pfelf: separate mmap reader from the underlying reader#1395
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This prepares pfelf for the upcoming removal of mmap suppport. To start with, the 'elfReader' is always the underlying original reader it was handed. The mmap is now attempted at open time if possible, and used if it succeeded. This will start reducing the RSS once the Prog/Section.Data() is no longer used. PR open-telemetry#1393 adds a new Underlying() method to access the data without the mmap together with few users. This PR should remove the temporary RSS spikes during scanning the large segments in that PR.
christos68k
approved these changes
May 4, 2026
| // Close closes the File. | ||
| func (f *File) Close() (err error) { | ||
| if f.mmapReader != nil { | ||
| f.mmapReader.Close() |
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Shouldn't we set f.mmapReader to nil here? Maybe also combine all errors into one.
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mmapReader.Close() cannot return an actual error. I can add the explicit discard and comment. This will eventually go away when the removal of mmap is complete.
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| if osFile, ok := r.(*os.File); ok { | ||
| // Attempt to mmap the file if possible | ||
| f.mmapReader, _ = mmap.OpenFile(osFile) |
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Maybe add a log.Debugf here, wrapping the error with the filename (osFile.Name()) since we removed the filename from the source error
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This will eventually go away. The code is also able to handle things without mmap. So I'm not sure if its worth even a debug note.
Co-authored-by: Christos Kalkanis <christos.kalkanis@elastic.co>
florianl
approved these changes
May 11, 2026
This was referenced May 15, 2026
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This prepares pfelf for the upcoming removal of mmap suppport. To start with, the 'elfReader' is always the underlying original reader it was handed. The mmap is now attempted at open time if possible, and used if it succeeded.
This will start reducing the RSS once the Prog/Section.Data() is no longer used. PR #1393 adds a new Underlying() method to access the data without the mmap together with few users. This PR should remove the temporary RSS spikes during scanning the large segments in that PR.