I recall the consensus was that a /proc tunable was "too much" for the initial patch. An atime update interval of 1 day is sufficient for most applications, since they run daily to do file access scanning. The #define was added because I dislike having multiple hard-coded values in any code.
I haven't heard of any complaints about the relatime update frequency, except for this "atime in the future" problem, so until that happens we may as well leave it as-is.
Cheers, Andreas
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