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Old 04-12-2021, 04:28 PM   #16
ZhaoLin1457
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Quote:
Originally Posted by upnort View Post
Is there a way to fully disable cgroups on desktop systems? Or are desktop users stuck with cgroups to one degree or another?

With the changes in Current, the mount command output is populated with significant cgroups spew.

Okay, rc.S provides a clue to avoid that by removing the /etc/mtab sym link to /proc/mounts. rc.S then will create a traditional /etc/mtab file. That reduces mount output spew.

I don't know what issues using /etc/mtab as a file creates. Understandably Pat resisted long but has thrown in the towel although still supporting /etc/mtab as a file. Does that impact the system? I am guessing mostly or probably not for most users otherwise Pat would have written the rc.S snippet to enforce the sym link.

Quieting the mount output is helpful, but the underlying cgroup processes and file systems still exist. This was true with 14.2 too only that /etc/mtab as a file masked that information.

There is a snippet in rc.S to mount the control groups file system interface. That snippet could be commented out to further reduce cgroup spew but not fully.

Avoiding cgroups does not seem possible because elogind seems to be designed with an expectation of cgroups.

There is the kernel boot parameter cgroup_disable, but using that parameter results in udev spew complaints during boot.

There is the option of recompiling the kernel without cgroup support. I don't know how much that breaks the system and I haven't yet tested.

Thanks.
I do not think the CGROUPS are an optional feature for a Linux operating system of today, specially a desktop one.

From what I known, the ConsoleKit, ConsoleKit2, elogind (and systemd-logind) and even the LXC containers or the glorified FlatPaks relies on them for their logic.

Last edited by ZhaoLin1457; 04-12-2021 at 04:33 PM.
 
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Old 04-14-2021, 01:49 AM   #17
walecha
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Quote:
Originally Posted by upnort View Post
I don't know what issues using /etc/mtab as a file creates.
I don't have a problem with /etc/mtab as a file, fully writable file. But I prefer using /etc/mtab as symlink to /proc/mounts or /proc/self/mounts, because in the case when i dropped to init 1 with / being read-only, I still get the right list of mounted partition. It happened once for me, when one of the disk in the RAID cluster gone bad. The partition was forcibly unmounted but /etc/mtab was not updated at the time of disk failure, the data still flow to the mount point dir and filling the / partition. That was a mess. So even before Slackware symlinked /etc/mtab to /proc/mounts, I've done it by my self to avoid similar case.
 
Old 04-14-2021, 09:29 AM   #18
perseus12
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Quote:
Originally Posted by ZhaoLin1457 View Post
I do not think the CGROUPS are an optional feature for a Linux operating system of today, specially a desktop one.

From what I known, the ConsoleKit, ConsoleKit2, elogind (and systemd-logind) and even the LXC containers or the glorified FlatPaks relies on them for their logic.
My use cases on a laptop are different than on my desktop. On the desktop I have no cgroups at all, and even samba has been eradicated. Of course I will never post a question to LQ about a problem on desktop because I know it is not vanilla Slackware. But it can be done (I'll even be on 5.11 kernel!); no elogind, no pam, no samba, no pulseaudio, no network-manager.

I have not and will not complain about these programs simply because I do not use them. I also will not 'brag about my system is better than your system'. But I just want to point out that it can be done with a little of bit of effort upfront and then of course you must maintain the system yourself, but once these removals have been done, future upgrades take care of themselves.

I learned how to do this by following LFS. I guess my point is that I respect peoples opinions but they should be careful of generalizing.

In fact an interesting topic would be to divide Slackware users into quartiles and see the use cases in each one, and then how each user maintains their system. Going back to some recent flamewars here, I would say this is another feature of Slackware in that it allows its users a GREAT flexibility like no other distro. I am a very happy Slackware user because Slackware allows me to fiddle and change Slackware to my heart's content and it still keeps on ticking.

Just my my 00000.1 bitcoin
 
Old 04-14-2021, 10:42 AM   #19
Chuck56
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Quote:
Originally Posted by chrisretusn View Post
...Makes me wonder what other system changes I've missed over the years.
Ditto! A newly deployed mini-pc with current has the symlink to /etc/mtab. All the rest of my current installs pre-date the mtab change and have a file for /etc/mtab.
 
Old 04-15-2021, 10:28 PM   #20
Aeterna
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Quote:
Originally Posted by Chuck56 View Post
Ditto! A newly deployed mini-pc with current has the symlink to /etc/mtab. All the rest of my current installs pre-date the mtab change and have a file for /etc/mtab.
it must be something else than system age. My Slackware host has mtab file. Slackware was created:
Quote:
sudo tune2fs -l /dev/sda1 | grep created
Filesystem created: Mon Nov 19 20:44:24 2018
I created recently a new VM Slackware client:
Quote:
sudo tune2fs -l /dev/sda1 | grep created
Filesystem created: Mon Oct 12 14:39:14 2020
mtab is also a file not symlink
 
Old 04-15-2021, 11:13 PM   #21
bassmadrigal
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Quote:
Originally Posted by Aeterna View Post
it must be something else than system age. My Slackware host has mtab file. Slackware was created:


I created recently a new VM Slackware client:

mtab is also a file not symlink
It should've happened with any new installs after 28 NOV 2018.

Code:
Wed Nov 28 07:25:32 UTC 2018
isolinux/initrd.img:  Rebuilt.
  On a freshly installed system, make /etc/mtab a symlink to /proc/mounts.
That's what happened on my system from May 2019.

Code:
jbhansen@febtober:~$ sudo tune2fs -l /dev/nvme0n1p3 | grep created
Filesystem created:       Tue May 28 19:15:24 2019
jbhansen@febtober:~$ ls -l /etc/mtab
lrwxrwxrwx 1 root root 12 May 28  2019 /etc/mtab -> /proc/mounts
I wonder if something specific on your system changed it without you realizing it.
 
Old 04-16-2021, 09:24 AM   #22
Aeterna
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Quote:
Originally Posted by bassmadrigal View Post
It should've happened with any new installs after 28 NOV 2018.

Code:
Wed Nov 28 07:25:32 UTC 2018
isolinux/initrd.img:  Rebuilt.
  On a freshly installed system, make /etc/mtab a symlink to /proc/mounts.
That's what happened on my system from May 2019.

Code:
jbhansen@febtober:~$ sudo tune2fs -l /dev/nvme0n1p3 | grep created
Filesystem created:       Tue May 28 19:15:24 2019
jbhansen@febtober:~$ ls -l /etc/mtab
lrwxrwxrwx 1 root root 12 May 28  2019 /etc/mtab -> /proc/mounts
I wonder if something specific on your system changed it without you realizing it.
this
Quote:
Wed Nov 28 07:25:32 UTC 2018
isolinux/initrd.img: Rebuilt.
On a freshly installed system, make /etc/mtab a symlink to /proc/mounts.
I don't use initrd and first think I did before upgrade was stripping down default Slackware installation form the software I don't need and building custom kernel without initrd.

For me it does not matter if mtab is file or symlink on my laptop. I bought hardware 7 years ago installed Slackware only twice:
second time only because SSD died and I had to replace it. I can understand though that in some configurations mtab info is vital (as mentioned by @walecha)
 
Old 04-16-2021, 11:04 AM   #23
bassmadrigal
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Quote:
Originally Posted by Aeterna View Post
this

I don't use initrd and first think I did before upgrade was stripping down default Slackware installation form the software I don't need and building custom kernel without initrd.

For me it does not matter if mtab is file or symlink on my laptop. I bought hardware 7 years ago installed Slackware only twice:
second time only because SSD died and I had to replace it. I can understand though that in some configurations mtab info is vital (as mentioned by @walecha)
That's for the installer (isolinux/initrd.img is what you boot when you boot an installation disk), not regular use of an initrd. If you booted off an installation disk from that date on, the installer will set up a symlink during installation. If you installed after that date and don't have it symlinked, then you either used a different installer, something changed it at a later point, or you did something unique in the installer that prevented it (I'm not aware of any options that would prevent it, but I haven't really dug through it).

Last edited by bassmadrigal; 04-16-2021 at 11:05 AM.
 
  


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