udev minimum requirement

udev minimum requirement

[Darcoux Christine]

Hi,

I am a little confused about the minimum kernel version need for udev .
Is there a contradiction between these two sentences from the README file ?

"The upstream udev project's set of default rules may require a most recent
kernel release to work properly. This is currently version 2.6.31."

and

"Requirements:
  - Version 2.6.27 of the Linux kernel"

Does it means that the **real** minimum requirement is kernel 2.6.31 ?
If not, what will works with 2.6.31 that will not work with 2.6.27 ?

Christine

Re: udev minimum requirement

[Kay Sievers]

On Tue, Jan 18, 2011 at 18:25, Darcoux Christine <bouloumag@gmail.com> wrote:
> I am a little confused about the minimum kernel version need for udev .
> Is there a contradiction between these two sentences from the README file ?
>
> "The upstream udev project's set of default rules may require a most recent
> kernel release to work properly. This is currently version 2.6.31."

That's what we usually test and should work out-of-the-box.

> and
>
> "Requirements:
>  - Version 2.6.27 of the Linux kernel"

That's the first version of the old kernels that has all the
requirement to just run udev. It may fail completely with older
versions. But nobody really tests that, I guess, at least not
constantly. Rules may be missing. Many possible issues could be worked
around, are might not be to find in the udev source tree.

> Does it means that the **real** minimum requirement is kernel 2.6.31 ?
> If not, what will works with 2.6.31 that will not work with 2.6.27 ?

Nobody really knows, I guess, because we usually don't run old kernels
on new userspace tools. We only make sure that new kernels can run on
old userspace, not the other way around.

Kay

Re: udev minimum requirement

[Darcoux Christine]

2011/1/18 Kay Sievers <kay.sievers@vrfy.org>:
> On Tue, Jan 18, 2011 at 18:25, Darcoux Christine <bouloumag@gmail.com> wrote:
>> I am a little confused about the minimum kernel version need for udev .
>> Is there a contradiction between these two sentences from the README file ?
>>
>> "The upstream udev project's set of default rules may require a most recent
>> kernel release to work properly. This is currently version 2.6.31."
>
> That's what we usually test and should work out-of-the-box.
>
>> and
>>
>> "Requirements:
>>  - Version 2.6.27 of the Linux kernel"
>
> That's the first version of the old kernels that has all the
> requirement to just run udev. It may fail completely with older
> versions. But nobody really tests that, I guess, at least not
> constantly. Rules may be missing. Many possible issues could be worked
> around, are might not be to find in the udev source tree.
>
>> Does it means that the **real** minimum requirement is kernel 2.6.31 ?
>> If not, what will works with 2.6.31 that will not work with 2.6.27 ?
>
> Nobody really knows, I guess, because we usually don't run old kernels
> on new userspace tools. We only make sure that new kernels can run on
> old userspace, not the other way around.
>
> Kay
>

(sorry I did not replyed to the list)
Thank you Kay for the explanations. May I suggest to include them in
the readme ?

Cheers