rygorous/gist:5230065

## gistfile1.txt
From: Casey Muratori, 10/17/12

Well, you will notice that that loop _does not_ stat unless it's
running on a filesystem that doesn't support readdir dtypes (because
it needs to know whether or not to recurse, which you can do with the
dtype on ext*, but not on NTFS et al, since they didn't bother to
implement it or something - everything comes back as DT_UNKNOWN).  I
haven't looked at the code to find out if/where they actually do stat
as a matter of course elsewhere, but as I mentioned last night, it is
_only the stat_ that causes the catastrophic case.  In my experiments,
readdir without stat is always extremely fast, cached or otherwise.
	From: Casey Muratori, 10/17/12

	Well, you will notice that that loop _does not_ stat unless it's
	running on a filesystem that doesn't support readdir dtypes (because
	it needs to know whether or not to recurse, which you can do with the
	dtype on ext*, but not on NTFS et al, since they didn't bother to
	implement it or something - everything comes back as DT_UNKNOWN). I
	haven't looked at the code to find out if/where they actually do stat
	as a matter of course elsewhere, but as I mentioned last night, it is
	_only the stat_ that causes the catastrophic case. In my experiments,
	readdir without stat is always extremely fast, cached or otherwise.