Linux emulation version number

[Alexander Leidinger]

Quoting Boris Samorodov <bsam at ipt.ru> (Fri, 23 Mar 2007 15:38:20 +0300):

> On Fri, 23 Mar 2007 13:11:40 +0100 Divacky Roman wrote:
> > On Fri, Mar 23, 2007 at 11:36:54AM +0100, Alexander Leidinger wrote:
> > > Quoting Boris Samorodov <bsam at ipt.ru> (from Fri, 23 Mar 2007 02:36:37 
> > > +0300):
> > > 
> > > >Hi!
> > > >
> > > >
> > > >The FC6 port doesn't install with linux.osrelease=2.4.2. Assuming that
> > > >FreeBSD supports only two values (2.6.16 is the second one) I use the
> > > >following line at the Makefile:
> > > >-----
> > > >.include <bsd.port.pre.mk>
> > > >
> > > >LINUX_OSRELEASE!=       ${SYSCTL} -n compat.linux.osrelease
> > > >
> > > >.if ${LINUX_OSRELEASE} != "2.6.16"
> > > >IGNORE= supported only for compat.linux.osrelease: 2.6.16
> > > >.endif
> > > >-----
> > > >
> > > >Something similar should be written to pkg-install script for
> > > >packages sake. The Porters Handbook says it's not good to use sysctl.
> > > >But such approach should be used for all upcomming fc6 ports...
> > > >
> > > >What do you think? Thanks.
> > > 
> > > I suggest to do it the other way around:
> > >  .if ${LINUX_OSRELEASE} == "2.4.2"
> > >  IGNORE
> > >  .endif
> 
> > I dont think this is a good idea.... what if someone sets 2.2?
> 
> Should we call them innocent?
> You shouldn't skip Alexander's comments. ;-)

Yes. If someone sets it to 2.2 he gets what he requests (bullshit). The
goal with the port in my opinion is to prevent foot shooting for those
which use the defaults. For those which (think they) know what they do,
we should not put walls into their way.

> > from slightly different topic... I think the version should follow these rules
> 
> > 1) we should choose 2.6.16 as our target (we already did but its not stated much) and
> > implement its FULL functionality, we're almost there lacking basically only the *at syscalls
> > (which are almost here as well). when splice() (native one) is finished we should implement
> > linux_splice() (a trivial wrapper) and switch to 2.6.17 or possibly 18 as our reference linux version.

Sounds good.

> > 2) the osrelease should be set to the number of the kernel the actual FC is shipped with if < 16 oterwise
> > to 16.

I don't agree. The kernel supports version X, so we announce version X.
The linux kernel is not differently in this regard, and nobody
disallows to use a newer kernel on a shipped FC.

> > I plan to lookup what are the major differences between various linux versions and then we can change
> > these numbers cause now I know only about the 2.6.16 and splice in 2.6.17

Great. Please add this info to the wiki then.

> > I think this way we will get most stability because the FCs are tested with the given kernel number
> > and using higher might lower stability (glibc not being tested for this kernel) and lower number
> > might cripple our ability to emulate..

Most likely the glibc will not know about more recent versions of the
kernel.

We can talk about this later in case we stumble over a problem.

> > opinions?
> 
> You may be right. But ATM I think the best default is as Alexander
> has proposed. This may change after you do what you have proposed. ;-)

We should not make this more complicated. The test in the port is
enough to cover the masses.

Bye,
Alexander.

-- 
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	The force is with you young Skywalker, but you are
	not a Jedi yet.
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