21 in config register
threshold 8 bit hex value Set bits 24-31 in config register
invert N Set bit 23 in config register
in_transaction N Set bit 32 in config register Only available if Intel® Transactional Synchronization Extensions are available
in_transaction_aborted N Set bit 33 in config register Only counter PMC2 and only if Intel® Transactional Synchronization Extensions are available
Special handling for events

The Intel® Skylake X microarchitecture provides measureing of offcore events in PMC counters. Therefore the stream of offcore events must be filtered using the OFFCORE_RESPONSE registers. The Intel® Skylake microarchitecture has two of those registers. LIKWID defines some events that perform the filtering according to the event name. Although there are many bitmasks possible, LIKWID natively provides only the ones with response type ANY. Own filtering can be applied with the OFFCORE_RESPONSE_0_OPTIONS and OFFCORE_RESPONSE_1_OPTIONS events. Only for those events two more counter options are available:

Option Argument Description Comment
match0 16 bit hex value Input value masked with 0x8FFF and written to bits 0-15 in the OFFCORE_RESPONSE register Check the Intel® Software Developer System Programming Manual, Vol. 3, Chapter Performance Monitoring and https://download.01.org/perfmon/SKL.
match1 22 bit hex value Input value is written to bits 16-37 in the OFFCORE_RESPONSE register Check the Intel® Software Developer System Programming Manual, Vol. 3, Chapter Performance Monitoring and https://download.01.org/perfmon/SKL.

Thermal counter

The Intel® Skylake X microarchitecture provides one register for the current core temperature.

Counters
Counter name Event name
TMP0 TEMP_CORE

Socket-wide counters

Energy counters

The Intel® Skylake X microarchitecture provides measurements of the current energy consumption through the RAPL interface.

Counters
Counter name Event name
PWR0 PWR_PKG_ENERGY
PWR1 PWR_PP0_ENERGY
PWR2 PWR_PP1_ENERGY
PWR3 PWR_DRAM_ENERGY

Last Level cache counters

The Intel® Skylake X microarchitecture provides measurements of the LLC coherency engine in the uncore. The description from Intel®:
The LLC coherence engine and Home agent (CHA) merges the caching agent and home agent (HA) responsibilities of the chip into a single block. In its capacity as a caching agent the CHA manages the interface between the core the IIO devices and the last level cache (LLC). In its capacity as a home agent the CHA manages the interface between the LLC and the rest of the UPI coherent fabric as well as the on die memory controller.
The LLC hardware performance counters are exposed to the operating system through the MSR interface. The maximal amount of supported coherency engines for the Intel® Skylake X microarchitecture is 28. It may be possible that your systems does not have all CBOXes, LIKWID will skip the unavailable ones in the setup phase. The name CBOX originates from the Nehalem EX uncore monitoring.

Counters
Counter name Event name
CBOX<0-27>C0 *
CBOX<0-27>C1 *
CBOX<0-27>C2 *
CBOX<0-27>C3 *
Available Options
Option Argument Operation Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 8 bit hex value Set bits 24-31 in config register
tid 9 bit hex value Set bits 0-8 in MSR_UNC_C<0-27>_PMON_BOX_FILTER register and bit 19 in the config register Bits 0-2 specify the thread, bits 3-8 the core. LIKWID 5.0 used wrongly an 8 bit hex value in bits 0-7.
state 10 bit hex value Set bits 17-26 in MSR_UNC_C<0-27>_PMON_BOX_FILTER register LLC F: 0x80,
LLC M: 0x40,
LLC E: 0x20,
LLC S: 0x10,
SF H: 0x08,
SF E: 0x04,
SF S: 0x02,
LLC I: 0x01
opcode 20 bit hex value Set bits 9-28 in MSR_UNC_C<0-27>_PMON_BOX_FILTER1 register A list of valid opcodes can be found in the Intel® Xeon SP uncore Manual, section 3.1.1. Bits 17,18 and 27,28 must be all 1. Is set by LIKWID.
match0 2 bit hex address Set bits 30-31 in MSR_UNC_C<0-27>_PMON_BOX_FILTER1 register See the Intel® Xeon SP uncore Manual for more information.
match1 6 bit hex value with filter mask 0x33 Set bits 0-5 in MSR_UNC_C<0-27>_PMON_BOX_FILTER1 register See the Intel® Xeon SP uncore Manual for more information.
Special handling for events

The Intel® Skylake X microarchitecture provides an event LLC_LOOKUP which can be filtered with the 'state' option. If no 'state' is set, LIKWID sets the state to 0x3FF, the default value to measure all lookups.

Uncore management fixed-purpose counter

The Intel® Skylake X microarchitecture provides measurements of the management box in the uncore. The description from Intel®:
The UBox serves as the system configuration controller for Intel® Xeon® Processor Scalable Memory Family
In this capacity, the UBox acts as the central unit for a variety of functions:

  • The master for reading and writing physically distributed registers across using the Message Channel.
  • The UBox is the intermediary for interrupt traffic, receiving interrupts from the system and dispatching interrupts to the appropriate core.
  • The UBox serves as the system lock master used when quiescing the platform (e.g., Intel® UPI bus lock).

The single fixed-purpose counter counts the clock frequency of the clock source of the uncore. The uncore management performance counters are exposed to the operating system through the MSR interface. The name UBOX originates from the Nehalem EX uncore monitoring.

Counter
Counter name Event name
UBOXFIX UNCORE_CLOCK

Uncore management general-purpose counters

The Intel® Skylake X microarchitecture provides measurements of the management box in the uncore. The description from Intel®:
The UBox serves as the system configuration controller for Intel® Xeon® Processor Scalable Memory Family
In this capacity, the UBox acts as the central unit for a variety of functions:

  • The master for reading and writing physically distributed registers across using the Message Channel.
  • The UBox is the intermediary for interrupt traffic, receiving interrupts from the system and dispatching interrupts to the appropriate core.
  • The UBox serves as the system lock master used when quiescing the platform (e.g., Intel® UPI bus lock).

The uncore management performance counters are exposed to the operating system through the MSR interface. The name UBOX originates from the Nehalem EX uncore monitoring.

Counter
Counter name Event name
UBOX0 *
UBOX1 *
Available Options
Option Argument Operation Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 5 bit hex value Set bits 24-28 in config register

Power control unit fixed-purpose counters

The Intel® Skylake X microarchitecture provides measurements of the power control unit (PCU) in the uncore. The description from Intel®:
The PCU is the primary Power Controller for the Intel® Xeon® Processor Scalable Memory Family die, responsible for distributing power to core/uncore components and thermal management. It runs in firmware on an internal micro-controller and coordinates the socket’s power states.
Note: Many power saving features are tracked as events in their respective units. For example, Intel® QPI Link Power saving states and Memory CKE statistics are captured in the Intel® QPI Perfmon and IMC Perfmon respectively.

The PCU offers four fixed-purpose counters to retrieve the cycles CPU cores stay in state C6, C3, P6 and P3. The uncore management performance counters are exposed to the operating system through the MSR interface. The name WBOX originates from the Nehalem EX uncore monitoring.

Counters
Counter name Event name
WBOX0FIX CORES_IN_C3
WBOX1FIX CORES_IN_C6
WBOX2FIX CORES_IN_P3
WBOX3FIX CORES_IN_P6

Power control unit general-purpose counters

The Intel® Skylake X microarchitecture provides measurements of the power control unit (PCU) in the uncore. The description from Intel®:
The PCU is the primary Power Controller for the Intel® Xeon® Processor Scalable Memory Family die, responsible for distributing power to core/uncore components and thermal management. It runs in firmware on an internal micro-controller and coordinates the socket’s power states.
Note: Many power saving features are tracked as events in their respective units. For example, Intel® QPI Link Power saving states and Memory CKE statistics are captured in the Intel® QPI Perfmon and IMC Perfmon respectively.

The PCU performance counters are exposed to the operating system through the MSR interface. The name WBOX originates from the Nehalem EX uncore monitoring.

Counters
Counter name Event name
WBOX0 *
WBOX1 *
WBOX2 *
WBOX3 *
Available Options
Option Argument Operation Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 5 bit hex value Set bits 24-28 in config register
occupancy_filter 32 bit hex value Set bits 0-31 in
MSR_UNC_PCU_PMON_BOX_FILTER register
Band0: bits 0-7,
Band1: bits 8-15,
Band2: bits 16-23,
Band3: bits 24-31
occupancy 2 bit hex value Set bit 14-15 in config register Cores
in C0: 0x1,
in C3: 0x2,
in C6: 0x3
occ_edgedetect N Set bit 31 in config register
occ_invert N Set bit 30 in config register

Memory controller fixed-purpose counters

The Intel® Skylake X microarchitecture provides measurements of the integrated Memory Controllers (iMC) in the uncore. The description from Intel®:
The Intel® Xeon® Processor Scalable Memory Family integrated Memory Controller provides the interface to DRAM and communicates to the rest of the Uncore through the Mesh2Mem block.
The memory controller also provides a variety of RAS features, such as ECC, lockstep, memory access retry, memory scrubbing, thermal throttling, mirroring, and rank sparing.

The integrated Memory Controllers performance counters are exposed to the operating system through PCI interfaces. There may be two memory controllers in the system. There are four different PCI devices per memory controller, each covering one memory channel. Each channel has one fixed counter for the DRAM clock. The four channels of the first memory controller are MBOX0-3, the four channels of the second memory controller (if available) are named MBOX4-7. The name MBOX originates from the Nehalem EX uncore monitoring.

Counters
Counter name Event name
MBOX<0-7>FIX DRAM_CLOCKTICKS

Memory controller general-purpose counters

The Intel® Skylake X microarchitecture provides measurements of the integrated Memory Controllers (iMC) in the uncore. The description from Intel®:
The Intel® Xeon® Processor Scalable Memory Family integrated Memory Controller provides the interface to DRAM and communicates to the rest of the Uncore through the Mesh2Mem block.
The memory controller also provides a variety of RAS features, such as ECC, lockstep, memory access retry, memory scrubbing, thermal throttling, mirroring, and rank sparing.

The integrated Memory Controllers performance counters are exposed to the operating system through PCI interfaces. There may be two memory controllers in the system. There are four different PCI devices per memory controller, each covering one memory channel. Each channel has four different general-purpose counters. The four channels of the first memory controller are MBOX0-3, the four channels of the second memory controller (if available) are named MBOX4-7. The name MBOX originates from the Nehalem EX uncore monitoring.

Counters
Counter name Event name
MBOX<0-7>C0 *
MBOX<0-7>C1 *
MBOX<0-7>C2 *
MBOX<0-7>C3 *
Available Options
Option Argument Operation Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 8 bit hex value Set bits 24-31 in config register

UPI Link Layer counters

The Intel® Skylake X microarchitecture uses a new intersocket communication network. The name changed from QPI to UPI. The description from Intel®:
Intel® Xeon® Processor Scalable Memory Family uses a new coherent interconnect for scaling to multiple sockets known as Intel® Ultra Path Interconnect (Intel UPI). Intel® UPI technology provides a cache coherent socket to socket external communication interface between processors. The processor implements 2 Intel® UPI links on -EP or 3 Intel® UPI links on -EX. Figures below show a 2-socket or 4-socket server systems, as examples. Intel® UPI is also used as a coherent communication interface between processors and OEM 3rd party Node Controllers (XNC). The SBOX hardware performance counters are exposed to the operating system through PCI devices. There are 3 possible links, each providing three general-purpose counters. The name SBOX was first used in Nehalem architectures.
Description from Intel®: There are two Intel® UPI agents that share a single mesh stop and a third agent in the EX part with its own mesh stop. These links can be connected to a single destination (such as in DP), or can be connected to two separate destinations (4s Ring or sDP). Therefore, it will be necessary to count Intel® UPI statistics for each agent separately.

Counters
Counter name Event name
SBOX<0-2>C0 *
SBOX<0-2>C1 *
SBOX<0-2>C2 *
SBOX<0-2>C3 *
Available Options
Option Argument Description Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 8 bit hex value Set bits 24-31 in config register
nid 4 bit hex value Set bits 40-43 in config register and mandatory bit 45 Note: Node 0 has value 0x1
match0 8 bit hex address Set bits 32-39 in config register See the Intel® Xeon® Processor Scalable Family Uncore Reference Manual for more information.
match1 10 bit hex address Set bits 46-55 in config register See the Intel® Xeon® Processor Scalable Family Uncore Reference Manual for more information.

M3UPI counters

The Intel® Skylake X microarchitecture uses a new intrasocket communication network. Instead of a ring topology it uses now a mesh topology. The description from Intel®:
M3UPI is the interface between the mesh and the Intel® UPI Link Layer. It is responsible for translating between mesh protocol packets and flits that are used for transmitting data across the Intel® UPI interface. It performs credit checking between the local Intel® UPI LL, the remote Intel® UPI LL and other agents on the local mesh. The RBOX hardware performance counters are exposed to the operating system through PCI devices. There are up to 3 devices, each providing three general-purpose counters. The name RBOX was first used in Nehalem architectures.

Counters
Counter name Event name
RBOX<0-2>C0 *
RBOX<0-2>C1 *
RBOX<0-2>C2 *
Available Options
Option Argument Description Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 8 bit hex value Set bits 24-31 in config register

IIO general-purpose counters

IIO stacks are responsible for managing traffic between the PCIe domain and the Mesh domain. The IIO PMON block is situated near the IIO stack’s traffic controller capturing traffic controller as well as PCIe root port information. The traffic controller is responsible for translating traffic coming in from the Mesh (through M2PCIe) and processed by IRP into the PCIe domain to IO agents such as CBDMA, PCIe and MCP. The IBOX hardware performance counters are exposed to the operating system through MSR registers.
  • IBOX0*,IBAND0* and IUTIL0* is part of the CBDMA Stack
  • IBOX<1-3>*, IBAND<1-3>* and IUTIL<1-3>* is part of PCIe stack 0-2
  • IIO4 is part of the MCP stack 0
Counters
Counter name Event name
IBOX<0-4>C0 *
IBOX<0-4>C1 *
IBOX<0-4>C2 *
IBOX<0-4>C3 *
Available Options
Option Argument Description Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 12 bit hex value Set bits 24-35 in config register
mask0 8 bit hex mask Channel mask filter, sets bits 36-43 in config register Check Intel® Xeon® Processor Scalable Family Uncore Reference Manual for bit fields.
mask1 3 bit hex address FC mask, sets bits 44-46 in config register Check Intel® Xeon® Processor Scalable Family Uncore Reference Manual for bit fields.

IIO fixed-purpose counters

IIO stacks are responsible for managing traffic between the PCIe domain and the Mesh domain. The IIO PMON block is situated near the IIO stack’s traffic controller capturing traffic controller as well as PCIe root port information. The traffic controller is responsible for translating traffic coming in from the Mesh (through M2PCIe) and processed by IRP into the PCIe domain to IO agents such as CBDMA, PCIe and MCP. The IBOX hardware performance counters are exposed to the operating system through MSR registers.
  • IBOX0*,IBAND0* and IUTIL0* is part of the CBDMA Stack
  • IBOX<1-3>*, IBAND<1-3>* and IUTIL<1-3>* is part of PCIe stack 0-2
  • IBOX4 is part of the MCP stack 0
Counters
Counter name Event name
IBOX<0-4>CLK IUNIT_CLOCKTICKS
IBAND<0-4>PI0 BANDWIDTH_PORT0_IN
IBAND<0-4>PI1 BANDWIDTH_PORT1_IN
IBAND<0-4>PI2 BANDWIDTH_PORT2_IN
IBAND<0-4>PI3 BANDWIDTH_PORT3_IN
IBAND<0-4>PO0 BANDWIDTH_PORT0_OUT
IBAND<0-4>PO1 BANDWIDTH_PORT1_OUT
IBAND<0-4>PO2 BANDWIDTH_PORT2_OUT
IBAND<0-4>PO3 BANDWIDTH_PORT3_OUT
IUTIL<0-4>PI0 UTLILIZATION_PORT0_IN
IUTIL<0-4>PI1 UTLILIZATION_PORT1_IN
IUTIL<0-4>PI2 UTLILIZATION_PORT2_IN
IUTIL<0-4>PI3 UTLILIZATION_PORT3_IN
IUTIL<0-4>PO0 UTLILIZATION_PORT0_OUT
IUTIL<0-4>P1 UTLILIZATION_PORT1_OUT
IUTIL<0-4>P2 UTLILIZATION_PORT2_OUT
IUTIL<0-4>P3 UTLILIZATION_PORT3_OUT

IRP general-purpose counters

IRP is responsible for maintaining coherency for IIO traffic targeting coherent memory. The IBOX hardware performance counters are exposed to the operating system through MSR registers. Each device provides two counters
  • IRP0* is part of the CBDMA Stack
  • IRP<1-3>* is part of PCIe stack 0-2
  • IRP<4-5> is part of the MCP stack 0-1
Counters
Counter name Event name
IRP<0-5>C0 *
IRP<0-5>C1 *
Available Options
Option Argument Description Comment
edgedetect N Set bit 18 in config register
invert N Set bit 23 in config register
threshold 8 bit hex value Set bits 24-31 in config register
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