Enable parallel memset/memcpy in clear_x_field/copy_x_field.#94
Open
SaltyChiang wants to merge 2 commits intomilc-qcd:developfrom
Open
Enable parallel memset/memcpy in clear_x_field/copy_x_field.#94SaltyChiang wants to merge 2 commits intomilc-qcd:developfrom
clear_x_field/copy_x_field.#94SaltyChiang wants to merge 2 commits intomilc-qcd:developfrom
Conversation
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
clear_x_field/copy_x_fieldfunctions only use a single process to perform the memcpy/memset, which cannot utilize the full memory bandwidth on modern CPUs. Also, there are some memset calls to clear memory for gauge fields in the RHMC/RHMD algorithm. They contribute the most of the overall CPU overhead.Parallel memcpy and memset calls are used in
clear_x_fieldandcopy_x_fieldfunctions, and memset calls to clear a gauge field are replaced byclear_m_array_field. Generally, it will reduce more than half of the CPU overhead.Also,
scalar_mult_fn+add_fncan be fused into one callscalar_mult_add_fn, which is obviously better since it will only read and write the field 3 times instead of 5 times.