Em Thu, Jun 06, 2019 at 05:48:45PM +0800, Leo Yan escreveu: > To build this program successfully with clang, there have three > compiler options need to be specified: > > - Header file path: tools/perf/include/bpf; > - Specify architecture; > - Define macro __NR_CPUS__. So, this shouldn't be needed, all of this is supposed to be done automagically, have you done a 'make -C tools/perf install'? - Arnaldo > This patch add comments to explain the reasons for building failure and > give two examples for llvm.clang-opt variable, one is for x86_64 > architecture and another is for aarch64 architecture. > > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx> > --- > .../examples/bpf/augmented_raw_syscalls.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c > index a3701a4daf2e..fb6987edab2c 100644 > --- a/tools/perf/examples/bpf/augmented_raw_syscalls.c > +++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c > @@ -6,6 +6,25 @@ > * > * perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c cat /etc/passwd > /dev/null > * > + * This program include two header files 'unistd.h' and 'pid_filter.h', which > + * are placed in the folder tools/perf/include/bpf, but this folder is not > + * included in env $KERNEL_INC_OPTIONS and it leads to compilation failure. > + * For building this code, we also need to specify architecture and define macro > + * __NR_CPUS__. To resolve these issues, variable llvm.clang-opt can be set in > + * the file ~/.perfconfig: > + * > + * E.g. Test on a platform with 8 CPUs with x86_64 architecture: > + * > + * [llvm] > + * clang-opt = "-D__NR_CPUS__=8 -D__x86_64__ \ > + * -I./tools/perf/include/bpf" > + * > + * E.g. Test on a platform with 5 CPUs with aarch64 architecture: > + * > + * [llvm] > + * clang-opt = "-D__NR_CPUS__=5 -D__aarch64__ \ > + * -I./tools/perf/include/bpf" > + > * This exactly matches what is marshalled into the raw_syscall:sys_enter > * payload expected by the 'perf trace' beautifiers. > * > -- > 2.17.1 -- - Arnaldo
