* David Woodhouse <dw...@infradead.org> wrote: > > > On Mon, 2018-02-05 at 16:56 -0300, Arnaldo Carvalho de Melo wrote: > > > > None will entail changes in the tools/perf/, synchronizing to elliminate > > these perf build warnings: > > > > Warning: Kernel ABI header at > > 'tools/arch/x86/include/asm/disabled-features.h' differs from latest > > version at 'arch/x86/include/asm/disabled-features.h' > > Warning: Kernel ABI header at > > 'tools/arch/x86/include/asm/required-features.h' differs from latest > > version at 'arch/x86/include/asm/required-features.h' > > Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' > > differs from latest version at 'arch/x86/include/asm/cpufeatures.h' > > Ick. Have we considered just using a symlink? Why have copies of the > same header file in different places in the tree, and tooling to > complain i̶f̶when they get out of sync?
In the past we had incidents where kernel changes broke tooling and vice versa. This is basically a soft-COW mechanism that decouples tooling source code from the kernel source code, while still having a technological mechanism in place that encourages the syncing of header files. Thanks, Ingo