Remove unnecessary DMA constraint #17
Open
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
This change removes the DMA constraint that requires buffer sizes to be a multiple of 512. This has a side effect of causing bounce buffers to be used when a buffer address is not a multiple of 512. Runtime testing shows that vSAN IOs are often only 8-byte aligned, and the end result is a significant reduction of performance compared to when this constraint isn't specified.
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Outdated suggestions cannot be applied.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.
This change removes the DMA constraint that requires buffer sizes to be a multiple of 512. This has a side effect of causing bounce buffers to be used when a buffer address is not a multiple of 512. Runtime testing shows that vSAN IOs are often only 8-byte aligned, and the end result is a significant reduction of performance compared to when this constraint isn't specified.