LinuxMusicians

raboof wrote:

Linuxmusician01 wrote:On my current system (Mint 17.1 'Rebecca') I cannot install jack_control and it is not installed. But on my "toy" (antique little laptop) with Debian 10 'Buster' it is installed. How did y'all install jack_control?

I think Mint is Debian-based as well right? Then a useful tool is 'apt-file': 'apt-file jack_control' shows this tool is in the jackd2 package.

Thanks for the tip! I don't know why I couldn't find it in Mint (indeed, Debian based) before? It appears to be already installed on my system today (indeed, via the jackd2 package).

P.S. How can I check on a running instance of Jack how many ports it is using?

Nachei wrote:any idea of what they could mean?

They all happen within a second, so I think this is simply part of the process of shutting down JACK. Nothing to worry about.

Linuxmusician01 wrote:How can I check on a running instance of Jack how many ports it is using?

Go by what JACK was started with. As far as I know there isn't a way to get the JACK server to output this value. Also if you're using jackd I don't think jack_control will do anything. My understanding is that jack_control writes to ~/.config/jack/conf.xml, which is only used by jackdbus.

merlyn wrote:

Nachei wrote:any idea of what they could mean?

They all happen within a second, so I think this is simply part of the process of shutting down JACK. Nothing to worry about.

Yup, I've been using my system some more these days and it's rock solid (I'm able to record midi drums LIVE for the first time ever!), so I don't even pay attention to those messages any more... Thank you again merlyn.

merlyn wrote:

Nachei wrote:any idea of what they could mean?

They all happen within a second, so I think this is simply part of the process of shutting down JACK. Nothing to worry about.

Linuxmusician01 wrote:How can I check on a running instance of Jack how many ports it is using?

Go by what JACK was started with. As far as I know there isn't a way to get the JACK server to output this value. Also if you're using jackd I don't think jack_control will do anything. My understanding is that jack_control writes to ~/.config/jack/conf.xml, which is only used by jackdbus.

Thanks for the info. Always difficult to deal with: jack, dbus and jackd.

@Linuxmusician01 : You could work out how many ports are being used from the amount of memory JACK has allocated.
82280346 bytes is 2048 ports.

merlyn wrote:@Linuxmusician01 : You could work out how many ports are being used from the amount of memory JACK has allocated.

Code: Select all

$ ls -l /dev/shm
total 80444
-rw-r--r-- 1 merlyn merlyn 82280346 Aug 27 11:09 jack-1000-0
-rw-r--r-- 1 merlyn merlyn     1187 Aug 27 11:09 jack-1000-1
srwxr-xr-x 1 merlyn merlyn        0 Aug 27 11:09 jack_default_1000_0
-rwxr-xr-x 1 merlyn merlyn       12 Aug 27 11:09 jack_sem.1000_default_catia
-rwxr-xr-x 1 merlyn merlyn       12 Aug 27 11:09 jack_sem.1000_default_dbusapi
-rwxr-xr-x 1 merlyn merlyn       12 Aug 27 11:09 jack_sem.1000_default_freewheel
-rwxr-xr-x 1 merlyn merlyn       12 Aug 27 11:09 jack_sem.1000_default_system
-rw-rw-rw- 1 merlyn merlyn    70744 Aug 27 10:54 jack-shm-registry

82280346 bytes is 2048 ports.

Thanks! How do you come up with that number? Divide it by 40176?

17374746 bytes is 128 ports, so it's not mem = k * ports, it's something like mem = k * ports + c.

OK, I'll work it out

k * 128 + c = 17374746 --- (1)

k * 2048 + c = 82280346 --- (2)

(2) - (1)

1920 * k = 64905600

k = 33805

sub in (1)

c = 17374746 - 4327040 = 13047706

So the equation is : mem = 33805 * ports + 13047706

so

ports = (mem - 13047706)/33805

merlyn wrote:17374746 bytes is 128 ports, so it's not mem = k * ports, it's something like mem = k * ports + c.

OK, I'll work it out

k * 128 + c = 17374746 --- (1)

k * 2048 + c = 82280346 --- (2)

(2) - (1)

1920 * k = 64905600

k = 33805

sub in (1)

c = 17374746 - 4327040 = 13047706

So the equation is : mem = 33805 * ports + 13047706

so

ports = (mem - 13047706)/33805

Again: thanks! I'm a Master in physical chemistry so I appreciate equations very much. Irritating question once again (please forgive me): how did you come up w/ the number of 17374746?

By the way, on my Raspberry Pi running on Raspbian I got rid of the error "cannot allocate memory" by following the instructions this link. Add to /etc/security/limits.conf:

Linuxmusician01 wrote:how did you come up w/ the number of 17374746?

It's from my verbose JACK log. See this post : https://www.linuxmusicians.com/viewtopi ... 34#p109364. I could also have got it from ls -l /dev/shm

I knew the number of ports from my Cadence settings.

Linuxmusician01 wrote:By the way, on my Raspberry Pi running on Raspbian I got rid of the error "cannot allocate memory" by following the instructions this link. Add to /etc/security/limits.conf:

Code: Select all

   your_user_name        soft      rtprio      90
   your_user_name        soft      memlock      unlimited

   @audio        hard      rtprio      90
   @audio        hard      memlock      unlimited
 
   @video        hard      rtprio      90
   @video        hard      memlock      unlimited

The problem that @Nachei was having was that these changes had been made to limits.conf and he was still getting 'cannot allocate memory'. It's a bug in systemd 240 where user defined limits are ignored. It's still possible to lock memory but the bug means that there is a limit of around 50MB. 1024 ports involves around 47MB of memory, so 1024 ports works.

@Merlyn: thank you for the explanation!