Using the find database

Using the find database#

Prior to MIOpen 2.0, you could use calls (such as miopenFindConvolution*Algorithm()) to gather a set of convolution algorithms in the form of an array of miopenConvSolution_t structs. This process is time-consuming because it requires online benchmarking of competing algorithms.

As of MIOpen 2.0, we introduced an immediate mode, which is based on a database that contains the results of calls to the legacy Find() stage. We refer to the find database as FindDb.

FindDb consists of two parts:

  • System FindDb: A system-wide storage that holds pre-run values for the most applicable configurations.

  • User FindDb: A per-user storage that holds results for arbitrary user-run configurations. It also serves as a cache for the Find() stage.

User FindDb always takes precedence over System FindDb.

By default, System FindDb resides within MIOpen’s install location, while User FindDb resides in your home directory.

Note that:

  • The System FindDb is not modified upon installation of MIOpen.

  • There are separate Find databases for HIP and OpenCL backends.

Populating User FindDb#

MIOpen collects FindDb information during the following API calls:

  • miopenFindConvolutionForwardAlgorithm()

  • miopenFindConvolutionBackwardDataAlgorithm()

  • miopenFindConvolutionBackwardWeightsAlgorithm()

During the call, find data entries are collected for one problem configuration, which is implicitly defined by the tensor descriptors and convolution descriptor passed to API function.

Updating MIOpen and User FindDb#

When you install a new version of MIOpen, this new version ignores old User FindDb files. Therefore, you don’t need to move or delete the old User FindDb files.

If you want to re-collect the information into the new User FindDb, you can use the same steps you followed in the previous version. Re-collecting information keeps immediate mode optimized.

Disabling FindDb#

You can disable FindDb by setting the MIOPEN_DEBUG_DISABLE_FIND_DB environmental variable to 1:

export MIOPEN_DEBUG_DISABLE_FIND_DB=1

Note

System FindDb can be cached into memory and may dramatically increase performance. To disable this option, set the DMIOPEN_DEBUG_FIND_DB_CACHING CMake configuration flag to off.

-DMIOPEN_DEBUG_FIND_DB_CACHING=Off
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