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From: Max Motovilov (max_at_[hidden])
Date: 2004-03-02 14:32:38

I forgot to mention that benchmarking code randomly changed the order of
tests to minimize the disparity in cache hit/miss ratios. Also, big
difference in writing/creation times between memory-mapped and file-based
I/O may mean that memory-mappings implement cached writes whereas file
writes are somehow write-through, though it doesn't seem to be the case
according to documentation. Perhaps CloseHandle() waits until all dirty
cache pages are written to the device but does not wait for the dirty pages
that belonged to the memory mapping. It is also possible that file-based
writes and memory-mapped writes are logged differently in the NTFS journal.
None of this should apply to reads, though.


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