Chris Murphy <lists(a)colorremedies.com> writes:
On Apr 27, 2012, at 9:53 AM, Jeff Moyer wrote:
> 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:
>>
>> kworker/1:2
>> kworker/0:4
>>
>> 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
>> HFS+.
>>
>> Odd?
>
> Sounds like lazy itable init. Try mkfs -t ext4 -E lazy_itable_init=0.
This is happening on internal disks, targeted for Fedora
installation. I can hear it once install is complete, still booted
from DVD media. Is this a bug?
So long as the file system is mounted and the itable initialization is
not complete, I would expect the initialization to continue. Does that
answer your question?
Cheers,
Jeff