Re: Linux 4.0-rc1 out..

["François Valenduc" <francoisvalenduc@gmail.com>]

Le 24/02/15 08:40, Christian Borntraeger a écrit :
> Am 24.02.2015 um 03:34 schrieb Mike Galbraith:
>> On Mon, 2015-02-23 at 16:43 +0100, Christian Borntraeger wrote:
>>> Am 23.02.2015 um 04:06 schrieb Linus Torvalds:
>>>> .. let's see how much, if anything, breaks due to the version number.
>>>> Probably less than during the 3.0 timeframe, but I can just imagine
>>>> somebody checking for meaningful versions.
>>>>
>>>> Because the people have spoken, and while most of it was complete
>>>> gibberish, numbers don't lie. People preferred 4.0, and 4.0 it shall
>>>> be. Unless somebody can come up with a good argument against it.
>>>
>>> The only argument that I can come up with is "we do not break userspace".
>>> For example there is this "gem" in configure.ac of valgrind:
>>>
>>>
>>>         case "${kernel}" in
>>>              2.6.*|3.*)
>>>                     AC_MSG_RESULT([2.6.x/3.x family (${kernel})])
>>>                     AC_DEFINE([KERNEL_2_6], 1, [Define to 1 if you're using Linux 2.6.x or Linux 3.x])
>>>                     ;;
>>>
>>>              2.4.*)
>>>                     AC_MSG_RESULT([2.4 family (${kernel})])
>>>                     AC_DEFINE([KERNEL_2_4], 1, [Define to 1 if you're using Linux 2.4.x])
>>>                     ;;
>>>
>>>              *)
>>>                     AC_MSG_RESULT([unsupported (${kernel})])
>>>                     AC_MSG_ERROR([Valgrind works on kernels 2.4, 2.6])
>>>                     ;;
>>
>>
>> Heh, if this is an argument, we have one hell of a lot of reverting to
>> do :)   Crash for example breaks at much higher resolution, and indeed
>> just broke yet again.  Tough titty for userspace methinks.
> 
> Well crash is not a good example as it by design goes beyond the user ABI
> and directly touches the kernel data structures ;-)
> 
> I am not requesting to go back to 3.*, I was just pointing out that if we apply
> strict rules on "we dont break userspace", the move to 3.* and 4.* was a mistake.
> We do provide uname26 as a workaround, so this is ok and the switch to 4 should
> be a lot smoother. 
> 
> But better end the discussion here :-)
> 
> Christian
> 
> FWIW, valgrind svn is fixed as of yesterday (for good, so Linux 5.* 6.*.. should
> also work)
> 
Changing to v4.0 also seems to be a problem either for genkernel, lvm or
cryptsetup. I use LVM on an encrypted root on gentoo and it doesn't work
anymore. However it works if I rename the kernel to 3.20-rc1.

Does anybody has an idea about that ?

Thanks in advance,

François Valenduc