Re: [GIT PULL] kdbus for 4.1-rc1

David Lang
2015-04-29T16:37:39Z

On Wed, 29 Apr 2015, Martin Steigerwald wrote:

> Am Mittwoch, 29. April 2015, 14:47:53 schrieb Harald Hoyer:
>> We really don't want the IPC mechanism to be in a flux state. All tools
>> have to fallback to a non-standard mechanism in that case.
>>
>> If I have to pull in a dbus daemon in the initramfs, we still have the
>> chicken and egg problem for PID 1 talking to the logging daemon and
>> starting dbus.
>> systemd cannot talk to journald via dbus unless dbus-daemon is started,
>> dbus cannot log anything on startup, if journald is not running, etc...
>
> Do I get this right that it is basically a userspace *design* decision
> that you use as a reason to have kdbus inside the kernel?
>
> Is it really necessary to use DBUS for talking to journald? And does it
> really matter that much if any message before starting up dbus do not
> appear in the log? /proc/kmsg is a ring buffer, it can still be copied over
> later.

I've been getting the early boot messages in my logs for decades (assuming the
system doesn't fail before the syslog daemon is started). It sometimes has
required setting a larger than default ringbuffer in the kernel, but that's easy
enough to do.

David Lang