[gentoo-dev] udev implementation

[gentoo-dev] udev implementation

[C. Brewer]

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 I tried out the 0.2 version of udev today, and I realize that its way rough 
so early in the development, but I must say I was disappointed with it's 
current implementation ( and the lousy attitude of the udev FAQ "if you don't 
like it stick with devfs" didn't help). Currently I have some small concerns 
about adopting this as a whole ( somewhere on down the line)-

1)The present package consists of a tarball with just about every device node 
you could make (excepting small things like sound, ppp, more than 4 ttyS*'s)
Is this going to be a standard, or will some form of intuitive /dev entries be 
imp'd? IIRC, the tarball is about 1.4k device nodes, and I think I need 100 
on the outside.

2) Since this won't automatically create these nodes ( unless a hotplug event 
occurs), or load the dependent modules, doesn't this seem like a step back to 
the old system, but with a name-mapping steroided hotplug?

3) Don't get me wrong..I'm not flaming the package,and I realize devfs is crap 
as well..but the score is devfsd( crap but makes nodes and loads mods on the 
fly) and udev (maps names and supposedly does stuff with hotplugging that 
hotplug never amounted to.( and is dev'd by the hotplug peeps?ironic)). All 
that aside, what is udev going to do for the desktop? I have devices I could 
swap(USB) but with most comps coming with like 6 usb ports, I cant see more 
than some pendrive swapping at user level. Yeah, I know theres peeps out 
there with 80 pendrives and 8 hot-swappable hdd's, but is this the majority 
of users? For the likely many of us who dont need to swap and have had the 
same hardware on the same nodes that dont ever change..what does udev bring 
to the table?

Forgive me if I've gone delusional.. I was just under the impression that udev 
was going to do everything that devfsd does now _and_ add name mapping, and 
apparently I was wrong. I'm just planning for the future since seeing the 
udev changes going into our init system.. we got no choice about the devfs 
and I feel it's going the same way for udev. I'm not trying to slight the 
obviously hard work that was put into it, but what about choice? to devfs or 
not to devfs? to udev or not to udev? Or is it merely choice with package 
selection, and not with the overall package that is Gentoo?

Criticism appreciated, discussion welcomed, craziness and flames- please pipe 
to /dev/null:)
-- 
Chuck Brewer
Registered Linux User #284015
Get my gpg public key at pgp.mit.edu!! Encrypted e-mail preferred.



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Re: [gentoo-dev] udev implementation

[Jon Portnoy]

On Mon, Oct 20, 2003 at 10:56:19PM -0700, C. Brewer wrote:
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> 
> Forgive me if I've gone delusional.. I was just under the impression that udev 
> was going to do everything that devfsd does now _and_ add name mapping, and 
> apparently I was wrong. I'm just planning for the future since seeing the 
> udev changes going into our init system.. we got no choice about the devfs 
> and I feel it's going the same way for udev. I'm not trying to slight the 
> obviously hard work that was put into it, but what about choice? to devfs or 
> not to devfs? to udev or not to udev? Or is it merely choice with package 
> selection, and not with the overall package that is Gentoo?
> 

You can go without devfs easily.

You do, however, need to boot with gentoo=nodevfs to tell the init 
system you don't want devfs.

The choice is there.

-- 
Jon Portnoy
avenj/irc.freenode.net

--
gentoo-dev@gentoo.org mailing list

Re: [gentoo-dev] udev implementation

[C. Brewer]

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On Monday 20 October 2003 11:17, Jon Portnoy wrote:
>
> You can go without devfs easily.
>
> You do, however, need to boot with gentoo=nodevfs to tell the init
> system you don't want devfs.
>
> The choice is there.

Very true, however, doesn't that basically tell init just to not start the 
daemon? IIRC, the kernel can't be compiled without devfs support or /sbin/rc 
has a tiny fit...
-- 
Chuck Brewer
Registered Linux User #284015
Get my gpg public key at pgp.mit.edu!! Encrypted e-mail preferred.



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Re: [gentoo-dev] udev implementation

[Jon Portnoy]

On Tue, Oct 21, 2003 at 08:14:29AM -0700, C. Brewer wrote:
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> On Monday 20 October 2003 11:17, Jon Portnoy wrote:
> >
> > You can go without devfs easily.
> >
> > You do, however, need to boot with gentoo=nodevfs to tell the init
> > system you don't want devfs.
> >
> > The choice is there.
> 
> Very true, however, doesn't that basically tell init just to not start the 
> daemon? IIRC, the kernel can't be compiled without devfs support or /sbin/rc 
> has a tiny fit...

Unless it's changed recently, gentoo=nodevfs prevents rc from having 
that fit -- I haven't used a devfs-less system in a while, though.

-- 
Jon Portnoy
avenj/irc.freenode.net

--
gentoo-dev@gentoo.org mailing list

Re: [gentoo-dev] udev implementation

[Christian Birchinger]

You're totaly right. udev is really not usable yet. I was happy
when i first saw the planed features. But once i got the
FAQ/Docs i was really disapointed. And this disapointment
increased after i downloaded the tarball.

I highly suggest not moving to udev yet. Even if devfs is marked
obsolete in kernel it's far better than udev which is in alpha
state. Ofcourse one day we will ne forced to adopt udev so it's
not a bad idea to check it out etc. but please don't switch to
it now. It's really not ready and causes far more problems than
devfs.

On Mon, Oct 20, 2003 at 10:56:19PM -0700, C. Brewer wrote:
Content-Description: signed data
>  I tried out the 0.2 version of udev today, and I realize that its way rough 
> so early in the development, but I must say I was disappointed with it's 
> current implementation ( and the lousy attitude of the udev FAQ "if you don't 
> like it stick with devfs" didn't help). Currently I have some small concerns 
> about adopting this as a whole ( somewhere on down the line)-
> 
> 1)The present package consists of a tarball with just about every device node 
> you could make (excepting small things like sound, ppp, more than 4 ttyS*'s)
> Is this going to be a standard, or will some form of intuitive /dev entries be 
> imp'd? IIRC, the tarball is about 1.4k device nodes, and I think I need 100 
> on the outside.
> 
> 2) Since this won't automatically create these nodes ( unless a hotplug event 
> occurs), or load the dependent modules, doesn't this seem like a step back to 
> the old system, but with a name-mapping steroided hotplug?
> 
> 3) Don't get me wrong..I'm not flaming the package,and I realize devfs is crap 
> as well..but the score is devfsd( crap but makes nodes and loads mods on the 
> fly) and udev (maps names and supposedly does stuff with hotplugging that 
> hotplug never amounted to.( and is dev'd by the hotplug peeps?ironic)). All 
> that aside, what is udev going to do for the desktop? I have devices I could 
> swap(USB) but with most comps coming with like 6 usb ports, I cant see more 
> than some pendrive swapping at user level. Yeah, I know theres peeps out 
> there with 80 pendrives and 8 hot-swappable hdd's, but is this the majority 
> of users? For the likely many of us who dont need to swap and have had the 
> same hardware on the same nodes that dont ever change..what does udev bring 
> to the table?
> 
> Forgive me if I've gone delusional.. I was just under the impression that udev 
> was going to do everything that devfsd does now _and_ add name mapping, and 
> apparently I was wrong. I'm just planning for the future since seeing the 
> udev changes going into our init system.. we got no choice about the devfs 
> and I feel it's going the same way for udev. I'm not trying to slight the 
> obviously hard work that was put into it, but what about choice? to devfs or 
> not to devfs? to udev or not to udev? Or is it merely choice with package 
> selection, and not with the overall package that is Gentoo?
> 
> Criticism appreciated, discussion welcomed, craziness and flames- please pipe 
> to /dev/null:)
> -- 
> Chuck Brewer
> Registered Linux User #284015
> Get my gpg public key at pgp.mit.edu!! Encrypted e-mail preferred.
> 
> 



--
gentoo-dev@gentoo.org mailing list

Re: [gentoo-dev] udev implementation

[Jon Portnoy]

On Tue, Oct 21, 2003 at 09:43:13AM +0200, Christian Birchinger wrote:
> You're totaly right. udev is really not usable yet. I was happy
> when i first saw the planed features. But once i got the
> FAQ/Docs i was really disapointed. And this disapointment
> increased after i downloaded the tarball.
> 
> I highly suggest not moving to udev yet. Even if devfs is marked
> obsolete in kernel it's far better than udev which is in alpha
> state. Ofcourse one day we will ne forced to adopt udev so it's
> not a bad idea to check it out etc. but please don't switch to
> it now. It's really not ready and causes far more problems than
> devfs.
> 

As far as I know, there are currently no plans to move to udev as 
default for a while.

We do, however, have to have support for it, especially for archs like 
AMD64 - 2.4.23-pre* removes devfs for AMD64 due to bugs.

I, personally, think udev sucks and will really miss devfs.

-- 
Jon Portnoy
avenj/irc.freenode.net

--
gentoo-dev@gentoo.org mailing list

Re: [gentoo-dev] udev implementation

[Ernst Herzberg]

On Dienstag, 21. Oktober 2003 07:56, C. Brewer wrote:
>  I tried out the 0.2 version of udev today, and I realize that its way
> rough so early in the development, but I must say I was disappointed
> with it's current implementation ( and the lousy attitude of the udev
> FAQ "if you don't like it stick with devfs" didn't help). 
[....]

You should try 'udev 003 release' first ;-)

http://www.ussg.iu.edu/hypermail/linux/kernel/0310.2/0233.html

Still buggy, but....

~Earny


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gentoo-dev@gentoo.org mailing list

Re: [gentoo-dev] udev implementation

[Martin Schlemmer]

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On Tue, 2003-10-21 at 07:56, C. Brewer wrote:
>  I tried out the 0.2 version of udev today, and I realize that its way rough 
> so early in the development, but I must say I was disappointed with it's 
> current implementation ( and the lousy attitude of the udev FAQ "if you don't 
> like it stick with devfs" didn't help). Currently I have some small concerns 
> about adopting this as a whole ( somewhere on down the line)-
> 

Right.

> 1)The present package consists of a tarball with just about every device node 
> you could make (excepting small things like sound, ppp, more than 4 ttyS*'s)
> Is this going to be a standard, or will some form of intuitive /dev entries be 
> imp'd? IIRC, the tarball is about 1.4k device nodes, and I think I need 100 
> on the outside.
> 

Problem is that you need sysfs support, and currently only the scsi and
major block/char devices supports it (no input, sound, etc).

The tarball is only the initial stage, when better support is there (and
I have obviously learned a lot more :), it will be dropped.

> 2) Since this won't automatically create these nodes ( unless a hotplug event 
> occurs), or load the dependent modules, doesn't this seem like a step back to 
> the old system, but with a name-mapping steroided hotplug?
> 

Depends, creating specific entries in /sys/ will also cause these, and
when all drivers support sysfs ....

> 3) Don't get me wrong..I'm not flaming the package,and I realize devfs is crap 
> as well..but the score is devfsd( crap but makes nodes and loads mods on the 
> fly) and udev (maps names and supposedly does stuff with hotplugging that 
> hotplug never amounted to.( and is dev'd by the hotplug peeps?ironic)). All 

Eventually udev will do this as well (for me example, if with new udev,
and not having /sbin/udev in /proc/sys/kernel/hotplug, it auto loads
usb-storage + co, and creates /dev/sdc* [after deleting them of
course]).  You basically just have to think back initial devfs stage =)

> that aside, what is udev going to do for the desktop? I have devices I could 
> swap(USB) but with most comps coming with like 6 usb ports, I cant see more 
> than some pendrive swapping at user level. Yeah, I know theres peeps out 
> there with 80 pendrives and 8 hot-swappable hdd's, but is this the majority 
> of users? For the likely many of us who dont need to swap and have had the 
> same hardware on the same nodes that dont ever change..what does udev bring 
> to the table?
> 

When the driver register, it will still create /sys/ entries, and thus
the nodes you wish for (when it supports sysfs).

> Forgive me if I've gone delusional.. I was just under the impression that udev 
> was going to do everything that devfsd does now _and_ add name mapping, and 
> apparently I was wrong. I'm just planning for the future since seeing the 
> udev changes going into our init system.. we got no choice about the devfs 
> and I feel it's going the same way for udev. I'm not trying to slight the 
> obviously hard work that was put into it, but what about choice? to devfs or 
> not to devfs? to udev or not to udev? Or is it merely choice with package 
> selection, and not with the overall package that is Gentoo?
> 

If you want to do testing, and do not mind the slight issue, go udev -
if not, go devfs for now.


Thanks,

-- 

Martin Schlemmer
Gentoo Linux Developer, Desktop/System Team Developer
Cape Town, South Africa



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Re: [gentoo-dev] udev implementation

[C. Brewer]

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On Tuesday 21 October 2003 1:36, Martin Schlemmer wrote:

> When the driver register, it will still create /sys/ entries, and thus
> the nodes you wish for (when it supports sysfs).

So, eventually, it'll be close to devfs, except that we'll have to load the 
mod manually to get the driver to register the node, instead of the call to 
the node automatically loading the module? 

-- 
Chuck Brewer
Registered Linux User #284015
Get my gpg public key at pgp.mit.edu!! Encrypted e-mail preferred.



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Re: [gentoo-dev] udev implementation

[Mike Frysinger]

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On Tuesday 21 October 2003 17:45, C. Brewer wrote:
> On Tuesday 21 October 2003 1:36, Martin Schlemmer wrote:
> > When the driver register, it will still create /sys/ entries, and thus
> > the nodes you wish for (when it supports sysfs).
>
> So, eventually, it'll be close to devfs, except that we'll have to load the
> mod manually to get the driver to register the node, instead of the call to
> the node automatically loading the module?

i think that's the point of the udev config file in /etc/udev/ ... devfs had a 
similar config file, thats how it knew the device <-> module mapping ...
-mike

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Re: [gentoo-dev] udev implementation

[C. Brewer]

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On Tuesday 21 October 2003 7:33, Mike Frysinger wrote:

> i think that's the point of the udev config file in /etc/udev/ ... devfs
> had a similar config file, thats how it knew the device <-> module mapping
> ... -mike

I see...I had a peek at those, and it just looked like the configs for 
name-mapping and the permissions of the name-mapped devices, I didnt see any 
indication of somehow that these were gonna modprobe the modules, but I 
suppose that could change eventually(if that's in the future plan)...
-- 
Chuck Brewer
Registered Linux User #284015
Get my gpg public key at pgp.mit.edu!! Encrypted e-mail preferred.



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Re: [gentoo-dev] udev implementation

[Martin Schlemmer]

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On Tue, 2003-10-21 at 23:45, C. Brewer wrote:
> On Tuesday 21 October 2003 1:36, Martin Schlemmer wrote:
> 
> > When the driver register, it will still create /sys/ entries, and thus
> > the nodes you wish for (when it supports sysfs).
> 
> So, eventually, it'll be close to devfs, except that we'll have to load the 
> mod manually to get the driver to register the node, instead of the call to 
> the node automatically loading the module? 

Well, in the case if my usb-flash disk, hotplug loads it ...


-- 

Martin Schlemmer
Gentoo Linux Developer, Desktop/System Team Developer
Cape Town, South Africa



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