On Sat, Jun 29, 2024 at 10:13 AM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote: > > Hi, > > I wanted to test the impact on build-time with Linux v6.9.7. > > The motivation was to build with and without this revert: > > $ git revert f1feed67c79e > ( Revert "kbuild: Remove support for Clang's ThinLTO caching" ) > > As I read about pahole issues with LLVM/Clang and LTO in the > ClangBuiltLinux BTS I used pahole/next.git. > > $ git log --oneline tags/v1.27.. > 693522ee3a94 (HEAD -> pahole-next-v1.27-7-g693522ee3a94, > origin/tmp.master, origin/next, next) core: Ignore DW_TAG_inheritance > with byte_size zero when finding holes > 43f9515d8211 dwarf_loader: Print the DWARF offset in > tag__print_unsupported_tag() > e82a0fdcfb8e dwarf_loader: Simplify tag__print_not_supported() > f7e3f0942fed pahole: Bail out when not finding debug anywhere > 94a01bde592c dwarf_loader: Add missing cus__add(cus, cu) to > cus__merge_and_process_cu() > 6a2b27c0f512 core: Initialize cu->node with INIT_LIST_HEAD() > 0ce7745fa46d PKG-MAINTAINERS: Add maintainer for nixpkgs package > > DWARF-v5 was enabled. > > The slim LLVM toolchain version 18.1.8 from kernel.org was used (Thanks Nathan). > Link: https://mirrors.edge.kernel.org/pub/tools/llvm/ > > This constellation is BROKEN in the modfinal/BTF section: > > # BTF [M] drivers/gpu/drm/i915/i915.ko > if [ ! -f vmlinux ]; then printf "Skipping BTF generation for %s due > to unavailability of vmlinux > " drivers/gpu/drm/i915/i915.ko 1>&2; else LLVM_OBJCOPY="llvm-objcopy" > /opt/pahole/bin/pahole -J --btf_gen_floats -j --lang_exclude=rust > --skip_encoding_btf_inconsistent_proto --btf_gen_optimized --btf_base > vmlinux drivers/gpu/drm/i915/i915.ko; > ./tools/bpf/resolve_btfids/resolve_btfids -b vmlinux > drivers/gpu/drm/i915/i915.ko; fi; > ld.lld: error: drivers/gpu/drm/nouveau/nouveau.o:(.debug_str): offset > is outside the section > make[5]: *** [scripts/Makefile.modfinal:57: > drivers/gpu/drm/nouveau/nouveau.ko] Error 1 > make[5]: *** Waiting for unfinished jobs.... > ld.lld: error: drivers/gpu/drm/amd/amdgpu/amdgpu.o:(.debug_info+0x7d117f5): > unknown relocation (33554442) against symbol > make[5]: *** [scripts/Makefile.modfinal:56: > drivers/gpu/drm/amd/amdgpu/amdgpu.ko] Error 1 > make[4]: *** [Makefile:1852: modules] Error 2 > make[3]: *** [debian/rules:74: build-arch] Error 2 > dpkg-buildpackage: error: make -f debian/rules binary subprocess > returned exit status 2 > make[2]: *** [scripts/Makefile.package:121: bindeb-pkg] Error 2 > make[1]: *** [/home/dileks/src/linux/git/Makefile:1541: bindeb-pkg] Error 2 > make: *** [Makefile:240: __sub-make] Error 2 > > Before doing wild experiments I like to see a confirmation of > reproducing the ERROR. > Nathan, can you support me? > My last successful build: Linux-kernel version 6.8.10 using Debian's > pahole version 1.26. > > Attached is my linux-config which is based on Debian's kernel v6.9.7. > > Thanks. > > Best regards, > -Sedat- [ Add some BPF/BTF folks ] I found upstream commit fcd1ed89a0439c45e1336bd9649485c44b7597c7 ("kbuild,bpf: Switch to using --btf_features for pahole v1.26 and later") Can BPF/BTF folk comment? Thanks. Best regards, -Sedat-
