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Re: Do we really need correct st_nlink count for directories?


According to Eric Blake on 4/24/2008 7:32 AM:
But if it takes an entire directory read to determine a correct st_nlink, in order to avoid an entire directory as an optimization, then it isn't optimal. I'm all for dropping correct st_nlink, and using 1 instead.

More importantly, if it will speed up the stat() of a directory in the case where the st_nlink optimization is not being used (which I believe is more often the case), then the performance improvement of not counting subdirs for a faster stat() definitely outweighs the loss in optimization on the few places where the readdir() st_nlink optimization even makes sense (for example, even though find is coded to use the st_nlink optimization, I would hazard a guess that less than 50% of find queries are actually able to use it, because there are only a limited subset of queries where you only care about identifying subdirectories, rather than visiting all files in the directory).


--
Don't work too hard, make some time for fun as well!

Eric Blake ebb9@byu.net


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