[systemd-devel] systemd-udevd: excessive I/O usage

[Kok, Auke-jan H]

On Mon, Jun 4, 2012 at 3:19 PM, Peeters Simon <peeters.simon at gmail.com> wrote:
> 2012/6/4 Kok, Auke-jan H <auke-jan.h.kok at intel.com>:
>> On Mon, Jun 4, 2012 at 1:48 PM, Peeters Simon <peeters.simon at gmail.com> wrote:
>>
>> Could you recreate the bootchart, but this time, boot with
>> "initcall_debug=1" on the kernel commandline as well?
>>
>> This may provide some hints why your system is taking very long to
>> start doing readahead.
>
> seems like there is something about this readahead, without it bootup
> seems to be faster.
> i attached another bootchart without readahead (featuring gdm at the 10s marker)

we already know that systemd's readahead is having a hard time tuning
read_ahead_kb for spinning disks on btrfs, and is probably not doing
the right thing. It's one of the things I need to follow up on and
definitely needs fixing.

yes, you may be better off without it, although the difference will be minute.

Auke