git performance after directory copy

Hello all,

while moving a project directory around I stumbled over an interesting phenomenon. On a copied source directory "git status" seems to be about 3 times slower than on the original directory. Only after a "git reset" both copies behave the same again. Is this connected to the timestamps of files & directories? Actually I would like to move the project directories of several software developers to a new partition and forcing them all to "git reset" in all of their repos is a little bit annoying. Any suggestions how to "repair" the repos less intrusive?

Here's how I measured. The trees reside on an ext3 FS. I have lots of free RAM, so after the first operation all further "git status" seem to run from FS cache in RAM.

$ git clone <path to your preferred kernel> $ cd kernel $ time git status # several times! ... $ time git status # On branch master nothing to commit (working directory clean)

real 0m0.691s user 0m0.256s sys 0m0.356s

$ cd .. $ rsync -a kernel/ kernel2/ $ cd kernel2 $ time git status # several times! ... $ time git status # On branch master nothing to commit (working directory clean)

real 0m2.705s user 0m1.724s sys 0m0.816s

$ git reset $ time git status # On branch master nothing to commit (working directory clean)

real 0m0.704s user 0m0.296s sys 0m0.348s

Regards,
 Andreas.