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diff --git a/Documentation/admin-guide/perf/nvidia-pmu.rst b/Documentation/admin-guide/perf/nvidia-pmu.rst new file mode 100644 index 000000000000..2e0d47cfe7ea --- /dev/null +++ b/Documentation/admin-guide/perf/nvidia-pmu.rst @@ -0,0 +1,299 @@ +========================================================= +NVIDIA Tegra SoC Uncore Performance Monitoring Unit (PMU) +========================================================= + +The NVIDIA Tegra SoC includes various system PMUs to measure key performance +metrics like memory bandwidth, latency, and utilization: + +* Scalable Coherency Fabric (SCF) +* NVLink-C2C0 +* NVLink-C2C1 +* CNVLink +* PCIE + +PMU Driver +---------- + +The PMUs in this document are based on ARM CoreSight PMU Architecture as +described in document: ARM IHI 0091. Since this is a standard architecture, the +PMUs are managed by a common driver "arm-cs-arch-pmu". This driver describes +the available events and configuration of each PMU in sysfs. Please see the +sections below to get the sysfs path of each PMU. Like other uncore PMU drivers, +the driver provides "cpumask" sysfs attribute to show the CPU id used to handle +the PMU event. There is also "associated_cpus" sysfs attribute, which contains a +list of CPUs associated with the PMU instance. + +.. _SCF_PMU_Section: + +SCF PMU +------- + +The SCF PMU monitors system level cache events, CPU traffic, and +strongly-ordered (SO) PCIE write traffic to local/remote memory. Please see +:ref:`NVIDIA_Uncore_PMU_Traffic_Coverage_Section` for more info about the PMU +traffic coverage. + +The events and configuration options of this PMU device are described in sysfs, +see /sys/bus/event_sources/devices/nvidia_scf_pmu_<socket-id>. + +Example usage: + +* Count event id 0x0 in socket 0:: + + perf stat -a -e nvidia_scf_pmu_0/event=0x0/ + +* Count event id 0x0 in socket 1:: + + perf stat -a -e nvidia_scf_pmu_1/event=0x0/ + +NVLink-C2C0 PMU +-------------------- + +The NVLink-C2C0 PMU monitors incoming traffic from a GPU/CPU connected with +NVLink-C2C (Chip-2-Chip) interconnect. The type of traffic captured by this PMU +varies dependent on the chip configuration: + +* NVIDIA Grace Hopper Superchip: Hopper GPU is connected with Grace SoC. + + In this config, the PMU captures GPU ATS translated or EGM traffic from the GPU. + +* NVIDIA Grace CPU Superchip: two Grace CPU SoCs are connected. + + In this config, the PMU captures read and relaxed ordered (RO) writes from + PCIE device of the remote SoC. + +Please see :ref:`NVIDIA_Uncore_PMU_Traffic_Coverage_Section` for more info about +the PMU traffic coverage. + +The events and configuration options of this PMU device are described in sysfs, +see /sys/bus/event_sources/devices/nvidia_nvlink_c2c0_pmu_<socket-id>. + +Example usage: + +* Count event id 0x0 from the GPU/CPU connected with socket 0:: + + perf stat -a -e nvidia_nvlink_c2c0_pmu_0/event=0x0/ + +* Count event id 0x0 from the GPU/CPU connected with socket 1:: + + perf stat -a -e nvidia_nvlink_c2c0_pmu_1/event=0x0/ + +* Count event id 0x0 from the GPU/CPU connected with socket 2:: + + perf stat -a -e nvidia_nvlink_c2c0_pmu_2/event=0x0/ + +* Count event id 0x0 from the GPU/CPU connected with socket 3:: + + perf stat -a -e nvidia_nvlink_c2c0_pmu_3/event=0x0/ + +NVLink-C2C1 PMU +------------------- + +The NVLink-C2C1 PMU monitors incoming traffic from a GPU connected with +NVLink-C2C (Chip-2-Chip) interconnect. This PMU captures untranslated GPU +traffic, in contrast with NvLink-C2C0 PMU that captures ATS translated traffic. +Please see :ref:`NVIDIA_Uncore_PMU_Traffic_Coverage_Section` for more info about +the PMU traffic coverage. + +The events and configuration options of this PMU device are described in sysfs, +see /sys/bus/event_sources/devices/nvidia_nvlink_c2c1_pmu_<socket-id>. + +Example usage: + +* Count event id 0x0 from the GPU connected with socket 0:: + + perf stat -a -e nvidia_nvlink_c2c1_pmu_0/event=0x0/ + +* Count event id 0x0 from the GPU connected with socket 1:: + + perf stat -a -e nvidia_nvlink_c2c1_pmu_1/event=0x0/ + +* Count event id 0x0 from the GPU connected with socket 2:: + + perf stat -a -e nvidia_nvlink_c2c1_pmu_2/event=0x0/ + +* Count event id 0x0 from the GPU connected with socket 3:: + + perf stat -a -e nvidia_nvlink_c2c1_pmu_3/event=0x0/ + +CNVLink PMU +--------------- + +The CNVLink PMU monitors traffic from GPU and PCIE device on remote sockets +to local memory. For PCIE traffic, this PMU captures read and relaxed ordered +(RO) write traffic. Please see :ref:`NVIDIA_Uncore_PMU_Traffic_Coverage_Section` +for more info about the PMU traffic coverage. + +The events and configuration options of this PMU device are described in sysfs, +see /sys/bus/event_sources/devices/nvidia_cnvlink_pmu_<socket-id>. + +Each SoC socket can be connected to one or more sockets via CNVLink. The user can +use "rem_socket" bitmap parameter to select the remote socket(s) to monitor. +Each bit represents the socket number, e.g. "rem_socket=0xE" corresponds to +socket 1 to 3. +/sys/bus/event_sources/devices/nvidia_cnvlink_pmu_<socket-id>/format/rem_socket +shows the valid bits that can be set in the "rem_socket" parameter. + +The PMU can not distinguish the remote traffic initiator, therefore it does not +provide filter to select the traffic source to monitor. It reports combined +traffic from remote GPU and PCIE devices. + +Example usage: + +* Count event id 0x0 for the traffic from remote socket 1, 2, and 3 to socket 0:: + + perf stat -a -e nvidia_cnvlink_pmu_0/event=0x0,rem_socket=0xE/ + +* Count event id 0x0 for the traffic from remote socket 0, 2, and 3 to socket 1:: + + perf stat -a -e nvidia_cnvlink_pmu_1/event=0x0,rem_socket=0xD/ + +* Count event id 0x0 for the traffic from remote socket 0, 1, and 3 to socket 2:: + + perf stat -a -e nvidia_cnvlink_pmu_2/event=0x0,rem_socket=0xB/ + +* Count event id 0x0 for the traffic from remote socket 0, 1, and 2 to socket 3:: + + perf stat -a -e nvidia_cnvlink_pmu_3/event=0x0,rem_socket=0x7/ + + +PCIE PMU +------------ + +The PCIE PMU monitors all read/write traffic from PCIE root ports to +local/remote memory. Please see :ref:`NVIDIA_Uncore_PMU_Traffic_Coverage_Section` +for more info about the PMU traffic coverage. + +The events and configuration options of this PMU device are described in sysfs, +see /sys/bus/event_sources/devices/nvidia_pcie_pmu_<socket-id>. + +Each SoC socket can support multiple root ports. The user can use +"root_port" bitmap parameter to select the port(s) to monitor, i.e. +"root_port=0xF" corresponds to root port 0 to 3. +/sys/bus/event_sources/devices/nvidia_pcie_pmu_<socket-id>/format/root_port +shows the valid bits that can be set in the "root_port" parameter. + +Example usage: + +* Count event id 0x0 from root port 0 and 1 of socket 0:: + + perf stat -a -e nvidia_pcie_pmu_0/event=0x0,root_port=0x3/ + +* Count event id 0x0 from root port 0 and 1 of socket 1:: + + perf stat -a -e nvidia_pcie_pmu_1/event=0x0,root_port=0x3/ + +.. _NVIDIA_Uncore_PMU_Traffic_Coverage_Section: + +Traffic Coverage +---------------- + +The PMU traffic coverage may vary dependent on the chip configuration: + +* **NVIDIA Grace Hopper Superchip**: Hopper GPU is connected with Grace SoC. + + Example configuration with two Grace SoCs:: + + ********************************* ********************************* + * SOCKET-A * * SOCKET-B * + * * * * + * :::::::: * * :::::::: * + * : PCIE : * * : PCIE : * + * :::::::: * * :::::::: * + * | * * | * + * | * * | * + * ::::::: ::::::::: * * ::::::::: ::::::: * + * : : : : * * : : : : * + * : GPU :<--NVLink-->: Grace :<---CNVLink--->: Grace :<--NVLink-->: GPU : * + * : : C2C : SoC : * * : SoC : C2C : : * + * ::::::: ::::::::: * * ::::::::: ::::::: * + * | | * * | | * + * | | * * | | * + * &&&&&&&& &&&&&&&& * * &&&&&&&& &&&&&&&& * + * & GMEM & & CMEM & * * & CMEM & & GMEM & * + * &&&&&&&& &&&&&&&& * * &&&&&&&& &&&&&&&& * + * * * * + ********************************* ********************************* + + GMEM = GPU Memory (e.g. HBM) + CMEM = CPU Memory (e.g. LPDDR5X) + + | + | Following table contains traffic coverage of Grace SoC PMU in socket-A: + + :: + + +--------------+-------+-----------+-----------+-----+----------+----------+ + | | Source | + + +-------+-----------+-----------+-----+----------+----------+ + | Destination | |GPU ATS |GPU Not-ATS| | Socket-B | Socket-B | + | |PCI R/W|Translated,|Translated | CPU | CPU/PCIE1| GPU/PCIE2| + | | |EGM | | | | | + +==============+=======+===========+===========+=====+==========+==========+ + | Local | PCIE |NVLink-C2C0|NVLink-C2C1| SCF | SCF PMU | CNVLink | + | SYSRAM/CMEM | PMU |PMU |PMU | PMU | | PMU | + +--------------+-------+-----------+-----------+-----+----------+----------+ + | Local GMEM | PCIE | N/A |NVLink-C2C1| SCF | SCF PMU | CNVLink | + | | PMU | |PMU | PMU | | PMU | + +--------------+-------+-----------+-----------+-----+----------+----------+ + | Remote | PCIE |NVLink-C2C0|NVLink-C2C1| SCF | | | + | SYSRAM/CMEM | PMU |PMU |PMU | PMU | N/A | N/A | + | over CNVLink | | | | | | | + +--------------+-------+-----------+-----------+-----+----------+----------+ + | Remote GMEM | PCIE |NVLink-C2C0|NVLink-C2C1| SCF | | | + | over CNVLink | PMU |PMU |PMU | PMU | N/A | N/A | + +--------------+-------+-----------+-----------+-----+----------+----------+ + + PCIE1 traffic represents strongly ordered (SO) writes. + PCIE2 traffic represents reads and relaxed ordered (RO) writes. + +* **NVIDIA Grace CPU Superchip**: two Grace CPU SoCs are connected. + + Example configuration with two Grace SoCs:: + + ******************* ******************* + * SOCKET-A * * SOCKET-B * + * * * * + * :::::::: * * :::::::: * + * : PCIE : * * : PCIE : * + * :::::::: * * :::::::: * + * | * * | * + * | * * | * + * ::::::::: * * ::::::::: * + * : : * * : : * + * : Grace :<--------NVLink------->: Grace : * + * : SoC : * C2C * : SoC : * + * ::::::::: * * ::::::::: * + * | * * | * + * | * * | * + * &&&&&&&& * * &&&&&&&& * + * & CMEM & * * & CMEM & * + * &&&&&&&& * * &&&&&&&& * + * * * * + ******************* ******************* + + GMEM = GPU Memory (e.g. HBM) + CMEM = CPU Memory (e.g. LPDDR5X) + + | + | Following table contains traffic coverage of Grace SoC PMU in socket-A: + + :: + + +-----------------+-----------+---------+----------+-------------+ + | | Source | + + +-----------+---------+----------+-------------+ + | Destination | | | Socket-B | Socket-B | + | | PCI R/W | CPU | CPU/PCIE1| PCIE2 | + | | | | | | + +=================+===========+=========+==========+=============+ + | Local | PCIE PMU | SCF PMU | SCF PMU | NVLink-C2C0 | + | SYSRAM/CMEM | | | | PMU | + +-----------------+-----------+---------+----------+-------------+ + | Remote | | | | | + | SYSRAM/CMEM | PCIE PMU | SCF PMU | N/A | N/A | + | over NVLink-C2C | | | | | + +-----------------+-----------+---------+----------+-------------+ + + PCIE1 traffic represents strongly ordered (SO) writes. + PCIE2 traffic represents reads and relaxed ordered (RO) writes. |