arch advance

 sudo nano /etc/pacman.conf

NoExtract = usr/share/dbus-1/services/org.a11y.*

from https://wiki.archlinux.org/title/Pacman/Tips_and_tricks

NoExtract = usr/share/locale/* usr/share/X11/locale/*/* usr/share/i18n/locales/* opt/google/chrome/locales/* !usr/share/X11/locale/C/*
NoExtract = !usr/share/X11/locale/compose.dir !usr/share/X11/locale/iso8859-1/*
NoExtract = !*locale*/en*/* !usr/share/*locale*/locale.*
NoExtract = !usr/share/*locales/en_?? !usr/share/*locales/i18n* !usr/share/*locales/iso*
NoExtract = usr/share/i18n/charmaps/* !usr/share/i18n/charmaps/UTF-8.gz !usr/share/i18n/charmaps/ANSI_X3.4-1968.gz
NoExtract = !usr/share/*locales/trans*
NoExtract = !usr/share/*locales/C !usr/share/*locales/POSIX

du -sh /usr/share/gtk-doc/html/

2.9M

 

du -sh /usr/share/doc/

63M

du -sh /usr/share/locale/

175M    

du -sh /usr/share/X11/locale/

1.6M    

du -sh  /usr/share/i18n/charmaps

3.4M    

du -sh   /usr/share/i18n/locales/

13M    

 

https://github.com/archlinux/archlinux-docker/blob/master/pacman-conf.d-noextract.conf

pacman -Qo  file 

find owner pkg  of file

 

 pacman -S --overwrite

 pacman -Q $(pactree -u pacman)

cd /var/lib/pacman/sync

cd /var/lib/pacman/local 

https://mirrors.tuna.tsinghua.edu.cn/archlinux/core/os/x86_64/core.db

https://mirrors.tuna.tsinghua.edu.cn/archlinux/community/os/x86_64/community.db

https://mirrors.tuna.tsinghua.edu.cn/archlinux/extra/os/x86_64/extra.db

clean cache

dry run  

paccache  -d

keep last 3 pkg  

 paccache -r

to retain only past last version

paccache -rk1

 

remove unisnstalled 

paccache -ruk0

To remove all the cached packages that are not currently installed, and the unused sync database, execute: 

pacman -Sc

To remove all files from the cache, use the clean switch twice, this is the most aggressive approach and will leave nothing in the cache directory: 

pacman -Scc

The list of explicitly-installed packages can be shown with pacman -Qe, while the complementary list of dependencies can be shown with pacman -Qd.

 

To remove a package and its dependencies which are not required by any other installed package:

pacman -Rs

  -c, --cascade        remove packages and all packages that depend on them
  -n, --nosave         remove configuration files
  -p, --print          print the targets instead of performing the operation
  -s, --recursive      remove unnecessary dependencies
                       (-ss includes explicitly installed dependencies)
  -u, --unneeded       remove unneeded packages

      --confirm        always ask for confirmation

 

pacman -Rsu package_name 

 

pacman -S 

  -i, --info           view package information (-ii for extended information)
  -l, --list <repo>    view a list of packages in a repo
  -q, --quiet          show less information for query and search

  -s, --search <regex> search remote repositories for matching strings 

  -u, --sysupgrade     upgrade installed packages (-uu enables downgrades)
  -y, --refresh        download fresh package databases from the server
                       (-yy to force a refresh even if up to date)
      --asdeps         install packages as non-explicitly installed
      --asexplicit     install packages as explicitly installed
      --assume-installed <package=version>
                       add a virtual package to satisfy dependencies
      --ignore <pkg>   ignore a package upgrade (can be used more than once)
      --needed         do not reinstall up to date packages
 

sudo pacman -S --assume-installed python python-pam

 create dummy package to satisfy dependecies

mkdir python-dummy

cd  python-dummy

cat PKGBUILD 
pkgname='python'
pkgver=99.1
pkgrel=1
arch=(any)
provides=('python') 

src:https://bbs.archlinux.org/viewtopic.php?id=238210 

using loacl anaconda python and pip 

add site package to conda 

ls  -d1 /usr/lib/python*/site-packages

/usr/lib/python3.11/site-packages

• -d tell ls list directories themselves, not their content
• -1 tell ls list one entry per line

 

python3.11

export PYTHONPATH="/usr/lib/python3.11/site-packages:$PYTHONPATH"

sudo --preserve-env=PYTHONPATH iotop

makepkg 

pacman -U python-0.1-1-any.pkg.tar.zst

https://github.com/kzwkt/pacman-dummy

policy 0-3

>cat /sys/devices/system/cpu/cpufreq/policy*/energy_performance_available_preferences
default performance balance_performance balance_power power
default performance balance_performance balance_power power
default performance balance_performance balance_power power
default performance balance_performance balance_power power 

/etc/tmpfiles.d/energy_performance_preference.conf

w /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference - - - - balance_power

/etc/modprobe.d/audio_powersave.conf

options snd_hda_intel power_save=1

 or 

options snd_ac97_codec power_save=1

 blacklist snd_hda_codec_hdmi

blacklist btusb and bluetooth modules. 

rfkill block bluetooth

/etc/udev/rules.d/50-bluetooth.rules
# disable bluetooth
SUBSYSTEM=="rfkill", ATTR{type}=="bluetooth", ATTR{state}="0"

camera blacklist uvcvideo module

/etc/sysctl.d/disable_watchdog.conf
kernel.nmi_watchdog = 0

or add nmi_watchdog=0

/etc/sysctl.d/dirty.conf
vm.dirty_writeback_centisecs = 6000

Increasing the virtual memory dirty writeback time helps to aggregate 
disk I/O together, thus reducing spanned disk writes, and increasing 
power saving. To set the value to 60 seconds (default is 5 seconds): 

To do the same for journal commits on supported filesystems (e.g. ext4, btrfs...), use commit=60 as a option in fstab.   

/etc/sysctl.d/laptop.conf

vm.laptop_mode = 5

This setting is mainly relevant to spinning-disk drives. 

/etc/udev/rules.d/81-wifi-powersave.rules

ACTION=="add", SUBSYSTEM=="net", KERNEL=="wl*", RUN+="/usr/bin/iw dev $name set power_save on"

cat /sys/block/sda/queue/scheduler
none [mq-deadline] kyber bfq 

grep "" /sys/block/*/queue/scheduler
/sys/block/nvme0n1/queue/scheduler:[none] mq-deadline kyber bfq 
/sys/block/sda/queue/scheduler:none [mq-deadline] kyber bfq 

echo bfq > /sys/block/sda/queue/scheduler

/etc/udev/rules.d/60-ioschedulers.rules
# HDD
ACTION=="add|change", KERNEL=="sd[a-z]*", ATTR{queue/rotational}=="1", ATTR{queue/scheduler}="bfq"

# SSD
ACTION=="add|change", KERNEL=="sd[a-z]*|mmcblk[0-9]*", ATTR{queue/rotational}=="0", ATTR{queue/scheduler}="bfq"

# NVMe SSD
ACTION=="add|change", KERNEL=="nvme[0-9]*", ATTR{queue/rotational}=="0", ATTR{queue/scheduler}="none" 

ls /sys/block/sda/queue/iosched
async_depth  fifo_batch  front_merges  prio_aging_expire  read_expire  write_expire  writes_starved

makepkg in /tmp 

BUILDDIR=/tmp/makepkg makepkg

 /etc/makepkg.conf

BUILDDIR=/tmp/makepkg

• Avoid compiling larger packages in tmpfs to prevent running out of memory.
• The tmpfs directory must be mounted without the noexec option, otherwise it will prevent built binaries from being executed.
• Keep in mind that packages compiled in tmpfs will not persist across reboot. Consider setting the PKGDEST option appropriately to move the built package automatically to a persistent directory.

Starting with Gen9 (Skylake and onwards), Intel GPUs include a Graphics micro (μ) Controller (GuC) which provides the following functionality

• Offloading some media decoding functionality from the CPU to the HEVC/H.265 micro (µ) Controller (HuC). Only applicable if using intel-media-driver for hardware video acceleration. Introduced with Gen9.
• Using the GuC for scheduling, context submission, and power management. Introduced with Alder Lake-P (Mobile), within Gen12.

To use this functionality, the GuC firmware must be loaded. With regards to HuC support, some video features (e.g. CBR rate control on SKL low-power encoding mode) require loading the HuC firmware as well [6]. The GuC and HuC firmware files are both provided by linux-firmware. 

 

/etc/modprobe.d/i915.conf

options i915 enable_guc=2

options i915 enable_fbc=1 

Framebuffer compression (FBC) is a feature that can reduce power consumption and memory bandwidth during screen refreshes. 

 

modinfo i915 | grep enable_fbc
parm:           enable_fbc:Enable frame buffer compression for power savings (default: -1 (use per-chip default)) (int)

 If the parm is set to -1, you do not need to do anything

options i915 fastboot=1

The goal of Intel Fastboot is to preserve the frame-buffer as setup by the BIOS or boot loader to avoid any flickering until Xorg has started.[14][15] 

 

Keyboard Shortcut	Description	Code to Enable	Other Functions Enabled
Alt+SysRq+r Unraw	Take control of keyboard back from X.	4	Alt+SysRq+k SAK
Alt+SysRq+e Terminate	Send SIGTERM to all processes, allowing them to terminate gracefully.	64	Alt+SysRq+f OOM kill Alt+SysRq+j Thaw
Alt+SysRq+i Kill	Send SIGKILL to all processes, forcing them to terminate immediately.
Alt+SysRq+s Sync	Flush data to disk.	16	-
Alt+SysRq+u Unmount	Unmount and remount all filesystems read-only.	32	-
Alt+SysRq+b Reboot	Reboot	128	-

A common idiom to remember this is "Reboot Even If System Utterly Broken" (also referred to as "REISUB"). Alternatively, think of it as "BUSIER" backwards. 

in dell  SysRq = print sc(F10)


ln -sfT dash /usr/bin/sh