On 09/08/2010 09:24 AM, Larry Hall (Cygwin) wrote:
To somewhat sooth your curiousity, Windows (or perhaps it's more accurate to say NTFS) ain't great with directories with a large number of files. I expect you would be less than impressed with the performance of of 'dir' in 'cmd.exe' in the same directory. That said, you're asking for allot more work than you may realize when doing the same thing in Cygwin. In order to fill in the information you ask for when you use the '-l' flag for 'ls', Cygwin needs to open and close the files, which takes a good chunk of time en masse. The same does not need to happen in Linux/UNIX-land.
Additionally, the stat() interface is puny - it MUST take the time to fill out the complete struct, even if the caller only cares for part of the information. If the Linux kernel ever incorporates the pending xstat() kernel call[1], then cygwin adds support for it, and coreutils is taught to make good use of it, then operations like ls can be sped up by asking for only the portions of the stat data that they plan on actually using, letting cygwin skip the work of obtaining the rest of the stat information just to be thrown away by the caller.
[1]version 6 of that kernel patch is still being debated; as recently as http://lkml.indiana.edu/hypermail/linux/kernel/1008.2/00274.html
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