Pr/v3.1.x floating point division problem #6344
Merged
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 commit fixes a problem reported on the mailing list with individual writes larger than 512 MB. The culprit is a floating point division of two large, close values. Changing the datatypes from float to double (which is what is being used in the fcoll components) fixes the problem. See issue open-mpi#6285 and https://forum.hdfgroup.org/t/cannot-write-more-than-512-mb-in-1d/5118 Thanks for Axel Huebl and René Widera for reporting the issue. Signed-off-by: Edgar Gabriel <[email protected]> (cherry picked from commit c0f8ce0)
Similar to open-mpi#6286 rounding number of bytes into a single precision floating point value to round up the result of a division is a potential risk due to rounding errors. - remove floating point operations for `round up` - removes floating point conversion for round down (native behavior of integer division) Signed-off-by: René Widera <[email protected]> Note: a direct cherry pick of commit a91fab8 is not possible, due to structural differences between the the 3.1.x and the master/v4.0.x branch. This commit is the equivalent of commit a91fab8. Signed-off-by: Edgar Gabriel <[email protected]>
jsquyres
approved these changes
Jan 31, 2019
This was referenced Feb 23, 2019
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 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Outdated suggestions cannot be applied.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.
bring the two commits related to possible rounding problems due to an erroneous typecast to a float over to the 3.1 branch. Note, that one of the two commits could not be directly cherry-picked.