sync() slowdown

Hi git users,

I use git (a very basic usage) every day and I noticed a big slowdown
when I do a "git repack -a -d".

I noticed that it only happens when I do backup to an usb stick.

After a few investigation, I noticed that sync() is call when repacking
objects (from both builtin-prune.c and builtin-prune-packed.c).

I do understand that syncing filesystem is usefull and needed.

But is there a good idea to add a --no-sync option to prevent that
behaviour ?

I think this might be useful if you repack many repositories.
If you call the sync command before looping the repacks I guess this
could be equivalent (modulo changes done in repositories during that
time).

Any idea suggestions ?


Thanks lot

Cheers.

-- 
Sébastien Gross