Compessor lz4

i have this erorrs in dmesg whit new version kenel or systemd

[    2.651513] zswap: default compressor lz4 not available
[    2.651515] zswap: pool creation failed

Does anyone know if it is harmless
or can it be solved?
Thank for help
Cheers

edit
I forgot I have no swap
sorry

if I follow this guide:
https://wiki.archlinux.org/index.php/Zswap#Enable_LZ4_compression_.28faster_than_lzo_and_deflate.2C_less_compression.29

I get the following error just from the indicated command:

1 root@don-pc /home/don # echo 1 > /sys/module/zswap/parameters/enabled      :(
echo: write error: no device matches

Do you have the lz4 package installed?

Do you use swap space on this system?

Do you have a reason to use lz4 over the default lzo?

When running mkinitcpio to rebuild your initramfs does it throw any errors?

Don’t trust me on this one but the wiki contradict itself

If you cat /sys/module/zswap/parameters/enabled it will be either N or Y, not 0 or 1, you can see the defaults with the following command as shown on the wiki page you linked

grep -R . /sys/module/zswap/parameters
----
/sys/module/zswap/parameters/enabled:Y
/sys/module/zswap/parameters/max_pool_percent:25
/sys/module/zswap/parameters/zpool:z3fold
/sys/module/zswap/parameters/compressor:lz4

Try

echo Y > /sys/module/zswap/parameters/enabled
  1. yes
  2. no
  3. nothing
  4. no
    Since this information appeared to me at start I asked if I had to do something.
    Thank @natemaia

To use the lz4 compression algorithm with zswap, add lz4 lz4_compress to the MODULES array in /etc/mkinitcpio.conf and then run

mkinitcpio -p linux

^ That command is for the stock kernel package, if you are using linux-lts, linux-hardened or linux-zen then substitute those names instead.

And I think ArchLabs uses a swap file, check with free -h.

Ok, check your /etc/mkinitcpio.conf and make sure lz4 isn’t used anywhere, as HoaS said above, then check /etc/default/grub for it as well (GRUB_CMDLINE_LINUX), then run (as root)

mkinitcpio -p linux

grub-mkconfig -o /boot/grub/grub.cfg

That should remove the errors during boot, lemme know

This will show any applied kernel parameters even if ArchLabs isn’t controlling the boot process:

cat /proc/cmdline

Thanks guys for your answers.
I wanted to ask you if zswap with 8gb of ram is worth activating it?
Cheers

Hi, @Head_on_a_Stick
But in the wiki they say you have to do these steps, am I wrong?

    Add lz4 lz4_compress to the mkinitcpio#MODULES array.
    Replace the ramdisk environment with a newly generated one:

    # mkinitcpio -g /boot/initramfs.img

    Add zswap.compressor=lz4 to your kernel parameters.

On next reboot, see #Current parameters to check if zswap now uses lz4 as compressor. 

thank

edit
The strange thing is that I added:

 zswap.compressor=lz4 

without updating grub then it does not appear in the Kernel parameters
but if I check boot time load message, it seems to work.

[don@don-pc ~]$ dmesg | grep zswap
[    2.741062] zswap: loaded using pool lz4/z3fold
[don@don-pc ~]$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-linux-zen root=UUID=91a7796a-ed61-4963-9026-4456b3389029 rw quiet pcie_aspm=force libata.noacpi=1 nowatchdog systemd.legacy_systemd_cgroup_controller=true intel_pstate=disable elevator=noop
[don@don-pc ~]$ 

So this step should I do it?
3 Add zswap.compressor=lz4 to your kernel parameters.

On next reboot, see #Current parameters to check if zswap now uses lz4 as compressor.

Where did you add that?

Do you have any swap? Please post the output of free -h.

The installation guide uses mkinicpio -p to generate a new initramfs image and it was written by Arch developers rather than Arch users, unlike the zswap page.

I put zswap.compressor=lz4 on /etc/default/grub.

[don@don-pc ~]$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-linux-zen root=UUID=91a7796a-ed61-4963-9026-4456b3389029 rw quiet pcie_aspm=force libata.noacpi=1 nowatchdog systemd.legacy_systemd_cgroup_controller=true intel_pstate=disable elevator=noop
[don@don-pc ~]$ 

grub:

# GRUB boot loader configuration

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR='ArchLabs'
GRUB_CMDLINE_LINUX_DEFAULT="quiet pcie_aspm=force libata.noacpi=1 nowatchdog systemd.legacy_systemd_cgroup_controller=true intel_pstate=disable elevator=noop zswap.compressor=lz4"
GRUB_CMDLINE_LINUX=
# scsi_mod.use_blk_mq=y dm_mod.use_blk_mq=y

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable booting from LUKS encrypted devices
#GRUB_ENABLE_CRYPTODISK=y

# Uncomment to enable Hidden Menu, and optionally hide the timeout count
#GRUB_HIDDEN_TIMEOUT=5
#GRUB_HIDDEN_TIMEOUT_QUIET=true

# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=auto

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true

# Uncomment and set to the desired menu colors.  Used by normal and wallpaper
# modes only.  Entries specified as foreground/background.
#GRUB_COLOR_NORMAL="light-blue/black"
#GRUB_COLOR_HIGHLIGHT="light-cyan/blue"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/path/to/wallpaper"
#GRUB_THEME="/path/to/gfxtheme"

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

# Uncomment to make GRUB remember the last selection. This requires to
# set 'GRUB_DEFAULT=saved' above.
#GRUB_SAVEDEFAULT="true"

But I didn’t generate the grub, so at the moment zswap.compressor = lz4 isn’t working.

free- h

[don@don-pc ~]$ free -h
              total        used        free      shared  buff/cache   available
Mem:          7,7Gi       2,1Gi       4,7Gi       246Mi       902Mi       5,1Gi
Swap:            0B          0B          0B
[don@don-pc ~]$ 

thank

Remove the components from the initramfs image and the kernel command line options — there’s no point enabling zswap if you don’t have any swap.