Gentoo Archives: gentoo-dev

From: Richard Yao <ryao@g.o>
To: "Michał Górny" <mgorny@g.o>
Cc: gentoo-dev@l.g.o, "Chí-Thanh Christopher Nguyễn" <chithanh@g.o>
Subject: Re: [gentoo-dev] Changing order of default virtual/udev provider
Date: Wed, 17 Feb 2016 13:39:55
Message-Id: 6C4E5BE6-B8D5-4236-9786-80208347438B@gentoo.org
In Reply to: Re: [gentoo-dev] Changing order of default virtual/udev provider by "Michał Górny"
1 > On Feb 17, 2016, at 7:58 AM, Michał Górny <mgorny@g.o> wrote:
2 >
3 > On Wed, 17 Feb 2016 07:53:22 -0500
4 > Richard Yao <ryao@g.o> wrote:
5 >
6 >>> On Feb 17, 2016, at 7:43 AM, Michał Górny <mgorny@g.o> wrote:
7 >>>
8 >>> On Tue, 16 Feb 2016 23:41:33 +0100
9 >>> Chí-Thanh Christopher Nguyễn <chithanh@g.o> wrote:
10 >>>
11 >>>> Alexis Ballier schrieb:
12 >>>>>>> If it's just that, it's not limited to udev, but anything using
13 >>>>>>> kdbus/bus1, and would mean openrc/${favorite init system} will have
14 >>>>>>> to do the same thing anyway. But again, almost 2 years is extremely
15 >>>>>>> old considering all the flux that has been around kbus.
16 >>>>>>
17 >>>>>> OpenRC itself can for now just ignore kdbus, bus1, or whatever kernel
18 >>>>>> IPC system comes next.
19 >>>>>
20 >>>>> Well, as Lennart wrote it, kbus would have needed some initialisation.
21 >>>>> Just like we have a dbus init script, openrc would have a kdbus one.
22 >>>>>
23 >>>>>> But if upstream udev makes use of the systemd
24 >>>>>> userspace interface to the kernel IPC system, then OpenRC would have
25 >>>>>> to implement the same interface in order to have working udev.
26 >>>>>
27 >>>>> As I understand it, a kernel IPC doesn't need systemd to work. udev
28 >>>>> might use wrappers from libsystemd, or libbus1, just like we have
29 >>>>> programs using libv4l or libbluetooth currently.
30 >>>>
31 >>>> In a follow-up, upstream wrote about how you should only run udev together
32 >>>> with systemd, and if you don't want to do that (spelling as in original):
33 >>>>
34 >>>> "we will not support the udev-on-netlink case anymore. I see three options:
35 >>>> a) fork things, b) live with systemd, c) if hate systemd that much, but
36 >>>> love udev so much, then implement an alternative userspace for kdbus to
37 >>>> do initialiuzation/policy/activation."
38 >>>> https://lists.freedesktop.org/archives/systemd-devel/2014-May/019664.html
39 >>>>
40 >>>> So it seems a bit more than only initialization is needed.
41 >>>
42 >>> You're missing the third option which is a sane option, and jump
43 >>> straight to pitchforks.
44 >>>
45 >>> As I see it, *if* this becomes a necessity, we're quite like are going
46 >>> to provide KDBUS parts of systemd the way we provide udev parts right
47 >>> now. After all, libsystemd-bus will be useful to more applications.
48 >>>
49 >>> Of course, someone may want to fork that into libebus just for the sake
50 >>> of renaming.
51 >>>
52 >>> And after all, as it has already been noted, there are people
53 >>> interested in maintaining non-systemd userspace for KDBUS. Which is
54 >>> kinda the obvious choice, unlike forking something.
55 >>
56 >> kdbus is dead. It is fatally flawed and Greg is no longer trying to get it merged as he is not updating his branch for newer kernel versions. If I recall correctly, kdbus was also removed from Fedora and has no distribution backing it anymore.
57 >
58 > Then... why are we even discussing this?
59
60 I have no idea why we are even discussing the choice of default for virtual/udev to have subdiscussions about kdbus. Practically everyone on the list thinks eudev is the best choice. From the perspective of the Linux community going forward through docker, eudev is the only sensible choice for a udev-based system for those that want to use the same code everyone else uses.
61
62 All arguments about systemd are akin to arguments about how Windows 10 is the next thing in desktops in a world dominated by POSIX through iOS and Android. Coincidentally, neither use systemd.

Replies

Subject Author
Re: [gentoo-dev] Changing order of default virtual/udev provider Ben Kohler <bkohler@×××××.com>