[systemd-devel] Understanding systemd-analyze's plots

Gustavo Sverzut Barbieri barbieri at profusion.mobi
Sat Nov 26 20:06:28 PST 2011


Can't look in details now, but from your mail please check for extra udev
rules that may be slowing down and also remove useless stuff such as
hostname as systemd does it without scripts. Also check your libc and
kernel supports accept4 syscall

On Saturday, November 26, 2011, Stefan Majewsky <
stefan.majewsky at googlemail.com> wrote:
> Hi,
>
> my openSUSE 12.1 system boots in about 30 seconds, and I wanted to cut
> that time down a bit, so I took a look at systemd-analyze's blame and
> plot output.
>
> But I do not really know how to interpret the results which I see in
> the plot [1]. The startup sequence takes 20.5 seconds in userspace, of
> which only the last 3 seconds seem to be spent on what I consider "the
> interesting stuff": starting all sorts of services and finally
> bringing up KDM.
>
> The rest of the time seems to be spent activating the hardware,
> various mounts and udev. (According to the LED on my notebook's case,
> the disk is busy all the time.) To put my confusion into questions:
>
> 1. Why does the system need 6 seconds (from t=6.3s to t=12.3s on the
> plot) to activate some tmpfs mounts?
>
> 2. Why is localnet.service activating for a whole 7 seconds? I looked
> into it, it's only a SysV init script that sets hostname and
> domainname from the config in /etc, yet it's number 1 in
> systemd-analyze blame.
>
> 3. Why does it look like about nothing happens between t=13s and t=22s?
>
> It might be that openSUSE's unit files (or SysV leftovers) are not yet
> optimized for the early boot: For example, I seem to have saved some
> seconds by masking lvm.service (I don't use LVM at all). But that
> won't explain why systemd is actually slower on this stage of boot vs.
> the old SysV init some distro versions ago.
>
> Can someone enlighten me?
>
> Greetings
> Stefan
>
> [1] http://imgur.com/3U4tg
> _______________________________________________
> systemd-devel mailing list
> systemd-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/systemd-devel
>

-- 
Gustavo Sverzut Barbieri
http://profusion.mobi embedded systems
--------------------------------------
MSN: barbieri at gmail.com
Skype: gsbarbieri
Mobile: +55 (19) 9225-2202
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/systemd-devel/attachments/20111127/3e1d48f9/attachment.htm>


More information about the systemd-devel mailing list