- /* Initialize only once, by sleeping for 1 millisecond. If that
- was enough to observe a difference, then we are set;
- otherwise fall back to 2 seconds. */
+ /* Initialize only once, by sleeping for 20 milliseconds (needed
+ since xfs has a quantization of about 10 milliseconds, even
+ though it has a granularity of 1 nanosecond, and since NTFS
+ has a default quantization of 15.25 milliseconds, even though
+ it has a granularity of 100 nanoseconds). If the seconds
+ differ, repeat the test one more time (in case we crossed a
+ quantization boundary on a file system with 1 second
+ resolution). If we can't observe a difference in only the
+ nanoseconds, then fall back to 1 second if the time is odd,
+ and 2 seconds (needed for FAT) if time is even. */