Force alignment of opal_atomic_int128_t to be 16B #13281
Merged
+1
−1
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
Some architectures will align 128bit integer on 8B but require 16B alignment for 128bit CAS instructions and otherwise fall back to a lock-based atomicity model. By forcing 16bit alignment we can ensure that the variables are properly aligned and the fall-back is not triggered. Thanks to Ulrich Weigand for the analysis and proposed fix in open-mpi#10988 (comment). Signed-off-by: Joseph Schuchart <[email protected]>
bosilca
approved these changes
May 28, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.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.
Some architectures will align 128bit integer on 8B but require 16B alignment for 128bit CAS instructions and otherwise fall back to a lock-based atomicity model. By forcing 16bit alignment we can ensure that the variables are properly aligned and the fall-back is not triggered.
Thanks to Ulrich Weigand for the analysis and proposed fix in #10988 (comment).
Fixes #10988.