Bug 337797

I use ZFS (http://zfsonlinux.org/faq.html) - all my /, /usr, /home /var and so on are on the same disk partition, but as different ZFS 'filesystems'.

I use ZFS snapshots as a first line backup system. Because snapshots work on a 'filesystem' basis, and because ZFS 'filesystems' are much lighter-weight than the equivalent with e.g. ext4 where you have to allocate space specifically for that FS, I have lots of 'filesystems' for e.g /home/me/Documents, /home/me/Videos etc, because I want to have different backup policies for music vs normal documents. Including things like /proc, /tmp etc, I have 89 mountpoints as opposed to the 12 or so that a normal system would have.

Whenever I plug in, mount, unmount or remove a USB stick, and whenever a new ZFS snapshot is created, my system becomes slow or even unresponsive for a few tens of seconds. Looking at `top`, it is apparent that every `dolphin` process is using 100% CPU (or as much as it can, when there are more `dolphin` processes than cores). `udisksd` is also using 100% CPU.

Could it be possible to do either/both of:
1) Cache the results of whatever calculation is happening so that only the newly added / removed partition needs to be probed?
2) Do the calculation once and share the results rather than repeating in every Dolphin process on the system?