On Tue, May 15, 2012 at 9:21 PM, Greg KH <gregkh@gentoo.org> wrote:
> I know of no such problem with udisks, have you reported them to the
> upstream developers?

As I said, it's just what I hear — perhaps it's the usual retrograde
whining. I should probably just try udisks-glue, the only issue I see
is that it depends on UDisks 1.

> You can stall the whole hotplug path, causing issues and overruns.

Note that the script I mentioned immediately forks, and only updates
autofs mapping entries — it doesn't actually mount anything.

> Right there, if that's all you need, and it's what most embedded systems
> need, udev isn't even needed, just use devtmpfs and all is fine.

Perhaps I wasn't expressing myself clearly — the point was to show
that mdev is not needed. I used mdev in initramfs previously, but now
rely on devtmpfs and the one-liner /sbin/hotplug for loading modules.
Incidentally, turning off mdev resulted in Busybox executable size
change of precisely 0, which I guess shows how much mdev actually
does.

> I really want to get rid of that entry and option from the kernel entirely

Please don't — it's useful in Busybox-based initramfs. Dracut-like
inclusion of udev and its dependencies DAG is usually unnecessary and
an overkill.

--
Maxim Kammerer
Liberté Linux (discussion / support: http://dee.su/liberte-contribute)

On Tue, May 15, 2012 at 02:32:57AM -0400, Olivier Cr?te wrote
> On Tue, 2012-05-15 at 01:05 -0400, Walter Dnes wrote:
> > I *DON'T WANT* "a serious framework", I want a lightweight device
> > manager... period... end of story. Stick with the unix principle of one
> > app doing one thing well. mdev is enough for the vast majority of people.
>
> For the people who don't want to easily use USB sticks or digital
> cameras or gsm dongles or really any modern hardware, I'm sure mdev is
> fine. A static /dev is even fine for you probably.

Huh!?!?!? USB sticks work just fine, thank you, with mdev. I also
regularly backup my mdev-based machine via rsync to an external drive
via USB. And yes my camera does show up as a USB mass storage device.
Ditto for my HTC Desire.

--
Walter Dnes <waltdnes@waltdnes.org>

On Wed, May 16, 2012 at 1:59 AM, Walter Dnes <waltdnes@waltdnes.org> wrote:
> On Tue, May 15, 2012 at 02:32:57AM -0400, Olivier Cr?te wrote
>> On Tue, 2012-05-15 at 01:05 -0400, Walter Dnes wrote:
>> > * I *DON'T WANT* "a serious framework", I want a lightweight device
>> > manager... period... end of story. *Stick with the unix principle of one
>> > app doing one thing well. *mdev is enough for the vast majority of people.
>>
>> For the people who don't want to easily use USB sticks or digital
>> cameras or gsm dongles or really any modern hardware, I'm sure mdev is
>> fine. A static /dev is even fine for you probably.
>
> *Huh!?!?!? *USB sticks work just fine, thank you, with mdev. *I also
> regularly backup my mdev-based machine via rsync to an external drive
> via USB. *And yes my camera does show up as a USB mass storage device.
> Ditto for my HTC Desire.
>

"Those who don't understand UNI^H^H^Hsoftware are condemned to
reinvent it, poorly."

--
~Nirbheek Chauhan

Gentoo GNOME+Mozilla Team

On Tue, May 15, 2012 at 11:26:03AM -0700, Greg KH wrote
> On Tue, May 15, 2012 at 01:55:23AM -0400, Walter Dnes wrote:
> >
> > After some more Google-searching. it looks like the "official
> > channels" way is via /etc/mdev.conf. Note that this is on a system with
> > busybox[mdev] and no udev. /etc/mdev.conf has a rudimentary set of
> > "mdev rules" abilities, and most importantly, it can also call external
> > executables (scripts/programs/whatever). On my mdev based machines...
> >
> > $ cat /proc/sys/kernel/hotplug
> > /sbin/mdev
>
> Oh my, don't do that. Please. It will slow your machine down, and on
> some systems, and devices, cause fork-bombs causing your box to come to
> a crawl and potentially die. There's also ordering issues that the
> called program needs to resolve to get things right that add lots of
> logic and slowdowns at times. I really want to get rid of that entry
> and option from the kernel entirely, but need to keep it due to legacy
> systems and API issues.
>
> But really, don't do that, it's not a good idea at all.

During bootup, mdev is invoked as "mdev -s", and in hotplug mode it's
simply "mdev". In hotplug mode, mdev returns some environmental
variables, specifically "ACTION", which are not returned by "mdev -s".
Any scripts launched by mdev can easily figure out whether they've been
called at bootup or in response to a hotplug event, and act accordingly.
A Google search turns up many hits about instructions for automounting
under mdev, and it appears relatively easy.

> What specifically is your objection to udev today? Is it doing things
> you don't like? Too big? Something else?

Today, it requires an initramfs if /usr is not physically on /. That
is due in large part to the fact that it has been rolled into the
systemd tarball, and inherited some of systemd's code and limitations,
despite the fact that udev is still a separate binary.

That's today. How long before it becomes part of the systemd binary?

--
Walter Dnes <waltdnes@waltdnes.org>

On Tue, 2012-05-15 at 18:38 -0400, Walter Dnes wrote:
> On Tue, May 15, 2012 at 11:26:03AM -0700, Greg KH wrote
> > What specifically is your objection to udev today? Is it doing things
> > you don't like? Too big? Something else?
>
> Today, it requires an initramfs if /usr is not physically on /. That
> is due in large part to the fact that it has been rolled into the
> systemd tarball, and inherited some of systemd's code and limitations,
> despite the fact that udev is still a separate binary.

This is absolutely and definitely false. Where did you hear such
nonsense ?


--
Stelian Ionescu a.k.a. fe[nl]ix
Quidquid latine dictum sit, altum videtur.
http://common-lisp.net/project/iolib

On Wed, May 16, 2012 at 12:44:59AM +0200, Stelian Ionescu wrote
> On Tue, 2012-05-15 at 18:38 -0400, Walter Dnes wrote:
> > On Tue, May 15, 2012 at 11:26:03AM -0700, Greg KH wrote
> > > What specifically is your objection to udev today? Is it doing things
> > > you don't like? Too big? Something else?
> >
> > Today, it requires an initramfs if /usr is not physically on /. That
> > is due in large part to the fact that it has been rolled into the
> > systemd tarball, and inherited some of systemd's code and limitations,
> > despite the fact that udev is still a separate binary.
>
> This is absolutely and definitely false. Where did you hear such
> nonsense ?

1) Did you sleep through the /usr and initramfs flamewars?
http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken

2) The udev sources have merged into the systemd tarball. See...
http://article.gmane.org/gmane.linux.hotplug.devel/17392 And note
the date is April 3rd, not April 1st. If they were really as worried
about compatability as they claim, you wouldn't need to use initramfs
for udev with a separate /usr.

--
Walter Dnes <waltdnes@waltdnes.org>

I asked what I thought was a simple developer-type question. I don't
want this to become a public flamewar. If anybody wants to discuss the
issue with me further, please email directly to me and not the list.

--
Walter Dnes <waltdnes@waltdnes.org>

On Tue, May 15, 2012 at 07:51:03PM -0400, Walter Dnes wrote:
> On Wed, May 16, 2012 at 12:44:59AM +0200, Stelian Ionescu wrote
> > On Tue, 2012-05-15 at 18:38 -0400, Walter Dnes wrote:
> > > On Tue, May 15, 2012 at 11:26:03AM -0700, Greg KH wrote
> > > > What specifically is your objection to udev today? Is it doing things
> > > > you don't like? Too big? Something else?
> > >
> > > Today, it requires an initramfs if /usr is not physically on /. That
> > > is due in large part to the fact that it has been rolled into the
> > > systemd tarball, and inherited some of systemd's code and limitations,
> > > despite the fact that udev is still a separate binary.
> >
> > This is absolutely and definitely false. Where did you hear such
> > nonsense ?
>
> 1) Did you sleep through the /usr and initramfs flamewars?
> http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
>
> 2) The udev sources have merged into the systemd tarball. See...
> http://article.gmane.org/gmane.linux.hotplug.devel/17392 And note
> the date is April 3rd, not April 1st. If they were really as worried
> about compatability as they claim, you wouldn't need to use initramfs

If you saw my last message on this subject, there is no need to use
initramfs if you don't want to use it.

See the sep-usr use flag on the ~arch version of busybox and the
instructions you get when you turn that on.

William

On 16 May 2012 05:21, Walter Dnes <waltdnes@waltdnes.org> wrote:
> On Wed, May 16, 2012 at 12:44:59AM +0200, Stelian Ionescu wrote
>> On Tue, 2012-05-15 at 18:38 -0400, Walter Dnes wrote:
>> > On Tue, May 15, 2012 at 11:26:03AM -0700, Greg KH wrote
>> > > What specifically is your objection to udev today? *Is it doing things
>> > > you don't like? *Too big? *Something else?
>> >
>> > * Today, it requires an initramfs if /usr is not physically on /. *That
>> > is due in large part to the fact that it has been rolled into the
>> > systemd tarball, and inherited some of systemd's code and limitations,
>> > despite the fact that udev is still a separate binary.
>>
>> This is absolutely and definitely false. Where did you hear such
>> nonsense ?
>
> *1) Did you sleep through the /usr and initramfs flamewars?
> http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken

You seem to have missed the bit that this has nothing at all to do with systemd.

--
Arun Raghavan
http://arunraghavan.net/
(Ford_Prefect | Gentoo) & (arunsr | GNOME)

On 15/05/12 21:07, Arun Raghavan wrote:
>> 1) Did you sleep through the /usr and initramfs flamewars?
>> http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
>
> You seem to have missed the bit that this has nothing at all to do with systemd.
>

I guess the systemd in the url might be have people consider it a sort
of tell-tale. It could had been

http://bluez.org/known_issue/separate-usr-problems

Maybe.

--

Luca Barbato
Gentoo/linux
http://dev.gentoo.org/~lu_zero