10 jul 2012 kl. 22.38 skrev Peter Samuelson:
Whatever it is in the data path that makes it slower, it probably is
not a fair comparison. Even though we normally don't want to do our
own fdatasync(), it is fair to consider the additional I/O load that
is
generated by Subversion operations. That the I/O might happen in the
background after an svn operation finishes does not make it "free"
from
the user's standpoint.
I re-ran the checkout test followed by an immediate sync in a simple
attempt to test your hypothesis, but the difference remained:
standard exclusive locking
btrfs 33.1 26.0
btrfs + COW 36.4 27.2
Even so, I still believe using COW where available would be a sensible
move, for the disk space savings if nothing else.
