Re: It is correct to introduce new sys calls to stable versions?

["Theodore Ts'o" <tytso@mit.edu>]

On Tue, Aug 20, 2024 at 09:49:59PM +0800, Miao Wang wrote:
> 
> I agree with you and Cyril on the version numbers, recalling that kernels
> on RHEL numbered on 3.10 contains various new features.

Some enterprise kernel versions have also been known to completely
take code whole from some subsystem (like, for example, a file system
like ext4 or xfs) from much newer upstream kernel version and backport
it into a very old "enterprise" kernel, with massive work to deal with
the dependencies that might be needed by the newer code, and
additional massive work so that structures and function signatures
stay the same so that binary out-of-tree kernel modules can continue
to load on that "stable" enterprise kernel.

That might take huge amounts of effort from a quality assurance
perspective, but that's might some enterprise customers are willing to
pay $$$$ for that frankenkernel and support for that frankenkernel....

This is also why when I get a bug report relating a distro kernel, I
tell bug reporters to go back to the distro for support.  Basically,
you can't really take anything for granted when you're dealing with a
non-upstream kernel, and that includes the version number.
Personally, I think this is a really bad idea, but distros and their
customers have the freedom to do what they want.  And this is why
those customers pay the distro the big bucks.  :-)

    	      	    	    	- Ted