From the ALSA wiki
As of October the pam package 0.79-4 is in Debian unstable, which already includes the rtlimits patch. So the packages at seite9.de should no longer be used.
With any recent Linux system all you should need to do is adding the following lines to /etc/security/limits.conf (the location may vary, depending on your distribution):
@audio - rtprio 99 @audio - memlock 250000 @audio - nice -10
This would give all users in the group audio realtime privileges. You might want to adjust the different values, particularly memlock.
I have put up a new version of the patched pam package for Debian unstable at http://seite9.de/~burkhard/pam_debian_rlimits/. It works for me, but use it at your own risk.
Eric Dantan Rzewnicki writes on the linux-audio-user-mailing-list:
There are also pam debs for sarge here: http://techweb.rfa.org/debrfa/dists/sarge/main/binary-i386/
I am using Debian unstable and the files from the link below did not work for me (the package would not build). Thus I patched the sources myself and built a custom pam-package. As I spent quite some time on figuring this out, I provide my package here in the hope that it will save you some work:
Just get libpam-modules_0.76-24_i386.deb and do dpkg -i. In case you want to build the package yourself, grab the diff-, orig- and dsc-files and do:
tar xvzf pam_0.76.orig.tar.gz gzip -d pam_0.76-24.diff.gz patch -p0 < pam_0.76-24.diff mv pam-0.76.orig/ pam-0.76 cd pam-0.76/ chmod u+x debian/rules sudo apt-get install fakeroot sudo apt-get build-dep pam dpkg-buildpackage -rfakeroot sudo dpkg -i ../libpam-modules_0.76-24_i386.deb
Of course, you use these files at your own risk. They work for me, with a recent Debian unstable (from yesterday). The current Debian version of pam is 0.76-23. The configuration file you might want to tweak is
/etc/security/limits.conf, but I believe the defaults are sensible. Eventually you might also be interested in how I created this package in detail.
A huge thank you Burkhard!!
Fernando (CCRMA) wrote to LAU with these two patches for Fedora systems saying: If this is for fedora core then I have a patched pam in Planet CCRMA... I'm including the patches as attachments (you may want to change the default settings). Beware that if you change the maximum rtpriority allowed to less than 100 you need a patch for 2.6.12, if has a bug in that code section (I don't have a patch, I just use 100 as the max which was the behavior of the previous lsm kernel module).
There are some notes how to use real-time limits here;
I cannot believe how difficult it is to find any decent information about how to deal with such a basic and essential part of the linux audio tool chain. Apparently the PAM patches are available from here, at least for Debian users:
Seed page, please add information of this vital topic - Mark Constable