[systemd-devel] Improve boot-time of systemd

[Lennart Poettering]

On Wed, 30.03.11 02:28, fykcee1 at gmail.com (fykcee1 at gmail.com) wrote:

> 
> 2011/3/29 Lennart Poettering <lennart at poettering.net>:
> > On Tue, 29.03.11 03:36, fykcee1 at gmail.com (fykcee1 at gmail.com) wrote:
> >> To make boot fast, it seems udev's coldplug do too much jobs -- what I
> >> expect is only coldplug local block devices and tty in that stage.
> >> This can save ~2s in my boot test.
> >>
> >> Is it possible to support .device unit files?
> >
> > Hmm?
> >
> > Note sure I understand the question, but for a .device unit to show up
> > in systemd it must be tagged "systemd" in udev, which only can happen
> > when the device was triggered after udev is started.
> 
> I've already known that currently systemd can only add .device units
> from udev. My question was "Is it suitable for systemd to add supports
> of loading .device units from .device unit files in
> /lib/systemd/system ?"

systemd reads .device units just fine from disk. In fact you don't have
to do any kind of configuration for them.

If you do "systemctl start foobar.device" this call will wait for a
device of that name to show up. You can make up any name you want with
this. If such a device never shows up then it might eventually time out
though.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.