[PlanetCCRMA] newer edge kernel on the edge (2.6.11-0.10.rdt) plus pam!

[Fernando Lopez-Lezcano]

Hi all, another edge kernel on the edge for your tasting pleasure. This
one is again released in the "planetedge" repository. Based on
2.6.12-rc4 and realtime preempt 0.7.47-01 and slowly approaching the
rock solid stability target of 2.6.12 (just kidding! :-). 

GOOD NEWS: the rtlimits patch made it to rc4! 

The rtlimits patch was the other alternative to the realtime lsm patch
(by Jack O'Quinn) that enables normal non-root users to have access to
realtime scheduling and memory locking - well, there was a third one by
Con Kolivas also but was deemed material for 2.7.x. There was a long
long discussion in the lkml about this, and it seems that the rtlimits
option has won for now. It was more complicated to use as it needs
changes to user level programs (pam) but was more palatable to the
kernel gurus. At least we will have an access method for realtime
privileges in the stock kernel!

So... this edge kernel does away with the realtime lsm kernel module and
includes, as part of rc4, the rtlimits patch. 

This brings another change. Instead of loading the realtime lsm module
through the rtload startup script we need to customize the pam
(Pluggable Authentication Modules) package to allow access. Installing
planetccrma-core-edge or planetccrma-core-edge-smp or doing a
"dist-upgrade" will also install a new version of pam that has the
correct configuration to recognize the new limits options in the kernel
and configures them so that all users have access to them. 

You can change this very permissive default (same as with the realtime
lsm module) by changing /etc/security/limits.conf, there are example
lines for, for example, only allowing users in a given group access. The
defaults by default allow all users to set realtime priorities of up to
100 (the maximum) and lock up to 4Gbytes of memory (AFAIK there is no
way to say "up to the available memory" so if you have more than 4G and
want to lock it all up you will need to change the defaults :-)

ALSA is still at 1.0.9-0.4.rc3. 

If you want to again mess up your machine you can if you point apt to
the planetedge repository. Use the same url as planetcore, only replace
"planetcore" with "planetedge"...

Enjoy!
-- Fernando