Parallel algorithms POC #559
Draft
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
breznak
added
in_progress
optimization
code
try execution::par_unseq for inhibition in SP. Results: takes much longer than seq.
This reverts commit b27b40c.
breznak
commented
Jul 17, 2019
There was a problem hiding this comment.
Please review if there's an obvious error or if the MNIST_SP.cpp settings may be too artificial.
Otherwise my parallelization effort using c++17 TS Parallel has hit the reality.
- The problem is memory bound
execution::par_unseqreally puts all threads to a good use- MNIST is still slower than single-thread!
- significantly: 60s (single) vs 240+s (parallel)
- likely broken cache locality
- or even CPU throttling (or boosting the only signle thread running)
| @@ -844,19 +845,25 @@ void SpatialPooler::inhibitColumnsGlobal_(const vector<Real> &overlaps, | |||
| // faster than a regular sort because it stops after it partitions the | |||
| // elements about the Nth element, with all elements on their correct side of | |||
| // the Nth element. | |||
| std::nth_element( | |||
| tNth.start(); | |||
| std::nth_element(htm::parallel::mode, | |||
There was a problem hiding this comment.
inhibition identified as one of the slowest methods in SP.
nth_element as the most significant in global inh.
3 tasks
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Outdated suggestions cannot be applied.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.
parallel TSFor #214 #254
This is for your interest, not intended for merging yet.