TaskRunner: disable implicit threading when using multiprocessing #12
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
We have had trouble with low-level threaded packages (OpenBLAS, MKL) implicitly using multiple threads if the user doesn't explicitly state the number of desired threads, which increases contention when parallelising at a higher level. We disable implicit threading when using multiprocessing to protect the user. Our check can be disabled by the user setting the environment variable LSST_ALLOW_IMPLICIT_THREADS or by explicitly setting the number of threads using the environment variables checked by the low-level threaded package.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
We have had trouble with low-level threaded packages (OpenBLAS, MKL)
implicitly using multiple threads if the user doesn't explicitly state
the number of desired threads, which increases contention when
parallelising at a higher level. We disable implicit threading when
using multiprocessing to protect the user. Our check can be disabled
by the user setting the environment variable LSST_ALLOW_IMPLICIT_THREADS
or by explicitly setting the number of threads using the environment
variables checked by the low-level threaded package.