Wiki update

How can I make this site better? Let me know what you'd like to see!

Moderators: MattKingUSA, khz

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raboof
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Re: Wiki update

Postby raboof » Wed Jan 02, 2019 5:30 pm

lilith wrote:If I don't have any entry in fstab it is still used as it is in the kernel by default? Can this be checked somehow?

You can check with "mount | grep shm" to see if /dev/shm is available. I'm not sure if JACK tells you whether it is actually using it, but if it's available then it should.

For me "ls -alFh /dev/shm" shows a /dev/shm/jack-1000 "directory", that could be a good hint ;).

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khz
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Re: Wiki update

Postby khz » Wed Jan 02, 2019 5:48 pm

With the shm entry in the fstab he shows me this.

Code: Select all

 ~ $ ls -alFh /dev/shm
insgesamt 79M
drwxrwxrwt  2 root root  240  2. Jan 20:24 ./
drwxr-xr-x 18 root root 4,2K  2. Jan 10:40 ../
-rw-r--r--  1 daw  daw   79M  2. Jan 19:06 jack-1000-0
-rw-r--r--  1 daw  daw  1,2K  2. Jan 19:06 jack-1000-1
srwxr-xr-x  1 daw  daw     0  2. Jan 19:06 jack_default_1000_0=
-rwxr-xr-x  1 daw  daw    12  2. Jan 19:06 jack_sem.1000_default_a2j*
-rwxr-xr-x  1 daw  daw    12  2. Jan 19:06 jack_sem.1000_default_dbusapi*
-rwxr-xr-x  1 daw  daw    12  2. Jan 19:06 jack_sem.1000_default_freewheel*
-rwxr-xr-x  1 daw  daw    12  2. Jan 19:06 jack_sem.1000_default_qjackctl*
-rwxr-xr-x  1 daw  daw    12  2. Jan 19:07 jack_sem.1000_default_REAPER*
-rwxr-xr-x  1 daw  daw    12  2. Jan 19:06 jack_sem.1000_default_system*
-rw-rw-rw-  1 daw  daw   70K  2. Jan 10:41 jack-shm-registry

<EDIT>

Code: Select all

 ~ $ du -h /dev/shm/*
79M   /dev/shm/jack-1000-0
4,0K   /dev/shm/jack-1000-1
0   /dev/shm/jack_default_1000_0
4,0K   /dev/shm/jack_sem.1000_default_a2j
4,0K   /dev/shm/jack_sem.1000_default_dbusapi
4,0K   /dev/shm/jack_sem.1000_default_freewheel
4,0K   /dev/shm/jack_sem.1000_default_qjackctl
4,0K   /dev/shm/jack_sem.1000_default_REAPER
4,0K   /dev/shm/jack_sem.1000_default_system
72K   /dev/shm/jack-shm-registry

Code: Select all

 ~ $ df -h
shm             7,4G    155M  7,2G    3% /dev/shm
tmpfs           7,4G     12K  7,4G    1% /tmp

https://www.cyberciti.biz/tips/what-is-devshm-and-its-practical-usage.html
https://superuser.com/a/1030777</EDIT>

What without the entry?
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
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Re: Wiki update

Postby Jack Winter » Wed Jan 02, 2019 7:48 pm

khz wrote:I have "size" in the fstab to define the maximum RAM usage. The gcc can also occupy 512 GB RAM. I'm wondering if internet RAM wouldn't be the better solution https://www.cs.swarthmore.edu/~newhall/nswap2L.html.


I'm not sure I understand, AFAIK this has nothing to do with gcc, swap space or something like that.

JACK needs to communicate between the client libs and the server and does this via iirc named pipes. This takes at the most a few megabytes. Probably there are some other apps using shm too, but I've never seen anything take up much space in /dev/shm. Sending it out over the network and back would probably be a bad idea..
Reaper/KDE/Archlinux. i7-2600k/16GB + i7-4700HQ/16GB, RME Multiface/Babyface, Behringer X32, WA273-EQ, 2 x WA-412, ADL-600, Tegeler TRC, etc 8) For REAPER on Linux information: https://wiki.cockos.com/wiki/index.php/REAPER_for_Linux

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Re: Wiki update

Postby Jack Winter » Wed Jan 02, 2019 7:50 pm

lilith wrote:I'll take it out completely. As stated somewhere else this is also better for SSD on the long-term.


I don't understand how it could have anything to do with your SSD.
Reaper/KDE/Archlinux. i7-2600k/16GB + i7-4700HQ/16GB, RME Multiface/Babyface, Behringer X32, WA273-EQ, 2 x WA-412, ADL-600, Tegeler TRC, etc 8) For REAPER on Linux information: https://wiki.cockos.com/wiki/index.php/REAPER_for_Linux

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Re: Wiki update

Postby Jack Winter » Wed Jan 02, 2019 7:51 pm

lilith wrote:If I don't have any entry in fstab it is still used as it is in the kernel by default? Can this be checked somehow?


Yes, have a look with "ls /dev/shm"
Reaper/KDE/Archlinux. i7-2600k/16GB + i7-4700HQ/16GB, RME Multiface/Babyface, Behringer X32, WA273-EQ, 2 x WA-412, ADL-600, Tegeler TRC, etc 8) For REAPER on Linux information: https://wiki.cockos.com/wiki/index.php/REAPER_for_Linux

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Re: Wiki update

Postby Jack Winter » Wed Jan 02, 2019 7:56 pm

khz wrote:With the shm entry in the fstab he shows me this.
[code] ~ $ ls -alFh /dev/shm
insgesamt 79M

What without the entry?


Wow, that's quite a lot more than I see, still only 80MB..

Try without the fstab entry and I don't think it will change anything at all.
Reaper/KDE/Archlinux. i7-2600k/16GB + i7-4700HQ/16GB, RME Multiface/Babyface, Behringer X32, WA273-EQ, 2 x WA-412, ADL-600, Tegeler TRC, etc 8) For REAPER on Linux information: https://wiki.cockos.com/wiki/index.php/REAPER_for_Linux

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raboof
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Re: Wiki update

Postby raboof » Wed Jan 02, 2019 8:19 pm

Jack Winter wrote:
lilith wrote:I'll take it out completely. As stated somewhere else this is also better for SSD on the long-term.


I don't understand how it could have anything to do with your SSD.


I suspect what lilith means is if you use RAM-backed storage instead of Disk-backed storage, that might reduce wear and tear on your SSD. So using tmpfs/SHM for transient data instead of your SSD is probably a good idea.

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khz
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Re: Wiki update

Postby khz » Wed Jan 02, 2019 8:21 pm

Jack Winter wrote:Try without the fstab entry and I don't think it will change anything at all.

Without fstab entry I get the same.

Code: Select all

 ~ $ ls -alFh /dev/shm
insgesamt 79M
drwxrwxrwt  2 root root  240  2. Jan 21:07 ./
drwxr-xr-x 18 root root 4,2K  2. Jan 21:03 ../
-rw-r--r--  1 daw  daw   79M  2. Jan 21:03 jack-1000-0
-rw-r--r--  1 daw  daw  1,2K  2. Jan 21:03 jack-1000-1
srwxr-xr-x  1 daw  daw     0  2. Jan 21:03 jack_default_1000_0=
-rwxr-xr-x  1 daw  daw    12  2. Jan 21:03 jack_sem.1000_default_a2j*
-rwxr-xr-x  1 daw  daw    12  2. Jan 21:07 jack_sem.1000_default_ardour*
-rwxr-xr-x  1 daw  daw    12  2. Jan 21:03 jack_sem.1000_default_dbusapi*
-rwxr-xr-x  1 daw  daw    12  2. Jan 21:03 jack_sem.1000_default_freewheel*
-rwxr-xr-x  1 daw  daw    12  2. Jan 21:03 jack_sem.1000_default_qjackctl*
-rwxr-xr-x  1 daw  daw    12  2. Jan 21:03 jack_sem.1000_default_system*
-rw-rw-rw-  1 daw  daw   70K  2. Jan 21:03 jack-shm-registry

Code: Select all

 ~ $ du -h /dev/shm/*
79M   /dev/shm/jack-1000-0
4,0K   /dev/shm/jack-1000-1
0   /dev/shm/jack_default_1000_0
4,0K   /dev/shm/jack_sem.1000_default_a2j
4,0K   /dev/shm/jack_sem.1000_default_ardour
4,0K   /dev/shm/jack_sem.1000_default_dbusapi
4,0K   /dev/shm/jack_sem.1000_default_freewheel
4,0K   /dev/shm/jack_sem.1000_default_qjackctl
4,0K   /dev/shm/jack_sem.1000_default_system
72K   /dev/shm/jack-shm-registry

Code: Select all

 ~ $ df -h
shm             5,9G    102M  5,8G    2% /dev/shm

What I have written is not necessary, yes.
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
    I don't care about the freedom of speech because I have nothing to say.

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khz
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Re: Wiki update

Postby khz » Wed Jan 02, 2019 8:27 pm

raboof wrote:if you use RAM-backed storage instead of Disk-backed storage, that might reduce wear and tear on your SSD.

Yes. shm == RAM

Code: Select all

┌───────────┬──────────────┬────────────────┐
│ /dev/shm  │ always tmpfs │ Linux specific │
├───────────┼──────────────┼────────────────┤
│ /tmp      │ can be tmpfs │ FHS 1.0        │
├───────────┼──────────────┼────────────────┤
│ /var/tmp  │ never tmpfs  │ FHS 1.0        │
└───────────┴──────────────┴────────────────┘

?
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
    I don't care about the freedom of speech because I have nothing to say.

Jack Winter
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Re: Wiki update

Postby Jack Winter » Wed Jan 02, 2019 8:36 pm

raboof wrote:
Jack Winter wrote:I suspect what lilith means is if you use RAM-backed storage instead of Disk-backed storage, that might reduce wear and tear on your SSD. So using tmpfs/SHM for transient data instead of your SSD is probably a good idea.


Yes, but /dev/shm is a tmpfs even if you haven't mounted it so in fstab, it's automatic nowdays, and as all tmpfs by default it gets a maximum of half your ram. I just saw that steam also uses a few MB on it.

Or maybe it's systemd that mounts it automatically, and I've been misled by my system :) I haven't looked at this for years, back then I concluded that it was not an issue that really concerned me. Possibly after so many discussions on the subject I ought to read the kernel documentation again to refresh my memory :)

Still the beauty of using Linux is that we can all do as we want, and I suppose that there is no right way to do anything. Just trying to bring over the POV that this probably is not an issue for most people and that explicitly mounting it doesn't really offer any advantage than changing the max size available. I really don't know many apps that use it, and personally I've never seen it taking up much ram at all. YMMV and all that.
Reaper/KDE/Archlinux. i7-2600k/16GB + i7-4700HQ/16GB, RME Multiface/Babyface, Behringer X32, WA273-EQ, 2 x WA-412, ADL-600, Tegeler TRC, etc 8) For REAPER on Linux information: https://wiki.cockos.com/wiki/index.php/REAPER_for_Linux

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Re: Wiki update

Postby Jack Winter » Wed Jan 02, 2019 8:55 pm

khz wrote:

Code: Select all

 ~ $ df -h
shm             5,9G    102M  5,8G    2% /dev/shm


In fact you made it bigger with the entry in fstab :shock:
Reaper/KDE/Archlinux. i7-2600k/16GB + i7-4700HQ/16GB, RME Multiface/Babyface, Behringer X32, WA273-EQ, 2 x WA-412, ADL-600, Tegeler TRC, etc 8) For REAPER on Linux information: https://wiki.cockos.com/wiki/index.php/REAPER_for_Linux

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Re: Wiki update

Postby khz » Wed Jan 02, 2019 9:33 pm

Jack processes in shm (RAM) is great.
Would be worth a mention in the WIKI,
shm is included by default. :-D
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
    I don't care about the freedom of speech because I have nothing to say.


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