[systemd-devel] How to suppress "A start job is running for offline-updates" knight-rider status output?

[Hans de Goede]

Hi,

On 28-02-19 10:27, Colin Guthrie wrote:
> Hans de Goede wrote on 27/02/2019 19:12:
>> On 27-02-19 17:04, Lennart Poettering wrote:
>>> Another option is to do this in your soruces btw:
>>>
>>> ```c
>>> (void) kill(1, SIGRTMIN+21);
>>> ```
>>>
>>> Sending SIGRTMIN+21 to PID 1 will disable the status output
>>> explicitly. If you are sure you don't want it you can just do that, in
>>> one line.
>>>
>>> Plymouth also sends that signal, hence make sure you don't run into
>>> races with that.
>>
>> That won't work, the primary use-case for the offline-updates
>> status display is a user pressing ESC while plymouth is showing this:
>> https://fedorapeople.org/~jwrdegoede/flickerfree-videos/installing.png
>>
>> So that the user can see details if he/she wants that. In this case
>> plymouth will send SIGRTMIN+22 when switching back to text-mode to
>> have systemd resume its status messages, so having pk-offline-update send
>> SIGRTMIN+21 when it starts will not help.
> 
> Could the plymouth theme somehow suppress the sending of SIGRTMIN+22?
> e.g. in the case of the offline updates it's presumably integrating with
> the pk-offline-update to get progress reports anyway, so it knows the
> context in which it's run. I could simply suppress the sending of
> SIGRTMIN+22 and leave just the pk-offline-update messages?
> 
> Obviously would need a tweak to plymouth, but perhaps it's not too
> crazy? Just a thought.

That only fixes the case when plymouth is running, but we really cannot
assume that that is always the case.

Regards,

Hans