Chris Murphy <lists(a)colorremedies.com> writes:
Normally top reports CPU line, sy at 0.4% when idle. If I format an
external Firewire disk as btrfs and mount it, it remains at 0.4%. If I
reformat as XFS and mount it, again top reports sy at 0.4%. However,
if I reformat as ext4 and mount it, sy runs at 3.5%. These two
processes are now at the top of top's results:
Each uses on average 1.9% CPU. The light on the external drive flashes
4x per second. There are no processes using the disk at all while this
is going on. If I umount it, the pulsing stops. If I remount it, the
pulsing resumes as does the slightly higher CPU consumption.
This doesn't happen with the same hardware mounted XFS or btrfs or
Sounds like lazy itable init. Try mkfs -t ext4 -E lazy_itable_init=0.