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.

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.

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>
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