Weblog entry #1 for mzilikazi
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#1
Realtime Debian kernel
Posted by mzilikazi on Wed 19 Apr 2006 at 18:29
I'd really like to get busy using jackd in realtime mode. I would rather not run jackd as root for obvious reason, all clients need to be run as root, then all files generated also belong to root etc.
I've read about enabling "POSIX capabilities inheritance," which allows non-root user processes to obtain realtime access but that is apparently also a security risk.
realtime-lsm is a possibility but it fails to build against stock Debian kernel linux-image-2.6.15-1-486 error is:
"Security capabilities not configured as module"
I also believe that realtime-lsm support was dropped some time ago.
I tried Ingo's rt patch (patch-2.6.16-rt17) and attempted to apply it to linux-2.6.16.9 but several hunks fail. What does a guy have to do to get a realtime kernel in Debian?
I've read about enabling "POSIX capabilities inheritance," which allows non-root user processes to obtain realtime access but that is apparently also a security risk.
realtime-lsm is a possibility but it fails to build against stock Debian kernel linux-image-2.6.15-1-486 error is:
"Security capabilities not configured as module"
I also believe that realtime-lsm support was dropped some time ago.
I tried Ingo's rt patch (patch-2.6.16-rt17) and attempted to apply it to linux-2.6.16.9 but several hunks fail. What does a guy have to do to get a realtime kernel in Debian?
Comments on this Entry
Posted by Anonymous (82.71.xx.xx) on Thu 20 Apr 2006 at 10:33
To get good jackd performance, it's generally easier to install a custom Debian distribution than to do all the tweaking yourself. You could try DeMuDi http://demudi.agnula.org/ for i386, or 64 Studio http://64studio.com/ for AMD64.
[ Parent | Reply to this comment ]
Posted by Anonymous (195.23.xx.xx) on Thu 20 Apr 2006 at 13:32
I tried Ingo's rt patch (patch-2.6.16-rt17) and attempted to apply it to linux-2.6.16.9 but several hunks fail. What does a guy have to do to get a realtime kernel in Debian?2.6.16-rt17 has to be patched against 2.6.16 and not against 2.6.16.9.
[ Parent | Reply to this comment ]
or install ubuntu and follow these steps.
The site and setup are quite good, I had issues with the RealTime Kernel stuff because it seems their HID setup was broken. My problem showed itself when booting. I booted into the ubuntu-proper kernel and recompiled the RT one being strict with what was included in the HID stack.
Now it works!
The site and setup are quite good, I had issues with the RealTime Kernel stuff because it seems their HID setup was broken. My problem showed itself when booting. I booted into the ubuntu-proper kernel and recompiled the RT one being strict with what was included in the HID stack.
Now it works!
[ Parent | Reply to this comment ]
Well thanks but if you're going to use Debian....... then why not use Debian? ;)
Anyway, I found the missing piece to the puzzle. While it was simple enough to build the realtime kernel I still had problems with jackd & permissions. All that was needed was a patched libpam-module available here.
http://seite9.de/~burkhard/pam_debian_rlimits/
If you'd rather not use that deb the instructions for patching your own are also there. When installing the new libpam-module be sure to accept the new config file which properly sets up your /etc/security/limits.conf like so:
# limit realtime and memory locking access to users in the group audio
# there is no way to say "allow locking all memory", 4G should be enough
#
* - rt_priority 0
* - nice 0
#
@audio - rt_priority 100
@audio - nice -10
@audio - memlock 4000000
It work's beautifully. :)
Anyway, I found the missing piece to the puzzle. While it was simple enough to build the realtime kernel I still had problems with jackd & permissions. All that was needed was a patched libpam-module available here.
http://seite9.de/~burkhard/pam_debian_rlimits/
If you'd rather not use that deb the instructions for patching your own are also there. When installing the new libpam-module be sure to accept the new config file which properly sets up your /etc/security/limits.conf like so:
# limit realtime and memory locking access to users in the group audio
# there is no way to say "allow locking all memory", 4G should be enough
#
* - rt_priority 0
* - nice 0
#
@audio - rt_priority 100
@audio - nice -10
@audio - memlock 4000000
It work's beautifully. :)
[ Parent | Reply to this comment ]