ulimit issues in maverick

[jay105]

hey guys

upgraded to maverick and really actually quite like it. my problem is when i came to set it up for audio work. i downloaded the stuido audio package through synaptic, but when i load up ardour it greys out and become unresponsive. i messed with some jackqtl settings but that didnt fix it. i googled my problem and found the command

ulimit -l

which is to check the memory available to lock down. it came out at 64 , thats kilobytes! i then tried ulimit -l unlimited to boost it to usable levels, only to get james@james-desktop:~$ ulimit -l unlimited
bash: ulimit: max locked memory: cannot modify limit: Operation not permitted
. i tried sudo before, root, loads of other things but no good. any ideas?

[Rubberman]

By memory to lock down, do you mean shared memory? In that case, you need to go to /proc/sys/kernel and "sudo echo max-val >shmmax" to increase max shared memory for your system. On my 9.04 (Jaunty) system shmmax is 33554432, but on 10.10 (Maverick) it is only 2M, and that is on the same hardware, so a lot of audio/video stuff needs to be tweaked to run - had that problem with Cinelerra.

[jay105]

hi rubberman

thanks for the reply! i did what you said, but permission was denied. any idea why this is and how to get around it?

[Rubberman]

You need to do this as root, or using "sudo", provided your account is a sudo user.

[jay105]

yeah, sudo was used...same output! i do however (after inputting my password) get no output sometimes, and then run the ulimit -l command again to find no change.

any ideas?

[Rubberman]

1. Ulimit is context relative. Ie, login, set ulimit, logout, login - ulimit is now back to original settings.
2. The shared memory set as I showed previously by increasing the value of /proc/sys/kernel/shmmax is not reflected in ulimit. This is a different system parameter and is globally applied across the system.

If you need ulimit to be set automatically for you all the time, then set it in your login profile such as ~/.bash_profile

[jay105]

1. Ulimit is context relative. Ie, login, set ulimit, logout, login - ulimit is now back to original settings.
2. The shared memory set as I showed previously by increasing the value of /proc/sys/kernel/shmmax is not reflected in ulimit. This is a different system parameter and is globally applied across the system.

If you need ulimit to be set automatically for you all the time, then set it in your login profile such as ~/.bash_profile

cheers for the help, to clarify, it doesn't seem to be an issue with shmmax, there is a screenshot below as to what i see when i open up ardour, before everything greys out and becomes unresponsive. hopefully it can indicate the problem.



Uploaded with ImageShack.us

[Rubberman]

cheers for the help, to clarify, it doesn't seem to be an issue with shmmax, there is a screenshot below as to what i see when i open up ardour, before everything greys out and becomes unresponsive. hopefully it can indicate the problem.

Well, I think it is quite clear. You need to update the file /etc/security/limits.conf to increase the amount of locked memory (memlock) and then reboot. Here is the manpage for limits.conf:

LIMITS.CONF(5)                 Linux-PAM Manual                 LIMITS.CONF(5)

NAME
       limits.conf - configuration file for the pam_limits module

DESCRIPTION
       The syntax of the lines is as follows:

       <domain><type><item><value>

       The fields listed above should be filled as follows:

       <domain>

              ·  a username

              ·  a groupname, with @group syntax. This should not be confused with netgroups.

              ·  the wildcard *, for default entry.

              ·  the wildcard %, for maxlogins limit only, can also be used with %group syntax.

       <type>

              hard   for enforcing hard resource limits. These limits are set by the superuser and enforced
                     by the Kernel. The user cannot raise his requirement of system resources above such
                     values.

              soft   for enforcing soft resource limits. These limits are ones that the user can move up or
                     down within the permitted range by any pre-exisiting hard limits. The values specified
                     with this token can be thought of as default values, for normal system usage.

              -      for enforcing both soft and hard resource limits together.

                     Note, if you specify a type of ’-’ but neglect to supply the item and value fields then
                     the module will never enforce any limits on the specified user/group etc. .

       <item>

              core   limits the core file size (KB)

              data   maximum data size (KB)

              fsize  maximum filesize (KB)

              memlock
                     maximum locked-in-memory address space (KB)

              nofile maximum number of open files

              rss    maximum resident set size (KB) (Ignored in Linux 2.4.30 and higher)

              stack  maximum stack size (KB)

              cpu    maximum CPU time (minutes)

              nproc  maximum number of processes

              as     address space limit

              maxlogins
                     maximum number of logins for this user

              maxsyslogins
                     maximum number of logins on system

              priority
                     the priority to run user process with (negative values boost process priority)

              locks  maximum locked files (Linux 2.4 and higher)

              sigpending
                     maximum number of pending signals (Linux 2.6 and higher)

              msqqueue
                     maximum memory used by POSIX message queues (bytes) (Linux 2.6 and higher)

              nice   maximum nice priority allowed to raise to (Linux 2.6.12 and higher)

              rtprio maximum realtime priority allowed for non-privileged processes (Linux 2.6.12 and
                     higher)

       In general, individual limits have priority over group limits, so if you impose no limits for admin
       group, but one of the members in this group have a limits line, the user will have its limits set
       according to this line.

       Also, please note that all limit settings are set per login. They are not global, nor are they
       permanent; existing only for the duration of the session.

       In the limits configuration file, the ’#’ character introduces a comment - after which the rest of
       the line is ignored.

       The pam_limits module does its best to report configuration problems found in its configuration file
       via syslog(3).

EXAMPLES
       These are some example lines which might be specified in /etc/security/limits.conf.

       *               soft    core            0
       *               hard    rss             10000
       @student        hard    nproc           20
       @faculty        soft    nproc           20
       @faculty        hard    nproc           50
       ftp             hard    nproc           0
       @student        -       maxlogins       4

SEE ALSO
       pam_limits(8), pam.d(5), pam(8)

AUTHOR
       pam_limits was initially written by Cristian Gafton <gafton@redhat.com>

Linux-PAM Manual                  11/01/2010                    LIMITS.CONF(5)