[asterisk-dev] Proposal for DAHDI-trunk: deprecate old kernels

[Tzafrir Cohen]

Short version: it's now time to remove.

Anybody actually uses latest DAHDI with RHEL4?

See inline,

On Thu, Dec 29, 2011 at 07:42:39PM +0200, Oron Peled wrote:
> Hi,
> 
> Currently there's no policy for deprecating support for old kernels
> in DAHDI-linux, so we have all kinds of code monstrosities to
> support anything from prehistoric kernels (2.6.8/9) to the latest
> and greatest.
> 
> I'd like to propose a general policy and then derive a specific
> case for the near future.
> 
> 1. General kernel deprecation policy:
> 
>    * Stable DAHDI branches (no change from current practices):
>      - Newer kernels are supported as long as the branch is
>        supported. Obviously, after that it's in deep freeze.
> 
>      - No deprecation of old kernels. What worked before,
>        would continue to work even if it is used on a very
>        old "Enterprise" distro.

It seems from the thread that there's no interest in maintaining a LTS
branch just for the sake of supporting old kernels.

Thus I suspect that the usual procedure will be used: fix in trunk.
branches (e.g.: 2.5, 2.6) will be supported for a while (monthes?
whatever) and eventually development moves on. No new procedure.

> 
>    * Trunk - Latest kernels are always supported
> 
>    * Trunk - Old kernels:
>      - A deprecation means output a NOTICE(), but still have
>        the code to support the old kernel

I'm not sure there's much benefit in that. People tend to ignore those.

> 
>      - Support removal happens when we decide to remove the
>        old code that support building DAHDI-linux on old kernels.
>        [bloat removal...]
> 
>      - Fast paced distros should be always supported by trunk
>        (Fedora, Debian-testing, Ubuntu, OpenSuse, name your favorite).
>        These distributions have a kernel life-cycle that is short
>        and therefore does not impose maintenance problems for DAHDI-linux.
> 
>      - Kernels for current Stable/"Enterprise" distros would be fully
>        supported.
> 
>      - Kernels for previous Stable/"Enterprise" distros would be
>        deprecated (remember, only on trunk).
> 
>      - After the next DAHDI-linux stable release, the support code
>        for the deprecated versions would be removed from our trunk.
>        [yes, those ugly #ifdefs]
> 

> 2. Let's try to apply this to the near future. As mentioned
>    before, we can safely ignore fast paced distros and focus
>    only on Stable/"Enterprise"/LTS distros.
> 
>    * RHEL/Centos:
>      - References:
>          https://access.redhat.com/support/policy/updates/errata/
>      - Current version: RHEL-6.x (kernel 2.6.32)
>      - Deprecated version: RHEL-5.x (kernel 2.6.18)
>      - Older version: RHEL-4.x (kernel 2.6.9)
>        [End of Regular Life Cycle - 29-Feb-2012]
> 
>    * Suse SLES:
>      - References:
>          http://www.novell.com/linux/releasenotes/i586/SUSE-SLES/11-SP1
>          http://wiki.novell.com/index.php/Kernel_versions
>          http://support.novell.com/lifecycle
> 
>      - Current version: SLES-11 (kernel 2.6.32)
>      - Deprecated version: SLES-10 (kernel 2.6.16)
>        [End of General Support - 12-Apr-2011]
> 
>    * Debian-stable:
>      - References:
>          http://wiki.debian.org/DebianReleases
>          http://wiki.debian.org/Status/Stable
>          http://lists.debian.org/debian-security-announce/2011/msg00238.html
>      - Current version: Debian-6.0.x "Squeeze" (kernel 2.6.26)
>      - Deprecated version: Debian-5.0.x "Lenny" (kernel 2.6.32)
>        [End Of Life - 2-Feb-2012]
> 
>    * Ubuntu-LTS:
>      - References:
>          https://wiki.ubuntu.com/LTS
>          https://wiki.ubuntu.com/Releases
>          http://en.wikipedia.org/wiki/List_of_Ubuntu_releases
>      - Current LTS version: 10.04 "Lucid Lynx" (kernel 2.6.32)
>      - Deprecated version: 8.04 "Hardy Heron" (kernel 2.6.24)
>        [End Of Life (server) - Apr-2013]
> 
> 3. Proposed timeline:
>    * After DAHDI-2.6/2.5 release:
>      Mark 2.6.8/2.6.9 kernel workarounds as deprecated in
>      our trunk. They are only used by RHEL/Centos-4 and
>      Debian-Etch (before oldstable=="lenny")

Not done. As mentioned above: is probably pointless.

> 
>    * 29-Feb-2012:
>      Can drop RHEL-4 support from trunk. At that time the oldest
>      kernel to support would be 2.6.18 (RHEL-5.x)
>      [good bye 2.6.8/2.6.9 quirks]

Ahem. That's now.

What do you think about:
https://gitorious.org/~tzafrir/asterisk-tools/dahdi-linux-tzafrir/commits/remove_before_2618

Removes more than 600 lines, including more than 100 ifdef-s.

> 
>    * After DAHDI-2.7:
>      Can mark 2.6.18 workarounds as deprecated (in our trunk).
>      At that time the oldest (non-deprecated) kernels to support
>      would be 2.6.24 (Ubuntu-8.04).
> 
>    * After DAHDI-2.8:
>      Drop support for 2.6.18 kernels.

Those are probably over-optimistic. RHEL is expected to move to the
"Extended Support" phase in 2 years or so,

-- 
               Tzafrir Cohen
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