gh-120754: Update estimated_size in C truncate#121357
Merged
vstinner merged 1 commit intopython:mainfrom Jul 4, 2024
Merged
Conversation
Sometimes a large file is truncated (test_largefile). While estimated_size is used as a estimate (the read will stil get the number of bytes in the file), that it is much larger than the actual size of data can result in a significant over allocation and sometimes lead to a MemoryError / running out of memory. This brings the C implementation to match the Python _pyio implementation.
Contributor
Author
|
Validated memory usage decrease by running under https://www.gnu.org/software/time/
|
noahbkim
pushed a commit
to hudson-trading/cpython
that referenced
this pull request
Jul 11, 2024
Sometimes a large file is truncated (test_largefile). While estimated_size is used as a estimate (the read will stil get the number of bytes in the file), that it is much larger than the actual size of data can result in a significant over allocation and sometimes lead to a MemoryError / running out of memory. This brings the C implementation to match the Python _pyio implementation.
estyxx
pushed a commit
to estyxx/cpython
that referenced
this pull request
Jul 17, 2024
Sometimes a large file is truncated (test_largefile). While estimated_size is used as a estimate (the read will stil get the number of bytes in the file), that it is much larger than the actual size of data can result in a significant over allocation and sometimes lead to a MemoryError / running out of memory. This brings the C implementation to match the Python _pyio implementation.
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
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
goal: Fix buildbot failure https://github.com/python/cpython/pull/120755
Sometimes a large file is truncated (test_largefile). While estimated_size is used as a estimate (the read will get all the bytes in the file when it is wrong), that it is much larger than the actual size of data can result in a significant over allocation and sometimes lead to a MemoryError / running out of memory.
This brings the C implementation to match the Python _pyio implementation.
cc: @vstinner
I've been unable to reproduce the failure locally so far by running
./build/python -bb -E -Wd -m test -r -w -uall test_largefile. My suspicion is that the AMD64 box has limited memory. Working to try and test peak memory usage in the test / if that went down