Using SPM

Using SPM#

SPM (Streaming Performance Monitor) sampling service for GPU profiling is a profiling technique to periodically sample performance counters with GPU timestamp.

Here are the benefits of using SPM to sample counters:

  • Identify performance bottlenecks

  • Understand kernel execution behavior

  • fine-grained, time-resolved performance data.

To try out the SPM, you can use the command-line tool rocprofv3 or the ROCprofiler-SDK library.

SPM availability and configuration#

To check counters that can be sampled, use:

rocprofv3 -L

Or

rocprofv3 --list-avail

The output lists if rocprofv3 supports SPM

Counter_Name        :   TCC_MISS
Description         :   Number of cache misses. UC reads count as misses.
Block               :   TCC
SPM                 :   Supported
Dimensions          :   DIMENSION_INSTANCE[0:15] DIMENSION_XCC[0:7]

The preceding output shows that the TCC_MISS counter can be sampled.

Note

For proper functioning, SPM requires AMD GPU Driver version 6.19.14.31400000 or later. Before using SPM, verify the loaded amdgpu kernel module version.

To check the driver version, use:

cat /sys/module/amdgpu/version

# Example output:
# 6.19.14.31400000

You can also check this driver version using amd-smi version command on DKMS-built systems.

Use the following command to use SPM:

rocprofv3 --spm-beta-enabled --spm SQ_WAVES --spm-sample-interval-unit sclk_cycles --spm-sample-interval 1200  --output-format json -- <application_path>

The preceding command enables SPM for SQ_WAVES and sample interval with unit as sclk cycle counts. Replace <application_path> with the path to the application you want to profile. This generates a JSON results file prefixed with the process ID.

rocprofv3 --spm-beta-enabled --spm SQ_WAVES --spm-sample-interval-unit sclk_cycles --spm-sample-interval 1200  -- <application_path>

The preceding command enables SPM for SQ_WAVES and sample interval with unit as sclk cycle counts. Replace <application_path> with the path to the application you want to profile. This generates a rocpd results file prefixed with the process ID.

SPM is emitted directly only to the JSON and rocpd (default) output formats. Only CSV output is supported from the rocpd database via rocpd convert.

Input parameters#

Here are the input parameters used to configure SPM

  • Metrics List: The list of counters that you want to sample with SPM. Currently, basic counters are supported.

  • SPM Sample Interval: Specifies the sampling interval for SPM counter collection. It is used with spm-sample-interval-unit to define how frequently counters are sampled.

  • SPM Sample Interval Unit: Specifies the unit for the SPM sample interval. Used with –spm-sample-interval to define the sampling interval. Currently, sclk_cycles unit is supported and the sample interval used with this unit is rounded to nearest multiple of 32.

rocprofv3 --spm-beta-enabled --spm SQ_WAVES --spm-sample-interval-unit sclk_cycles --spm-sample-interval 1200  --output-format json -- <application_path>
rocprofv3 --spm-beta-enabled --spm SQ_WAVES --spm-sample-interval-unit sclk_cycles --spm-sample-interval 1200 -- <application_path>

CSV format conversion#

rocpd convert -i <input-file>.db --output-format csv

The CSV conversion process generates a output file rocpd-output-data/out_spm_counter_collection_trace.csv path relative to the current working directory.

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