Arch Linux User Repository

This package have several variables to enable/disable features.

##
## The following variables can be customized at build time. Use env or export to change at your wish
##
##   Example: env _microarchitecture=98 use_numa=n use_tracers=n makepkg -sc
##
## Look inside 'choose-gcc-optimization.sh' to choose your microarchitecture
## Valid numbers between: 0 to 99
## Default is: 0 => generic
## Good option if your package is for one machine: 98 (Intel native) or 99 (AMD native)
if [ -z ${_microarchitecture+x} ]; then
  _microarchitecture=0
fi

## Disable NUMA since most users do not have multiple processors. Breaks CUDA/NvEnc.
## Archlinux and Xanmod enable it by default.
## Set variable "use_numa" to: n to disable (possibly increase performance)
##                             y to enable  (stock default)
if [ -z ${use_numa+x} ]; then
  use_numa=y
fi

## Since upstream disabled CONFIG_STACK_TRACER (limits debugging and analyzing of the kernel)
## you can enable them setting this option. Caution, because they have an impact in performance.
## Stock Archlinux has this enabled. 
## Set variable "use_tracers" to: n to disable (possibly increase performance, XanMod default)
##                                y to enable  (Archlinux default)
if [ -z ${use_tracers+x} ]; then
  use_tracers=n
fi

# Unique compiler supported upstream is GCC
## Choose between GCC and CLANG config (default is GCC)
## Use the environment variable "_compiler=clang"
if [ "${_compiler}" = "clang" ]; then
  _compiler_flags="CC=clang HOSTCC=clang LLVM=1 LLVM_IAS=1"
fi

# Choose between the 4 main configs for stable branch. Default x86-64-v1 which use CONFIG_GENERIC_CPU2:
# Possible values: config_x86-64-v1 (default) / config_x86-64-v2 / config_x86-64-v3 / config_x86-64-v4
# This will be overwritten by selecting any option in microarchitecture script
# Source files: https://github.com/xanmod/linux/tree/5.17/CONFIGS/xanmod/gcc
if [ -z ${_config+x} ]; then
  _config=config_x86-64-v1
fi

# Compress modules with ZSTD (to save disk space)
if [ -z ${_compress_modules+x} ]; then
  _compress_modules=n
fi

# Compile ONLY used modules to VASTLY reduce the number of modules built
# and the build time.
#
# To keep track of which modules are needed for your specific system/hardware,
# give module_db script a try: https://aur.archlinux.org/packages/modprobed-db
# This PKGBUILD read the database kept if it exists
#
# More at this wiki page ---> https://wiki.archlinux.org/index.php/Modprobed-db
if [ -z ${_localmodcfg} ]; then
  _localmodcfg=n
fi

# Tweak kernel options prior to a build via nconfig
if [ -z ${_makenconfig} ]; then
  _makenconfig=n
fi

Personally I'm running now xanmod kernel compiled with this:

env _microarchitecture=98 use_tracers=n use_numa=n _localmodcfg=y _compress_modules=y makepkg -sic

Also, you can now create the file myconfig in your local repo to build this package with a custom config or use ${XDG_CONFIG_HOME}/linux-xanmod/myconfig. This file can be a full kernel config or be a script with several entries to add/remove options (you have several examples in PKGBUILD by using scripts/config):

Code involved:

  for _myconfig in "${SRCDEST}/myconfig" "${HOME}/.config/linux-xanmod/myconfig" "${XDG_CONFIG_HOME}/linux-xanmod/myconfig" ; do
    if [ -f "${_myconfig}" ] && [ "$(wc -l <"${_myconfig}")" -gt "0" ]; then
      if grep -q 'scripts/config' "${_myconfig}"; then
        # myconfig is a partial file. Executing as a script
        msg2 "Applying myconfig..."
        bash -x "${_myconfig}"
      else
        # myconfig is a full config file. Replacing default .config
        msg2 "Using user CUSTOM config..."
        cp -f "${_myconfig}" .config
      fi
      echo
      break
    fi
  done

i previosly installed it with pamac, if clone repo and manualy build it works.

@IsNoGood mmm I'm not sure what's is going on...

In my current laptop I have this:

figue@pluto ~ % uname -a
Linux pluto 5.8.12-xanmod1-1 #1 SMP PREEMPT Mon, 28 Sep 2020 06:12:21 +0000 x86_64 GNU/Linux

figue@pluto ~ % zgrep USER_NS /proc/config.gz
CONFIG_USER_NS=y
CONFIG_USER_NS_UNPRIVILEGED=y

figue@pluto ~ % cat packages-figue/linux-xanmod/build.sh 
#!/usr/bin/env bash
export LANG=C
_microarchitecture=42 use_numa=n use_tracers=n use_ns=y _localmodcfg=y use_cachy=y makepkg $*

@Sourav I'm not using custom flags actually, only flags provided by Xanmod in GCC optimization (see https://github.com/xanmod/linux/commit/bafdc4b2d355ff81814678ba221d538763b497a0). In PKGBUILD I don't change or ignore CC flags... Should be another thing.

how to correctly apply following settings?

 env _microarchitecture=42 use_numa=n use_tracers=n use_pds=n use_ns=y use_cachy=y makepkg -si

Even if i type "env _microarchitecture=42 use_numa=n use_tracers=n use_pds=n use_ns=y use_cachy=y" in console it shows that settings added to env but after compile i get error

cannot clone: Operation not permitted
user namespaces are not enabled in /proc/sys/kernel/unprivileged_userns_clone
Error: cannot re-exec process

See, the CC, and CFLAGS inside /etc/makepkg.conf are completely ignored by the makepkg -si inside linux-xanmod. But flags like: MAKEFLAGS="-j$(( `nproc` * 2 + 1 ))" is working flawlessly.

It used to work till the 5.8.8 which I compiled last.

In this version, I was trying to use clang, but it kept using gcc. It's ignoring clang and the optimization flags in this version. Even env variable isn't working, perhaps something overriding those inside PKGBUILD? I have to thus modify the make all line inside PKGBUILD, which also works just fine.

What do you add exactly? Why not modifying /etc/makepkg.conf or use a custom with "makepkg --config /etc/makepkg.conf_O3" for instance...

@figue, yes I used _microarchitecture=0 for others and _microarchitecture=42 for myself:

env _microarchitecture=0 use_numa=n use_tracers=n use_pds=n use_ns=y use_cachy=y makepkg -si

But I now need to modify the build() in PKGBUID to add the CFLAGS for the optimization I needed.

@Sourav do you build it with default _microarchitecture?

It's now ignoring other CC and is using GCC by default. Also optimization flags like -O3, -mtune=native, -march=native is ignored? Why?

already tried with different build combination but i get this error every time,and system fails to boot. changing compression method didn't help either.

==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-linux-xanmod-fallback.img
==> WARNING: errors were encountered during the build. The image may not be complete.
error: command failed to execute correctly

My build crashes.

The last couple lines are

patching file tools/testing/selftests/x86/test_vsyscall.c
patching file usr/Kconfig
patching file usr/Makefile
patching file virt/kvm/kvm_main.c
==> ERROR: A failure occurred in prepare().
    Aborting...