Details
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Improvement
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Resolution: Unresolved
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Minor
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None
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9223372036854775807
Description
We have seen some customer workloads doing mmap where the mmap readahead algorithm works very poorly. Investigation showed that the workload is much more like a traditional sequential workload. Changing the mmap readahead tunables and using madvise both did not result in good readahead behavior.
Instead, we tried allowing mmap readahead to use the standard readahead logic, rather than the mmap specific logic. This worked really well for this workload, so I'm pushing a patch to make that a tunable.