Rong Xu
9f2aee8f7d
Add distributed ThinLTO build support for the Linux kernel.
This new mode offers several advantages: (1) Increased
flexibility in handling user-specified build options.
(2) Improved user-friendliness for developers. (3) Greater
convenience for integrating with objtool and livepatch.
Note that "distributed" in this context refers to a term
that differentiates in-process ThinLTO builds by invoking
backend compilation through the linker, not necessarily
building in distributed environments.
Distributed ThinLTO is enabled via the
`CONFIG_LTO_CLANG_THIN_DIST` Kconfig option. For example:
> make LLVM=1 defconfig
> scripts/config -e LTO_CLANG_THIN_DIST
> make LLVM=1 oldconfig
> make LLVM=1 vmlinux -j <..>
The build flow proceeds in four stages:
1. Perform FE compilation, mirroring the in-process ThinLTO mode.
2. Thin-link the generated IR files and object files.
3. Find all IR files and perform BE compilation, using the flags
stored in the .*.o.cmd files.
4. Link the BE results to generate the final vmlinux.o.
NOTE: This patch currently implements the build for the main kernel
image (vmlinux) only. Kernel module support is planned for a
subsequent patch.
Tested on the following arch: x86, arm64, loongarch, and
riscv.
The earlier implementation details can be found here:
https://discourse.llvm.org/t/rfc-distributed-thinlto-build-for-kernel/85934
Signed-off-by: Rong Xu <xur@google.com>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Piotr Gorski <piotrgorski@cachyos.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260529185347.2418373-4-xur@google.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
193 lines
2.3 KiB
Plaintext
193 lines
2.3 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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#
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# NOTE! Don't add files that are generated in specific
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# subdirectories here. Add them in the ".gitignore" file
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# in that subdirectory instead.
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#
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# NOTE! Please use 'git ls-files -i -c --exclude-per-directory=.gitignore'
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# command after changing this file, to see if there are
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# any tracked files which get ignored after the change.
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#
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# Normal rules (sorted alphabetically)
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#
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.*
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*.a
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*.asn1.[ch]
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*.bc
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*.bin
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*.bz2
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*.c.[012]*.*
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*.dt.yaml
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*.dtb
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*.dtbo
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*.dtb.S
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*.dtbo.S
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*.dwo
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*.dylib
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*.elf
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*.gcno
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*.gcda
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*.gz
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*.i
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*.ko
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*.lex.c
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*.ll
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*.lst
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*.lz4
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*.lzma
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*.lzo
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*.mod
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*.mod.c
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*.o
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*.o.*
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*.patch
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*.pyc
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*.rlib
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*.rmeta
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*.rpm
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*.rsi
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*.s
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*.so
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*.so.dbg
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*.su
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*.symtypes
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*.tab.[ch]
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*.tar
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*.xz
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*.zst
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Module.symvers
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dtbs-list
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builtin.order
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modules.order
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#
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# Top-level generic files
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#
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/linux
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/modules-only.symvers
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/vmlinux
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/vmlinux.32
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/vmlinux.map
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/vmlinux.symvers
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/vmlinux.thinlto-index
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/vmlinux.unstripped
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/vmlinux-gdb.py
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/vmlinuz
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/System.map
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/Module.markers
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/modules.builtin
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/modules.builtin.modinfo
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/modules.builtin.ranges
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/modules.nsdeps
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#
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# RPM spec file (make rpm-pkg)
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#
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/rpmbuild/
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#
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# Debian directory (make deb-pkg)
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#
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/debian/
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#
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# Snap directory (make snap-pkg)
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#
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/snap/
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#
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# tar directory (make tar*-pkg)
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#
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/tar-install/
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#
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# pacman files (make pacman-pkg)
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#
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/PKGBUILD
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/pacman/
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#
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# We don't want to ignore the following even if they are dot-files
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#
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!.clang-format
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!.clippy.toml
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!.cocciconfig
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!.editorconfig
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!.get_maintainer.ignore
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!.gitattributes
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!.gitignore
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!.kunitconfig
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!.mailmap
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!.pylintrc
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!.rustfmt.toml
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#
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# Generated include files
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#
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/include/config/
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/include/generated/
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/arch/*/include/generated/
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# stgit generated dirs
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patches-*
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# quilt's files
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patches
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series
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# ctags files
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tags
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!tags/
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TAGS
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# cscope files
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cscope.*
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ncscope.*
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# gnu global files
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GPATH
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GRTAGS
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GSYMS
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GTAGS
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# id-utils files
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ID
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*~
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\#*#
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#
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# Leavings from module signing
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#
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extra_certificates
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signing_key.pem
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signing_key.priv
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signing_key.x509
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x509.genkey
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# Kconfig presets
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/all.config
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/alldef.config
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/allmod.config
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/allno.config
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/allrandom.config
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/allyes.config
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# Kconfig savedefconfig output
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/defconfig
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# Kdevelop4
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*.kdev4
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# Clang's compilation database file
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compile_commands.json
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# Documentation toolchain
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sphinx_*/
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# Rust analyzer configuration
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/rust-project.json
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# bc language scripts (not LLVM bitcode)
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!kernel/time/timeconst.bc
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