[linux-audio-user] rlimit problem on opensuse 10.0 - maybe first part of a solution

[Thomas Kuther]

On Fri, 06 Jan 2006 01:01:51 +0100
Joern Nettingsmeier <nettings at folkwang-hochschule.de> wrote:

> hi everyone!
> 
> 
> after some time of job-induced absence from audio work, i have tried
> to bring my audio workstation up to date again.
> 
> the problem is that i can't get realtime privileges.
> 
> arch is x86_64, distro is opensuse 10.0, i'm using the distro kernel, 
> which is a 2.6.13 with additional patches.
> 
> my /etc/security/limits.conf:
> 
> @realtime       -       memlock         128000
> @realtime       -       nice            10
> @realtime       -       rtprio          70
> 
> the account i use is member of @realtime.
> 
> on login, i get
> 
> Jan  6 00:01:38 kleineronkel pam_limits[13812]: unknown limit item
> 'nice' Jan  6 00:01:38 kleineronkel pam_limits[13812]: unknown limit
> item 'rtprio'
> 

Hi people!

I finally got pam rt rlimits working, using pam 0.78 + rlimits patch on
a gentoo system. Jack starts fine in realtime. rt-lsm not loaded.

But there are some questions i'd like to ask, well.. one that is. And i
think this might also be the issue mentioned here.

all docs around the net tell that one has to set following in
limits.conf:
@audio       -       memlock     250000
@audio       -       nice            -10
@audio       -       rtprio          100

..or @audio whatever. now i also got that unknown item 'rtprio' on
login from pam.

looking at the patch i found the following:

@@ -293,6 +298,10 @@
     else if (strcmp(lim_item, "locks") == 0)
        limit_item = RLIMIT_LOCKS;
 #endif
+    else if (strcmp(lim_item, "rt_priority") == 0)
+       limit_item = RLIMIT_RTPRIO;
+    else if (strcmp(lim_item, "nice") == 0)
+       limit_item = RLIMIT_NICE;
     else if (strcmp(lim_item, "maxlogins") == 0) {
        limit_item = LIMIT_LOGIN;


now even i'm not a coder, rtprio is infact called rt_priority! that
seems dokumented wrong in limits.conf on opensuse

also i've read that for audio one should set, hehe --> rt_priority to
100, which seems not to make much sense as:

+        case RLIMIT_RTPRIO:
+            if (limit_value > 99)
+               limit_value = 99;
+           if (limit_value < 0)
+               limit_value = 0;
+            break;

^^ 99% is the (stochastical) limit

Maybe that helps some people here! If i got something wrong please
excuse and correct me. At least here it now all seems to work out fine
and also audio apps can now use more than 15% cpu, which is set as
default value in the patch.

Best regards
Tom