Find-Db Database

Prior to MIOpen 2.0, users utilized 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. In MIOpen 2.0 an immediate mode is introduced.

Immediate mode is based on a database which contains the results of calls to the legacy Find() stage. This database is called Find-Db. It consists of two parts:

  • System Find-Db, a system-wide storage which holds the pre-run values for the most applicable configurations,
  • User Find-Db, a per-user storage which is intended to hold results for arbitrary user-run configurations. It also performs double duty as a cache for the Find() stage.

The User Find-Db always takes precedence over System Find-Db.

By default, System Find-Db resides within MIOpen’s install location, while User Find-Db resides in the user’s home directory. See Setting up locations for more information.

  • The System Find-Db is not modified upon installation of MIOpen.
  • There are separate Find databases for HIP and OpenCL backends.

Populating the User Find-Db

MIOpen collects Find-db information during the following MIOpen API calls:

  • miopenFindConvolutionForwardAlgorithm()
  • miopenFindConvolutionBackwardDataAlgorithm()
  • miopenFindConvolutionBackwardWeightsAlgorithm()

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

Updating MIOpen and the User Find-Db

When the user installs a new version of MIOpen, the new version of MIOpen will ignore old User find-db* files. Thus, the user is not required to move or delete their old User find-db files. However, the user may wish to re-collect the information into their brand new User find-db. This should be done in the same way as it was done with the previous version of the library – if it was done. This would keep Immediate mode optimized.

Disabling Find-Db

By default MIOpen will use the Find-Db. Users can disable the Find-Db by setting the environmental variable MIOPEN_DEBUG_DISABLE_FIND_DB to 1:

export MIOPEN_DEBUG_DISABLE_FIND_DB=1

Note: The System Find-Db has the ability to be cached into memory and may increase performance dramatically. To disable this option use the cmake configuration flag:

-DMIOPEN_DEBUG_FIND_DB_CACHING=Off