compat.linux.osrelease behavior

[Roman Divacky]

On Sat, Sep 19, 2009 at 10:36:24PM +0200, Alexander Leidinger wrote:
> On Fri, 18 Sep 2009 15:08:31 +0200 (CEST) Alexander Best
> <alexbestms at math.uni-muenster.de> wrote:
> 
> 
> > hi there,
> > 
> > i have a question regarding the behavior of compat.linux.osrelease.
> > setting it to 2.4.2 sets linuxulator into 2.4 kernel-emulation and
> > 2.6.16 sets it into 2.6 kernel-emulation right?
> 
> Sort of. 2.6.x set's 2.6 mode, and everything else is 2.4 mode. But
> this is AFAIK only a semantic change of some functions. This does not
> disable syscalls which are in 2.6 but not in 2.4.
> 
> > but what happens when compat.linux.osrelease gets set to a different
> > value? ports/Updating entry 20071101 e.g. advises skype users to set
> > compat.linux.osrelease to 2.4.20. does this trigger 2.6
> > kernel-emulation because 2.4.20 > 2.4.2 or are there more than two
> > kernel-emulation layers inside the linuxulator??
> 
> It does not affect the kernel emulation. But the glibc will try to use
> new syscalls.

actually it does change how the kernel emulation works. grep for linux_use26()