Re: [GIT PULL] kdbus for 4.1-rc1

From: Harald Hoyer
Date: Wed Apr 29 2015 - 11:07:43 EST

On 29.04.2015 16:46, Austin S Hemmelgarn wrote:
> On 2015-04-29 10:11, Harald Hoyer wrote:
>> On 29.04.2015 16:04, Richard Weinberger wrote:
>>> Am 29.04.2015 um 16:01 schrieb Harald Hoyer:
>>>> On 29.04.2015 15:46, Richard Weinberger wrote:
>>>>> Am 29.04.2015 um 15:38 schrieb Harald Hoyer:
>>>>>> On 29.04.2015 15:33, Richard Weinberger wrote:
>>>>>>> It depends how you define "beginning". To me an initramfs is a *very*
>>>>>>> minimal
>>>>>>> tool to prepare the rootfs and nothing more (no udev, no systemd, no
>>>>>>> "mini distro").
>>>>>>> If the initramfs fails to do its job it can print to the console like
>>>>>>> the kernel does if it fails
>>>>>>> at a very early stage.
>>>>>> Your solution might work for your small personal needs, but not for our
>>>>>> customers.
>>>>> Correct, I don't know your customers, all I know are my customers. :-)
>>>>> What feature do your customers need?
>>>>> I mean, I fully agree with you that an initramfs must not fail silently
>>>>> but how does dbus help there? If it fails to mount the rootfs there is not
>>>>> much it can do.
>>>>> Thanks,
>>>>> //richard
>>>> We don't handcraft the initramfs script for every our customers, therefore we
>>>> have to generically support hotplug, persistent device names, persistent
>>>> interface names, network connectivity in the initramfs, user input handling
>>>> for
>>>> passwords, fonts, keyboard layouts, fips, fsck, repair tools for file systems,
>>>> raid assembly, LVM assembly, multipath, crypto devices, live images, iSCSI,
>>>> FCoE, all kinds of filesystems with their quirks, IBM z-series support, resume
>>>> from hibernation, [â]
>>> This is correct. But which of these tools/features depend on dbus?
>> I would love to add dbus support to all of them and use it, so I can connect
>> them all more easily. No need for them to invent their own version of IPC,
>> which can only be used by their own tool set.
> Resume is built into the kernel, so no need for IPC there. Keymaps, fonts, and
> fsck need no IPC either. FIPS related stuff should need no IPC. Anything to
> do with the Device Mapper and hotplug should just need uevents. While I can
> kind of see you wanting to have lvmetad in the initramfs for use with LVM, I've
> seen all kinds of reports of issues caused by that. I can also kind of
> understand wanting some kind of unified IPC for the netboot related stuff, DBus
> is still serious overkill for any of that IMHO. As things stand currently, the
> few things in that list that I know actually use IPC for anything get by just
> fine (and much faster) using just UDS.

He asked what customers need, because he does not need udev, systemd, "mini

Most of the stuff does not work without udev and something like systemd.

And all of the stuff I mentioned together forms a "mini distro" for me.
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